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100-274
• STATE OF ALASKA 0 ALASKA OIL AND GAS CONSERVATION COMMISSION WELL COMPLETION OR RECOMPLETION REPORT AND LOG 1 a. Well Status: Oil ❑ Gas ❑ SPLUG ❑ Other ❑ Abandoned ❑✓ Suspended ❑ 20AAC 25.105 20AAC 25.116 GINJ ❑ WINJ ❑ WAGE] WDSPL ❑ No. of Completions: 1 b. Well Class: Development ❑ Exploratory [✓ Service Strati ra hic Test 2. Operator Name: M -W Drilling, Inc. (Contractor) 6. Date Comp., Susp., or Aband.: g( -?q ILS 14. Permit to Drill Number/ Sundry: 100-274 3. Address: PO Box 110389 Anchorage AK 99511 7. Date Spudded: 1982 15. API Number: 50-031-20004-00-00 4a. Location of Well (Governmental Section): Surface: Top of Productive Interval: 187.4' Total Depth: 881' (open to 492') 8. Date TD Reached: 1982 16. Well Name and Number: PS -4 9. KB (ft above MSL): GL (ft above MSL): 17. Field / Pool(s): Pilgrim Hot Springs 10. Plug Back Depth MD/TVD: GR 18. Property Designation: Fee-Uaatuq, LLC 4b. Location of Well (State Base Plane Coordinates, NAD 27): Surface: x- N65 05.359' y- W164 55.735' Zone- TPI: x- y- Zone- Total Depth: x- y- Zone - 11. Total Depth MD/TVD: 881' 19. Land Use Permit: 12. SSSV Depth MD/TVD: 20. Thickness of Permafrost MD/TVD: 5. Directional or Inclination Survey: Yes ❑(attached) No ❑ Submit electronic and printed information per 20 AAC 25.050 13. Water Depth, if Offshore: (ft MSL) 21. Re-drill/Lateral Top Window MD/TVD: 22. Logs Obtained: List all logs run and, pursuant to AS 31.05.030 and 20 AAC 25.071, submit all electronic data and printed logs within 90 days of completion, suspension, or abandonment, whichever occurs first. Types of logs to be listed include, but are not limited to: mud log, spontaneous potential, gamma ray, caliper, resistivity, porosity, magnetic resonance, dipmeter, formation tester, temperature, cement evaluation, casing collar locator, jewelry, and perforation record. Acronyms may be used. Attach a separate page if necessary RECEIVED S ►NINED JAN 2 2 2016 NOV 0 2 2015 AOGO{ i 23. CASING, LINER AND CEMENTING RECORD WT. PER GRADE SETTING DEPTH MD SETTING DEPTH TVD AMOUNT CASING FT TOP BOTTOM TOP BOTTOM HOLE SIZE CEMENTING RECORD PULLED ASTM 16" 62.58 A53B 0 19 10" 40.48 A53B 0 86.52 8" 28.55 A53B 0 187.42 24. Open to production or injection? Yes ❑ No If Yes, list each interval open (MD/TVD of Top and Bottom; Perforation Size and Number): See sketch. 25. TUBING RECORD SIZE DEPTH SET (MD) PACKER SET (MD/TVD) 26. ACID, FRACTURE, CEMENT SQUEEZE, ETC. Was hydraulic fracturing used during completion? Yes ❑ No Per 20 AAC 25.283 (i)(2) attach electronic and printed information DEPTH INTERVAL (MD) AMOUNT AND KIND OF MATERIAL USED 27. PRODUCTION TEST Date First Production: Method of Operation (Flowing, gas lift, etc.): Date of Test: Hours Tested: Production for Test Period -11101 Oil -Bbl: Gas -MCF: Water -Bbl: Choke Size:Gas Oil Ratio: Flow Tubing Press. Casinq Press: Calculated 24 -Hour Rate Oil -Bbl: Gas -MCF: Water -Bbl: Oil Gravity - API (corr): Form 10-407 Revised 5/2015 % �(, �ONTINUED ON PAGE 2 RBDM NOV O 1015 Submit ORIGINIAL only �l�r!� 28. tiGRE DATA Conventional re(s): Yes ❑ No Sidewall Core Yes ❑ No [l If Yes, list formations and intervals cored (MD/TVD, From/To), and summarize lithology and presence of oil, gas or water (submit separate pages with this form, if needed). Submit detailed descriptions, core chips, photographs, and all subsequent laboratory analytical results per 20 AAC 25.071. 29. GEOLOGIC MARKERS (List all formations and markers encountered): 30. FORMATION TESTS NAME MD TVD Well tested? Yes ❑ No E] If yes, list intervals and formations tested, briefly summarizing test results. Permafrost - Top Permafrost - Base Attach separate pages to this form, if needed, and submit detailed test information, including reports, per 20 AAC 25.071. Formation at total depth: 31. List of Attachments: 1. Estimated well sketch 3. P&A Summary 2. Pictures 4. Slurry Mix Information to be attached includes, but is not limited to: summary of daily operations, wellbore schematic, directional or inclination survey, core analysis, paleontological report, production or well test results, per 20 AAC 25.070. 32. 1 hereby certify that the foregoing is true and correct to the best of my knowledge. Contact: MW Drilling, Inc. Email: mw mwdrillin Iflc.com Printed Name: Wayne Wgstberg Title: President Signature: Phone: 907-345-4000 Date: MOOS INSTRUCTIONS General: This form and the required attach me provide a complete and concise record for each well drilled in Alaska. Submit a well schematic diagram with each 10-407 well completion report and 10-404 well sundry report when the downhole well design is changed. All laboratory analytical reports regarding samples or tests from a well must be submitted to the AOGCC, no matter when the analyses are conducted. Item 1a: Multiple completion is defined as a well producing from more than one pool with production from each pool completely segregated. Each segregated pool is a completion. Item 1b: Well Class - Service wells: Gas Injection, Water Injection, Water -Alternating -Gas Injection, Salt Water Disposal, Water Supply for Injection, Observation, or Other. Item 4b: TPI (Top of Producing Interval). Item 9: The Kelly Bushing and Ground Level elevations in feet above mean sea level. Use same as reference for depth measurements given in other spaces on this form and in any attachments. Item 15: The API number reported to AOGCC must be 14 digits (ex: 50-029-20123-00-00). Item 20: Report measured depth and true vertical thickness of permafrost. Provide MD and TVD for the top and base of permafrost in Box 29. Item 22: Review the reporting requirements of 20 AAC 25.071 and, pursuant to AS 31.05.030, submit all electronic data and printed logs within 90 days of completion, suspension, or abandonment, whichever occurs first. Item 23: Attached supplemental records should show the details of any multiple stage cementing and the location of the cementing tool. Item 24: If this well is completed for separate production from more than one interval (multiple completion), so state in item 1, and in item 23 show the producing intervals for only the interval reported in item 26. (Submit a separate form for each additional interval to be separately produced, showing the data pertinent to such interval). Item 27: Method of Operation: Flowing, Gas Lift, Rod Pump, Hydraulic Pump, Submersible, Water Injection, Gas Injection, Shut-in, or Other (explain). Item 28: Provide a listing of intervals cored and the corresponding formations, and a brief description in this box. Pursuant to 20 AAC 25.071, submit detailed descriptions, core chips, photographs, and all subsequent laboratory analytical results, including, but not limited to: porosity, permeability, fluid saturation, fluid composition, fluid fluorescence, vitrinite reflectance, geochemical, or paleontology. Item 30: Provide a listing of intervals tested and the corresponding formation, and a brief summary in this box. Submit detailed test and analytical laboratory information required by 20 AAC 25.071. Item 31: Pursuant to 20 AAC 25.070, attach to this form: well schematic diagram, summary of daily well operations, directional or inclination survey, and other tests as required including, but not limited to: core analysis, paleontological report, production or well test results. Form 10-407 Revised 5/2015 Submit ORIGINAL Only 0 19 104nah M46tv wive 24rich outiou vAth v#Ivft - G.L. loft 30 ft 96,5 ft cor"At 180 ft - 187.4 ft S ft drill P104. 3 drlik wilars, 7 -lis In, stabillm, sub floe & bit for tow lono of 702 ft of stool left In hoto - TD di,114d 801 ft PSA 104no blind five with I � .oh nipple for flow Cutoff & weld ID plate at surface -inch coolng 19 ft; is ent in 204nch 110* Cement (16 cf) Mud v6.52 ft: 104neh wino and IL ii - trio halt Sand 187.42 ft:11-inch Ming if, 6.718 inch Koh :::712Well open to 490' OW halo 6118 inch to 520 ft; 7.714 Inch below Drilled 1982 Now open to 492' LW d04 Iftm In, OP*n h01* UP to 810' rajeM No. Fi r8 CAS1 15MA Piwim Swim NG PROFILE OF WELL PS -4 7 I vb"W" 04wide comuftwAs .W. u t x. — a 0-1 y FP's -3s i - . •-tit: _ - - i t .W. u t x. — a 0-1 y FP's -3s i - . •-tit: _ - - i /) r , , r , r y r w � Y f w « ' Yf `d > l _ � r I 1,. M -W Drilling, Inc. Work Summary - Pilgrim Hot Springs PS -4 1. Setup and unbolt (well head) master valve - well flowing 100+ qpm 2. Mix and top pump thick mud/sand to kill flow 3. Next morning well flowing again at reduced rate. Reinstalled master valve, hooked to 2" side port outlet, mixed mud (with barite) and pumped 40 cf which killed the flow 4. Pull the master valve 5. Ran 1.5" tremie to 180' and pumped 184 cf of cement slurry 6. Pull tremie to 30' and pumped 16 cf of cement slurry 7. Cutoff casing at ground surface because of concrete sheath and weld on ID plate 8. Cleanup site and backfill with local sand ♦ P.O. Box 110389 ♦ Anchorage, AK 99511 ♦ Phone: 907-345-4000 ♦ Fax: 907-345-3287 ♦ mw@mwdrillinginc.com ♦ www.mwdrillinginc.com 0 's are our business!!! M -W Drilling, Inc. API Class A cement slurry components: - Class A Cement, 1 sack 0.48 CF - Sand, Fine 1.00 CF - Water (9 gals) 1.20 CF - Bentonite, fine grained (4 lbs) Total slurry yield for each cement sack 2.68 CF One grout mix batch equals 3 volumes of above slurry mix ♦ P.O. Box 110389 ♦ Anchorage, AK 99511 ♦ Phone: 907-345-4000 ♦ Fax: 907-345-3287 ♦ mw®mwdrillinginc.com ♦ www.mwdrillingine.com 0 's are our businessM I- L-1 TIME DRILL LOG CASING Es rilli Inc. -�' DDO® DATE CREW r`� CJ D ilY i� vl& z« - � NAME PROJ. NO. ADDRESS CITY PHONE ° JOB LOCATIO EQUIP.# °�✓ / END l START TOTAL HOURS ' Static Level GPM Yield Bas of Bentonite — 9/_ ^ fj ice'" Y r D 4"� d 'AGI DEPTH WELL LAG �t 0- CASING STICK UP TIME DRILL LOG j CASING ® s rifflin' Ili® DATE CREW i 2 J 7 .� /!w; ' F� ;�-.,,• NAME PROJ. NO. ADDRESS CITY PHONE JOB LOCATION EQUIP# f, F END r y � � n f 1� START 1 L/ 4F v e G JG TOTAL HOURS — Static Level GPM Yield Sas of Bentonite DEPTH WELL LOG — ®- CASING STICK UP The Nnw, Inc 190712-P57m Drilling, In f ,, a a'/J Alzwll- n NAME �- PROJ. N6. ADDRESS CITY� PHONE JOB LOCATION EQUIP.# END START TOTAL -AQURS Static Level GPM Yield _ Sas of Bentonite • TIME DRILL LOG CASING ILI R, f/ ✓9 {/ Jw r milt • M- D DATE ' CREW illing, Inc. zw ADDRESS I i B y CITY l PHONE JOB LOCATION EQUIP.# END START TOTAL Static Level GPM Yield of Bentonite DEPTH I WELL LOG 0- CASING STICK UP 6 • TIME DRILL LOC CASING -7/77 WoAf k6� ilY 4 � p • I', Drilling, E 0 TIME DRILL LOG CASING - Drilling, Inc® DATE - CREW - PROJ. NO. 10 ADDRESS CITY PHONE JOB LOCATION ���W'/ EQUIP# END START TOTAL HOURS Static Level GPM field Bas of Bentonite DEPTH WELL LOG 0- CASING STICK UP PILGRIM SPRINGS GEOTHERMAL WELLS WELL NAME PTD No. OPERATOR OF RECORD Location DATE TOTAL DEPTH STATUS DRILLED (feet) 0 �v Pilgrim Springs -1 179-078 SOA, Division of Energy &Power* 36, T4S, R31W, KRM 1979 150 Shut -iii S Pilgrim Springs -2 179-085 SOA, Division of Energy & Power* 03, T5S, R31W, KRM 1979 150 Shut fn Pil � -3 179-090 SOA Division of Energy & Power* 03, T5S, R31W, KRM 1982 260 Shu -in Pilgrim Springs -4 100-274 _SOA, Division of Energy & Power 03, TSS, R31W, KRM 1982 881 Sh t -in Pilgrim Springs -5 100-275 SOA, Division of Energy & Power* 03, T5S, R31W, KRM 1982 1001 S ut-in Mary's Igloo -1 100-276 SOA, Division of Energy & Power* 03, T5S, R31W, KRM 1982 307 phut-in r' ' 212-077 UAF Alaska Center for Energy & Power 36, T4S, R31W, KRM 2012 1000 Suspended PS 12-2 212-109 r & Power 36, T4S, R31W, KRM 2012 1294 Suspended PS 12-3 212-126 UAF Alaska Center for Energy & Power 3 012_ 1183 Suspended PS 13-1 213-102 UAF Alaska Center for Energy & Power 36, T4S, R31W, KRM 2013 103 SUspefj(k.4 -., *SOA, Department of Commerce and Economic Development, Division of Energy and Power Attachment 1 • Colombie, Jody J (DOA) From: Alan P. Baldivieso <ABaldivieso@aidea.org> Sent: Monday, June 15, 2015 1:57 PM To: Bettis, Patricia K (DOA) Cc: Guhl, Meredith D (DOA); Colombie, Jody J (DOA) Subject: RE: Pilgrim Springs 1-5 and Mary's Igloo 1 Hi Patricia, During our earlier conversations, Guy had indicated that the applications for sundry approvals should be submitted by the contractor selected to perform the work. I just spoke with the contractor—MW Drilling—who indicated that he intends to submit the applications later this week. I understand that Wayne Westberg from MW Drilling has been in touch with Guy to clarify expectations for the applications. Best, Alan Baldivieso Program Manager Alaska Energy Authority (907) 771-3027 From: Bettis, Patricia K (DOA)[mailto:patricia.bettis@alaska.eov] Sent: Monday, June 15, 20151:38 PM To: Alan P. Baldivieso Cc: Guhl, Meredith D (DOA); Colombie, JodyJ (DOA) Subject: Pilgrim Springs 1-5 and Mary's Igloo 1 Good afternoon Alan, The AOGCC has not received any sundry applications for the plugging and abandonment of the Pilgrim Springs 1-5 and Mary's Igloo 1 wells. Does AEA plan to submit those application in the near future? Thank you, Patricia Patricia Bettis Senior Petroleum Geologist Alaska Oil and Gas Conservation Commission 333 West 7th Avenue Anchorage, AK 99501 Tel: (907) 793-1238 CONFIDENTIALITY NOTICE. This e-mail message, including any attachments, contains information from the Alaska Oil and Gas Conservation Commission (AOGCC), State of Alaska and is for the sole use of the intended recipient(s). It may contain confidential and/or privileged information. The unauthorized review, use or disclosure of such information may violate state or federal law. If you are an unintended recipient of this e-mail, please delete it, without first saving or forwarding it, and, so that the AOGCC is aware of the mistake in sending it to you, contact Patricia Bettis at (907) 793-1238 or patricia.bettis@alaska.eov. ALASKA � ENERGY AUTHORITY March 9, 2015 Commissioner Cathy Foerster Alaska Oil and Gas Conservation Commission 333 West 7th Avenue Anchorage, AK 99501 Re: Pilgrim Hot Springs Geothermal Wells Docket No: OTH-14-019 Dear Commissioner Foerster: The Alaska Oil and Gas Conservation Commission (AOGCC) has requested that the Alaska Department of Commerce, Community, and Economic Development (DCCED) submit a plan to suspend or plug and abandon six geothermal wells: Pilgrim Springs 1 - 5 and Mary's Igloo 1. The Alaska Energy Authority (AEA) is working on behalf of DCCED to develop a plan for these wells in compliance with 20 AAC 25.105 and 20 AAC 25.112. Alan Baldivieso, AEA geothermal program manager, has consulted with Patricia Bettis and Guy Schwartz at AOGCC to gather information and outline the steps required to plug and abandon all six wells. Alan has also contacted representatives of local landowners to confirm this is the preferred outcome. Based on these conversations and recommendations from AOGCC staff, AEA proposes to solicit bids through AEA's procurement process and select a contractor to perform the work; submit applications for sundry approval for the six wells to AOGCC; plug the wells according to the accepted plan with work estimated to be completed by September 30, 2015. I understand AOGCC staff has voiced support with the proposed course of action. Please let me know if you require additional information. Si ely, S a isher-Goad Executive Director cc: Fred Parady, DCCED Acting Commissioner R • 813 West Northern Lights Boulevard Anchorage, Alaska 99503 T 907.7713000 Toll Free (Alaska Only) 888.300.8534 F 907.771.3044 THE STATE 0 'A L A S" K, -,, - A �, GOVERNOR BILL WALKER January 7, 2015 CERTIFIED MAIL — RETURN RECEIPT REQUESTED 7012 3050 00014812 6839 Alaska Oil and Gas Conservation CornmissiGri Fred Parady Acting Commissioner Alaska Department of Commerce, Community, and Economic Development P.O. Box 110800 Juneau, AK 99811-0800 Re: Pilgrim Springs Geothermal Wells -Request for Extension Docket No: OTH-14-019 Dear Mr. Parady: 333 West Seventh Avenue Anchorage, Alaska 99501-3572 Main: 907.279.1433 Fax: 907.276.7542 www.aogcc.olaska.gov The Alaska Oil and Gas Conservation Commission (AOGCC) received the Alaska Department of Commerce, Community, and Economic Development's (DCCED) request for an extension to the December 15, 2014 deadline for submittal of an acceptable plan and schedule for either the plugging and abandoning in compliance with 20 AAC 25.105 and 20 AAC 25.112 or suspension under 20 AAC 25.110 for the Pilgrim Springs -1 through 5 and the Mary's Igloo -1 geothermal wells. The AOGCC hereby GRANTS an extension until March 10, 2015 for the submittal of an acceptable plan and schedule for either the plugging and abandoning or suspension of the Pilgrim Springs 1 through 5 and the Mary's Igloo 1 geothermal wells. If the AOGCC does not receive an acceptable plan and schedule for the fore -mentioned wells, the AOGCC will notice a public hearing to determine whether remedial action is necessary with regard to the wells and which entity will bear responsibility for compliance. Please call Ms. Patricia Bettis at (907) 793-1238 if you have questions concerning this matter. Sincerely, Cat y PZFoerster Chair, Commissioner l�S. Postal Service TM CERTIFIED MAILTM RECEIPT (©omesfic Mail Only; No /nsurance Coverage Provided) For dero livery Information visit our website at www.usps.coma ru rZI _. Postage �® ■ Complete items 1, 2, and 3. Also complete item 4 if Restricted Delivery is desired. ® Print your name and address on the reverse so that we can return the card to you. • Attach this card to the back of the mailpiece, or on the front if space permits. 1. Article Addressed to: A. Signature ❑ Agent X D Addressee B. Received by (Printed Name) C. Date of Delivery D. Is delivery,bddress differept,from item 1? D Yes If YES, enter` delivery ad&ess below: D No �T!j TE OF ALASKA I"rWINISTRATIn, `7 ",/ICES Fred Parady Acting Commissioner 3. Service Type Alaska Department of Commerce, D Certified Mail® D Priority Mail Express' Community, and Economic Development D Registered D Return Receipt for Merchandise Post Office Box 110800 D Insured Mail D Collect on Delivery Juneau, AK 99811-0800 4. Restricted Delivery? (Extra Fee) D Yes 2. Article Number ?012 3050 0001 4 812 6839 (Transfer from service label) PS Form 3311, July 2013 Domestic Return Receipt Certified Fee C3 C3 Return Receipt Fee Postmark Here (Endorsement Required) C3 Restricted Delivery Fee C3 (Endorsement Required) Ln C3 Total Postage & Fees Fred Parady rU Sent To Acting Commissioner ___________ Alaska Department of Commerce, ® Street, Apt. No.; f%- or PO Box No. Community, and Economic Development City Sfaie, ZlP+4 -------- Post Office Box 110800 :r11 Juneau, AK 99811-0800 ■ Complete items 1, 2, and 3. Also complete item 4 if Restricted Delivery is desired. ® Print your name and address on the reverse so that we can return the card to you. • Attach this card to the back of the mailpiece, or on the front if space permits. 1. Article Addressed to: A. Signature ❑ Agent X D Addressee B. Received by (Printed Name) C. Date of Delivery D. Is delivery,bddress differept,from item 1? D Yes If YES, enter` delivery ad&ess below: D No �T!j TE OF ALASKA I"rWINISTRATIn, `7 ",/ICES Fred Parady Acting Commissioner 3. Service Type Alaska Department of Commerce, D Certified Mail® D Priority Mail Express' Community, and Economic Development D Registered D Return Receipt for Merchandise Post Office Box 110800 D Insured Mail D Collect on Delivery Juneau, AK 99811-0800 4. Restricted Delivery? (Extra Fee) D Yes 2. Article Number ?012 3050 0001 4 812 6839 (Transfer from service label) PS Form 3311, July 2013 Domestic Return Receipt `F O T � THE STA'L'E Departs ent o con-arle ce, Community, U f and Economic Development C1LL'1J1\t1 OFFICE OF THE COMMISSIONER GOVERNOR BILL WALKER I P.O. Box 110800 a Juneau, Alaska 99811-0800 Main: 907.465.2500 O F I, 1 w Programs fax: 907.465.5442 December 8, 2014 Ms. Patricia Bettis Senior Petroleum Geologist Alaska Oil and Gas Conservation Commission 333 West Seventh Avenue Anchorage, AK 99501 Dear Ms. Bettis: As you know from our conversation last week, DCCED has been working diligently to respond to your letter of September 12`h regarding the Pilgrim Springs Geothermal Wells issue, Docket No: OTH-14-019. We have gathered substantial historical information and believe a proposed plan for the wells with the current project proponents is the solution although it remains unclear as to the specifics of DCCED's current responsibility and best path forward. Any action regarding the wells for which DCCED is listed as the operator appears to require coordination with the land owners Unataaq and Mary's Igloo Native Corporation. Regardless, pending completion of this research and sorting out these responsibilities, we would like to request a 60 day extension. We understand that ACEP has been or will be in contact with you regarding the four wells for which ACEP is the operator of record. Please feel free to contact me at any time regarding this matter. Sincerely, Fred Parady Acting Commissioner cc: Sara Fisher -Goad, Executive Director, Alaska Energy Authority Sean Skating, Program Development and Project Evaluation Director, Alaska Energy Authority THE STATE °'ALASKA GOVERNOR BILL WALKER Wayne E. Westberg President M -W Drilling, Inc. (ADCCED) P.O. Box 110389 Anchorage, AK 99511 Alaska Oil and Gas Conservation Commission S`pNNEp AUG 1 22015 app —3-7q Re: Pilgrim Hot Springs Field, Undefined Geothermal Pool, PS -4 Sundry Number: 315-397 Dear Mr. Westberg: 333 West Seventh Avenue Anchorage, Alaska 99501-3572 Main: 907.279.1433 Fax: 907.276.7542 www.aogcc.alaska.gov Enclosed is the approved application for sundry approval relating to the above referenced well. Please note the conditions of approval set out in the enclosed form. As provided in AS 31.05.080, within 20 days after written notice of this decision, or such further time as the AOGCC grants for good cause shown, a person affected by it may file with the AOGCC an application for reconsideration. A request for reconsideration is considered timely if it is received by 4:30 PM on the 23rd day following the date of this letter, or the next working day if the 23rd day falls on a holiday or weekend. Sincerely, 4Ca�yPloerster Chair :5f - DATED this :J1 day of July, 2015 Encl. GEIVE® UIQ 2 2 J30ii STATE OF ALASKA ALASKA OIL AND GAS CONSERVATION COMMISSION APPLICATION FOR SUNDRY APPROVALS 20 AAC 2.5280 1. Type of Request: Abandon ❑✓ Plug Perforations ❑ Fracture Stimulate ❑ Pull Tubing ❑ Operations shutdown ❑ Suspend ❑ Perforate ❑ Other Stimulate ❑ Alter Casing ❑ Change Approved Program Plug for Redrill ❑ Perforate New Pool ❑ Repair Well L1 Re-enter Susp Well ❑ Other: ❑ 2. Operator Name:/ 4. Current Well Class: 5. Permit to Drill Number: � M -W Drilling, Inc. i�o�_iT++ Exploratory Stratigraphic ❑✓ Development ❑ ❑ Service ❑ Go 3. Address: 6. API Number:q PO Box 110389, Anchorage AK 99511 50- Q3 (— 420004 "00 — 00 7. If perforating: 8. Well Name and Number: What Regulation or Conservation Order governs well spacing in this pool? PS -4 AOGC 100-274 Will planned perforations require a spacing exception? ❑ Yes No [2 9. Property Designation (Lease Number): }� 10. Field/Pool(s): qyz `' Pilgrim Hot Springs LP 11. PRESENT WELL CONDrrION SUMMARY Total Depth MD (ft): Total Depth TVD (ft): Effective Depth MD (ft): Effective Depth TVD (ft): Plugs (measured): Junk (measured): 881 yyat 492 Casing Length Size MD TVD Burst Collapse Structural Conductor 19' 16" Surface 86.52' 10" Intermediate 187.42' 8" Production None Liner Perforation Depth MD (ft):Perforation Depth TVD (ft): Tubing Size: Tubing Grade: Tubing MD (ft): None Packers and SSSV Type: Packers and SSSV MD (ft) and TVD (ft): 12. Attachments: Description Summary of Proposal ❑ 13. Well Class a er proposed work: Detailed Operations Program El BOP Sketch El Exploratory Stratigraphic ❑ Development ❑ Service ❑ 14. Estimated Date for 1 -Aug -15 15. Well Status after proposed work: Commencing Operations: OIL ❑ WINJ ❑ WDSPL ❑ Suspended ❑ GAS ❑ WAG ❑ GSTOR ❑ SPLUG ❑ 16. Verbal Approval: Date: Commission Representative: GINJ ❑ Op Shutdown ❑ Abandoned ❑ 17. 1 hereby certify that the foregoing is true and correct to the best of my knowledge. Contact Email mW@mWdl'IIIInginc.COm Printed Name Wayne E. Westber President 6/21/2015 ,11 Signature Phone 907-345-4000 �u Date COMMISSION USE ONLY Conditions of approval: Notify Commission so thlqa representative may witness Sundry Number: Plug Integrity BOP Test ❑ Mechanical Integrity Test ❑ Location Clearance ❑ Other: Y PAO/ T3 (✓� ti.fm.-..a� C 4-.S /� l.�/ [lc.�`/ /"" �-�j�, � R� Gr .� / � CO Cfr Spacing Exception Required? Yes ❑ No [� Subsequent Form Required: /0 [ APPROVED BY Approved by: COMMIS O THE COMMISSION Date: 7.3 Airzy /rUMUINAL 2z Submit Form and Form 10-403 Revised 5/2015 Approved application is valid for 12 months from the date of approval.RBDIe1v7hn1� t in Duplicate M J AUG - 2 2015 M -W Drilling, Inc. RECEIVED June 22, 2015 jUN 2 2 201'5 AC)GC To: Commissioner, Alaska Oil & Gas Conservation Commission RE: Pilgrim Hot Springs Geothermal Wells/AEA Construction Contract 15-121 Subject: Notice of Intent to Plug & Abandon 6 Geothermal Exploration Wells Dear Sir: This is to notify the commission per 11AAC87.160 our intention to plug the following geothermal wells at Pilgrim Hot Springs: PS -1 AOGC 179-078 PS -2 AOGC 179-085 PS -3 AOGC 179-090 PS -4 AOGC 100-274 PS -5 AOGC 100-275 MI -5 AOGC 100-276 Enclosed are our applications for sundry approvals. Thank you, Wa a E. Westberg, M C President M -W Drilling, Inc. ♦ P.O. Box 110389 ♦ Anchorage, AK 99511 ♦ Phone: 907-345-4000 ♦ Fax: 907-345-3287 ♦ mw@mwdrillinginc.com ♦ www.mwdrillinginc.com 's are our business!!! Attachment to Application for Sundry Approvals Description Summary of Proposal PS -4 AOGC 100-274 - Cement from bottom up to 137' - Mud and sand to 20' - Cement to surface - Cutoff well head and cap with welded %" plate on casing Project No, 15267A I Pilgrim Springs CASING PROFILE OF WELL PS -4 Figure Woodward -Clyde CAxuuftarft 7 O�'uFD /9�z 10-inch blind flange 1-inch 10-inch master valve----.C-_— with nipple for flow 2-inch outlets with valves G. L. .............. 19 ft: 16-inch casing in 20-inch hole 19 ft 86.52 ft: 10-inch casing in 14-3/ inch hole 86.5 ft Cement 0, 187.42 ft:8-inch casing r in 9-7/8 inch hole 187.4 ft ca 5 ft drill pi 3 drill collars, 1-718 instabilizer, )f� l.t& bit for subfloat & - -T' total length of 70.2 ft 2 t of steel left in hole Open hole 97/8 inch to 520 ft; 7-718 inch below P/0 Lost drill stem in open hole 4ill- TO drilled 881 ft 'New 01A, 10 Project No, 15267A I Pilgrim Springs CASING PROFILE OF WELL PS -4 Figure Woodward -Clyde CAxuuftarft 7 O�'uFD /9�z Schwartz, Guy L (DOA) From: mw@mwdrillinginc.com Sent: Wednesday, July 29, 2015 5:48 PM To: Schwartz, Guy L (DOA) Subject: AOGC Well No. 100-274 (aka PS -4): Plug and Abandonment Plan Description 1. Remove 10" blind flange and open 10" gate valve. 2. Run 1.25" tremie pipe to 490 feet or as far as it will go. 3. Cement from bottom up to 137 feet 4. Backfill with bentonite mud and sand to 23 feet 5. Cement from 23 to 3 feet below ground surface p We'd /(40t!� 6. Cutoff wellhead and casing at -3 feet from surface 7. Weld a 0.250" steel plate on the casing with the AOGC Weil number on it. 8. Note: this well was open to 492 feet in 2013. _.._ Wayne E. Westberg, MGWC 11 4 - President 01 t, M -W Drilling, Inc. 907-345-4000 Cell: 440-2536 353' 1 Schwartz, Guy L (DOA) From: mw@mwdrillinginc.com Sent: Thursday, July 30, 2015 8:33 AM To: Schwartz, Guy L (DOA) Subject: Attachment to Pilgrim P&A Plan Descriptions API Class A cement slurry components: --Class A Cement, 1 sack...............................................0.48 CF --Sand, fine......................................................................1.00 CF --Water (9 gals)............................................................... 1.2 CF --Bentonite, fine grained (4 lbs) Total slurry yield for each cement sack........ 2.68 CF Wayne E. Westberg, MGWC President M -W Drilling, Inc. 907-345-4000 Cell: 440-2536 Figure 3. PS -3 Figure 4. PS -4 (GC - ^-� 711 -a�', PS71 i J March 9, 2015 Commissioner Cathy Foerster Alaska Oil and Gas Conservation Commission 333 West 7th Avenue Anchorage, AK 99501 Re: Pilgrim Hot Springs Geothermal Wells Docket No: OTH-14-019 Dear Commissioner Foerster: '=/A S KA � ENERGY AUTHORITY The Alaska Oil and Gas Conservation Commission (AOGCC) has requested that the Alaska Department of Commerce, Community, and Economic Development (DCCED) submit a plan to suspend or plug and abandon six geothermal wells: Pilgrim Springs I - 5 and Mary's Igloo 1. The Alaska Energy Authority (AEA) is working on behalf of DCCED to develop a plan for these wells in compliance with 20 AAC 25.105 and 20 AAC 25,112. Alan Baldivieso, AEA geothermal program manager, has consulted with Patricia Bettis and Guy Schwartz at AOGCC to gather infanmation and outline the steps required to plug and abandon all six wells. Alan has also contacted representatives of local landowners to confirm this is the preferred outcome. Based on these conversations and recommendations from AOGCC staff, AEA proposes to solicit bids through AEA's procurement process and select a contractor to perform the work; submit applications for sundry approval for the six wells to AOGCC; plug the wells according to the accepted plan with work estimated to be completed by September 30, 2015. 1 understand AOGCC staff has voiced support with the proposed course of action. Please let me know if you require additional information. Sii - rely, C -Ikl Sa -a isher-Goad Executive Director cc: Fred Parady, DCCED Acting Commissioner 813 WrsI Nonhern LLghts Bc,,devard Anchorage, Alaska 99503 T907 771 3000 Toll Free (Alaska Only; 888 300 8534 F 907 771,3044 Transmittal letter to be sent to: Chris Hladick, Commissioner Alaska Department of Commerce, Community, and Economic Development P.O. Box 110800 Juneau, AK 99811-0800 Wayne E. Westberg, President M -W Drilling, Inc. PO Box 110389 Anchorage, AK 99511 Cc: Alan P. Baldivieso, Geothermal Program Manager Alaska Energy Authority 813 West Northern Lights Blvd. Anchorage, AK 99503 Bettis, Patricia K (DOA) T lb / a-0 - 2:7Y From: Bettis, Patricia K (DOA) Sent: Monday, June 15, 2015 1:38 PM To: 'Alan P. Baldivieso' Cc: Guhl, Meredith D (DOA); Colombie, Jody J (DOA) Subject: Pilgrim Springs 1-5 and Mary's Igloo 1 Good afternoon Alan, The AOGCC has not received any sundry applications for the plugging and abandonment of the Pilgrim Springs 1-5 and Mary's Igloo 1 wells. Does AEA plan to submit those application in the near future? Thank you, Patricia Patricia Bettis Senior Petroleum Geologist Alaska Oil and Gas Conservation Commission 333 West 7'h Avenue Anchorage, AK 99501 Tel: (907) 793-1238 S WOE,) j u CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, contains information from the Alaska Oil and Gas Conservation Commission (AOGCC), State of Alaska and is for the sole use of the intended recipient(s). It may contain confidential and/or privileged information. The unauthorized review, use or disclosure of such information may violate state or federal law. If you are an unintended recipient of this e-mail, please delete it, without first saving or forwarding it, and, so that the AOGCC is aware of the mistake in sending it to you, contact Patricia Bettis at (907) 793-1238 or patricia.bettis@alaska.gov. alaska.gov. Bettis, Patricia K (DOA) �i� J(M— a -7y From: Alan P. Baldivieso <ABaldivieso@aidea.org> Sent: Monday, June 15, 2015 1:57 PM To: Bettis, Patricia K (DOA) Cc: Guhl, Meredith D (DOA); Colombie, Jody J (DOA) Subject: RE: Pilgrim Springs 1-5 and Mary's Igloo 1 Hi Patricia, During our earlier conversations, Guy had indicated that the applications for sundry approvals should be submitted by the contractor selected to perform the work. I just spoke with the contractor—MW Drilling—who indicated that he intends to submit the applications later this week. I understand that Wayne Westberg from MW Drilling has been in touch with Guy to clarify expectations for the applications. Best, Alan Baldivieso Program Manager Alaska Energy Authority (907) 771-3027 From: Bettis, Patricia K (DOA) [mailto:patricia.bettis@alaska.gov] Sent: Monday, June 15, 2015 1:38 PM To: Alan P. Baldivieso Cc: Guhl, Meredith D (DOA); Colombie, Jody J (DOA) Subject: Pilgrim Springs 1-5 and Mary's Igloo 1 Good afternoon Alan, SCANNED �' I..I N; 2, 62 M The AOGCC has not received any sundry applications for the plugging and abandonment of the Pilgrim Springs 1-5 and Mary's Igloo 1 wells. Does AEA plan to submit those application in the near future? Thank you, Patricia Patricia Bettis Senior Petroleum Geologist Alaska Oil and Gas Conservation Commission 333 West 7th Avenue Anchorage, AK 99501 Tel: (907) 793-1238 CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, contains information from the Alaska Oil and Gas Conservation Commission (AOGCC), State of Alaska and is for the sole use of the intended recipient(s). It may contain confidential and/or privileged information. The unauthorized review, use or disclosure of such information may violate state or federal law. If you are an unintended recipient of this e-mail, please delete it, without first saving or forwarding it, and, so that the AOGCC is aware of the mistake in sending it to you, contact Patricia Bettis at (907) 793-1238 or patricia.bettis@alaska.gov. Guhl, Meredith D (DOA) From: Bettis, Patricia K (DOA) Sent: Tuesday, March 03, 2015 1: To: Guhl, Meredith D (DOA) Cc: Schwartz, Guy L (DOA) Subject: FW: ACEP Reconnaissance Attachments: AppD_wellhead repairs.pdf Meredith, �o0-a7q �2 sq(a 3 51 PM Trip Report Pilgrim Springs Geothermal Wells Dated 2010 Per our discussion, please put a copy of the Wellhead Repair Report into Laserfiche Well History Folder for each of the following wells: Pilgrim Springs -1 (PTD 179-079) Pilgrim Springs -2 (PTD 179-085) Prim Sprin�(PTD 179-090) Pil rim Sorin s-4 PTD 1-jW-')7AII Pilgrim Springs -5 (PTD 100-275) Mary's Igloo -1 (PTD 100-276). SCANNED MAR 4 4 2015 Please also place a reference in RBDMS for each PTD that the report was received March 3, 2015. Thanks, Patricia From: Alan P. Baldivieso [mailto:ABaIdiviesoCcbaidea. org] Sent: Tuesday, March 03, 2015 1:00 PM To: Bettis, Patricia K (DOA); Schwartz, Guy L (DOA) Subject: RE: ACEP Reconnaissance Trip Report Pilgrim Springs Geothermal Wells Dated 2010 Thank you, Patricia. I spoke with Chris and he sent the attached report detailing the repairs that the University had done to some of the wellheads. Based on the conversation I had with Guy this morning, the application for sundry approvals will need to include specifics from the contractor that is ultimately selected to perform the work. I have identified several contractors that are familiar with the Pilgrim Hot Springs wells, but will need to accept bids through our procurement process prior to awarding the contract. I anticipate that the earliest the work can begin will be in July, although the road to the site may be clear of snow earlier than usual this year. I will specify that the work be completed by Sept 30, 2015. Is this approach to plugging and abandoning the 6 wells acceptable? Thank you, Alan Baldivieso Program Manager Geothermal, Hydrokinetic, Emerging Energy Technologies Alaska Energy Authority (907) 771-3027 From: Bettis, Patricia K (DOA) [mailto:patricia.bettis@alaska.gov] Sent: Tuesday, March 03, 2015 11:51 AM To: Schwartz, Guy L (DOA) Cc: Alan P. Baldivieso Subject: ACEP Reconnaissance Trip Report Pilgrim Springs Geothermal Wells Dated 2010 Guy and Alan, This report may be of use to you. UAF may have worked on some of the wells. Christopher Pike may be able to provide you with that information. His telephone number is (907) 272-1522; cell is (907) 888-3850. Regards, Patricia Patricia Bettis Senior Petroleum Geologist Alaska Oil and Gas Conservation Commission 333 West 7th Avenue Anchorage, AK 99501 Tel: (907) 793-1238 CONFIDENTIALITY NOTICE. This e-mail message, including any attachments, contains information from the Alaska Oil and Gas Conservation Commission (AOGCC), State of Alaska and is for the sole use of the intended recipient(s). It may contain confidential and/or privileged information. The unauthorized review, use or disclosure of such information may violate state or federal law. If you are an unintended recipient of this e-mail, please delete it, without first saving or forwarding it, and, so that the AOGCC is aware of the mistake in sending it to you, contact Patricia Bettis at (907) 793-1238 or patricia.bettis@alaska.gov. Bettis, Patricia K (DOA) ?/Y> /00 - o -y From: Mattson, Linda J (CED) Sent: Wednesday, December 10, 2014 9:05 AM To: Bettis, Patricia K (DOA) Cc: Fishergoad, Sara L (AIDEA); Skaling, Sean M (AIDEA); Parady, Fred E (CED) Subject: Signed Letter from Acting Commissioner Fred Parady Attachments: 12.08.14 Patricia Bettis Pilgrim Springs Letter.pdf Good Morning Ms. Bettis, Attached you will find a copy of a letter regarding the Pilgrim Springs Geothermal Wells issue that has been signed by Acting Commissioner Fred Parady. The original is in the mail to you. Please feel free to contact us at 465-2500 if you have any further questions. Cordially, Linda Mattson SCANNED DEC 10 2014 Executive Secretary Office of the Commissioner Department of Commerce, Community and Economic Development THE STATE Department of Commerce, Community, °fALAK;A and Economic Development S OFFICE OF THE COMMISSIONER GOVERNOR BILL WALKER P.O. Box 110800 Juneau. Alpsku 99811 •0800 Main: 907.465.2500 December 8, 2014 Ms. Patricia Bettis Senior Petroleum Geologist Alaska Oil and Gas Conservation Commission 333 West Seventh Avenue Anchorage, AK 99501 Dear Ms. Bettis: Programs fax: 907 465.5442 As you know from our conversation last week, DCCED has been working diligently to respond to your letter of September 12" regarding the Pilgrim Springs Geothermal Wells issue, Docket No: OTH-14-019. We have gathered substantial historical information and believe a proposed plan for the wells with the current project proponents is the solution although it remains unclear as to the specifics of DCCED's current responsibility and best path forward. Any action regarding the wells for which DCCED is listed as the operator appears to require coordination with the land owners Unataaq and Mary's Igloo Native Corporation. Regardless, pending completion of this research and sorting out these responsibilities, we would like to request a 60 day extension. We understand that ACEP has been or will be in contact with you regarding the four wells for which ACEP is the operator of record. Please feel free to contact me at any time regarding this matter. Sincerely, Fred Parady Acting Commissioner cc: Sara Fisher -Goad, Executive Director, Alaska Energy Authority Sean Skaling, Program Development and Project Evaluation Director, Alaska Energy Authority Bettis, Patricia K (DOA) ill-� �l /Clo - From: Sara Fisher -Goad <SFisherGoad@aidea.org> Sent: Thursday, December 04, 2014 4:48 PM To: Bettis, Patricia K (DOA) Cc: Parady, Fred E (CED); Bittner, Jon S (CED); Skaling, Sean M (AIDEA); Baldivieso, Alan P (AIDEA) Subject: RE: Pilgrim Springs Attachments: AOGCC-correspondence.pdf Patricia —I've attached some scanned correspondence relating to the Pilgrim Hot Springs wells listing Commerce as the operator. The 2009 AOGCC correspondence with AEA regarding the wells is attached. Also attached is a letter from AOGCC to BSNC regarding wells 197078 and 179085. Could you please confirm who AOGCC considers responsible for the 6 wells that have Commerce listed as the operator? I understand UAF and Unaatuq will be responding to AOGCC's September 12, 2014 letter and addressing the 4 wells listing UAF as the operator of record. Sara SCANNED D E C 10 2014 Sara Fisher -Goad Executive Director Alaska Energy Authority 907-771-3012 (Office) 907-301-0103 (Cell) From: Bettis, Patricia K (DOA) [mailto:patricia.bettis@alaska.gov] Sent: Wednesday, December 03, 2014 2:01 PM To: Sara Fisher -Goad Cc: Parady, Fred E (CED); Jon Bittner Subject: Pilgrim Springs Sa ra, The AOGCC records show the Division of Energy & Power as the operator of record for Pilgrim Springs -1, Pilgrim Springs - 2, Pilgrim Springs -3, Pilgrim Springs -4, Pilgrim Springs -5 and Mary's Igloo -1 geothermal wells. Hence, AOGCC's September 12, 2014 Pilgrim Springs Geothermal Wells letter was sent to the Alaska Department of Commerce, Community, and Economic Development. Patricia Bettis Senior Petroleum Geologist Alaska Oil and Gas Conservation Commission 333 West 7th Avenue Anchorage, AK 99501 Tel: (907) 793-1238 CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, contains information from the Alaska Oil and Gas Conservation Commission (AOGCC), State of Alaska and is for the sole use of the intended recipient(s). It may contain confidential and/or privileged information. The unauthorized review, use or disclosure of such information may violate state or federal law. If you are an unintended recipient of this e-mail, please delete it, without first saving or forwarding it, and, so that the AOGCC is aware of the mistake in sending it to you, contact Patricia Bettis at (907) 793-1238 or patricia.bettis@alaska.gov. SEAN PARNELL, GOVERNOR LiiASK& OIL AND GAS - 333 W. 7th AVENUE, SUITE 100 CONSERVATION COMMISSION ANCHORAGE, ALASKA 99501.3539 PHONE (907) 279-1433 FAX (907) 276-7542 November 18, 2009 CERTIFIED MAIL RETURN RECEIPT REQUESTED 7009 2250 0004 3911 4986 Irene Anderson Bering Straits Native Corporation PO Box 1008a�i 110 Front Street, Suite 300 Nome, Alaska 99762 Re: Wells Pilgrim Spring 1 (PTD 179078), Pilgrim Spring 2 (PTD 179085) Dear Ms. Anderson: In October, 1979 the Alaska Oil and Gas Conservation Commission (AOGCC or Commission) issued permits to drill the subject wells. The Commission is currently reviewing records for the purpose of identifying Alaska wells that have not been properly plugged and abandoned, and which thus may constitute safety or environmental hazards. Our records reveal that the wells identified above require remedial action to bring them into com- pliance with current Commission regulations, This remedial work will include cementing the wells in accordance with 20 AAC 25, Article 2. AOGCC is contacting you to request assis- tance in identifying current property ownership so that the required action can be taken. The Commission is also sending copies of this correspondence to the Catholic Church Fairbanks Diocese, to the entity identified as Mary's Igloo, and to Mr. Steve Haagenson, Executive Director of the Alaska Energy Authority, to make them aware of the potential hazards presented by these wells. It is our intention to have the responsible well owner properly plug and abandon the wells. Should the owner fail to do so, then AOGCC intends to contract to plug and abandon the wells, reserving the right to hold responsible parties financially accountable for costs incurred. If you have questions regarding this finding, please contact Mr. Winton Aubert, Senior Engineer, at 907-793-1231 or winton.aubert@aJ&ska.gov. Sincerely, Cathy P. erster Commiss oner cc: Catholic Church Fairbanks Diocese Steve Haagenson, SOA, Dept of Commerce 1y 1E)Ek imeni YV and Export Authority October 14, 2009 Ms. Cathy P. Foerster, Commissioner Alaska Oil and Gas Conservation Commission 333 W. 7t" Avenue, Suite 100 Anchorage, AK 99501-3539 Re: Status of Oil and Gas Wells Dear Ms. Foerster ALASKA ENERGY AUTHORITY RECEIVED OCT 1 6 2009 Abda Di & GM Cow Cittl ily inion Antherep I'm writing in response to your September 30, 2009, letter wherein you requested a letter to verify suspended. long-term shut-in and observation wells Subsequent to receiving the letter, AEA's Mike Harper conferred with Winton Aubert of your office. To the best of our knowledge, there has been no significant activity at Pilgrim Hot Springs since 1982 Our brief research shows that the only interest has been potential development of the geothermal hot springs in the area However, most significant is the ownership of this parcel containing the wells. It is our understanding that Pilgrim Hot Springs is owned by the Catholic Church for surface estate while the local Native Corporation, Mary's Igloo, is subsurface owner. If you desire further information about land issues you may wish to contact Irene Anderson of Bering Straits Native Corporation in Nome There has been talk of further research and exploration with the Mary's Igloo group possibly partnering with Alaska Center for Energy and Power at UAF. There is data that one can easily attain through the internet, but I have included two reports that will provide some background. If you desire further information please feel free to contact David Lockard, PE with our office at (907) 771-3062. Sincerely, A,LnAS�KA ENERGY AUTHORITY W. r. V -a - Steve Haagenson Executive Director Attachments: 1982 Stanford University Report AEA 2007 Feasibility Report cc Tab Ballantine, Department of Law Irene Anderson, Bering Straits Native Corporation Gwen Holdmann, Alaska Center for Energy and Power David Lockard, AEA 813 West Northern Lights Boulevard • Anchorage, Alaska 99503-2495 www.aidea.org • 907/771-3000 0 FAX 907/771-3044 1 Toll Free (Alaska Only) 888/300-8534 • www.akenergyauthority.org ALA-SEEL GILL AND GAS CG &TRERVA'E`)l1ON COMUSSIOICT September 30, 2009 CERTIFIED MAIL RETURN RECEIPT REQUESTED 7005 1160 0001 5753 9158 k-1 -% — 0-1 -,�— SEAN PARNELL, GOVERNOR i 333 W. 7th AVENUE. SUITE 100 ANCHORAGE, ALASKA 99501-3539 PHONE (907)279-1433 FAX (907)276-7542 Steve Hagenson AEA Executive Director 813 W. Northern Lights Blvd. Anchorage, AK 99503 Re: Failure to Respond to Request for Information (20 AAC 25.300) Status of Oil and Gas Wells Dear Mr. Hagenson: Under 20 AAC 25.300 you are required to provide information requested by the Alaska Oil and Gas Conservation Commission (Commission). On January 28, 2009 the Commission requested verification of suspended, long-term shut-in and observation wells. To date you have provided no response to the Commission. This correspondence constitutes the Commission's final request for you to verify the wells as suspended, long-term shut-in or observation wells. If the requested information has not been received by the Commission by the close of business on December 1, 2009, you will be considered in violation of 20 AAC 25.300 and the Commission will take such action as it deems appropriate including, but not limited to, initiation of a public hearing, initiation of an enforcement action, and imposition of penalties as authorized under AS 31.05.150. If you have any questions regarding this request, please contact Winton Aubert at 907.793.1231 or winton.aubertnaalaska.gov. Sincerely, In CatjPoerster Commissioner Attachment cc: Tab Ballantine Department of Law r -t � SARAH PALIN, GOVERNOR L ALASKA OIL AND GAS J 333 W 7th AVENUE, SUITE 700 ANCHORAGE. ALASKA 99501-3539 COMUSSION PHONE (907)279.1433 January 28; 2009 FAX (907) 276-7542 CERTIFIED MAIL RETURN RECEIPT REQUESTED 7005 1820 0001 2499 6057 Steve Hagenson AEA Executive Director 813 W. Northern lights Anchorage AK 9950; 1q(ANNeD IZe: Notice of 1Zevised Suspended Wells Regulations and Request for Verification of Suspended and Shut -In Well hil'ormation Dear Mr. Hagenson: Enclosed are the Alaska Oil and Gas Conservation Commission's revised regulations regarding suspended wells (i. e., 20 AAC 25.110). Also enclosed is a list of suspended and long-term shut-in wells operated by the Alaska Energy Authority or your predecessor, the Division of Energy and Power Development. For each list, please verify the information for each well and provide any corrections by April 1, 2009. Location inspections required under 20 AAC 25.110 should be coordinated with Jim Regg at 907-793-1236 or jim.regg@alaska.gov. If you have any questions regarding this notice, please contact Tom Maunder at 907-793- 1250 or tom.maunder@alaska.gov. Sincerely, d4o�_ Cathy . Foerster Commissioner Enclosures Bettis, Patricia K (DOA) SFJ /W _any From: Sara Fisher -Goad <SFisherGoad@aidea.org> Sent: Wednesday, December 03, 2014 2:12 PM To: Bettis, Patricia K (DOA) Cc: Parady, Fred E (CED); Bittner, Jon S (CED) Subject: RE: Pilgrim Springs Thank you. Although we have no one on staff who was here during that time, it does appear with some of the documents we uncovered that it was a division in Department of Commerce and not a part of AEA or old APA. Fred — regardless of that issue, we can still help get this issue addressed. Sa ra From: Bettis, Patricia K (DOA) [mailto:patricia.bettis@alaska.gov] Sent: Wednesday, December 03, 2014 2:01 PM To: Sara Fisher -Goad Cc: Parady, Fred E (CED); Jon Bittner Subject: Pilgrim Springs Sara, NEO DEC 10 2014 The AOGCC records show the Division of Energy & Power as the operator of record for Pilgrim Springs -1, Pilgrim Springs - 2, Pilgrim Springs -3, Pilgrim Springs -4, Pilgrim Springs -5 and Mary's Igloo -1 geothermal wells. Hence, AOGCC's September 12, 2014 Pilgrim Springs Geothermal Wells letter was sent to the Alaska Department of Commerce, Community, and Economic Development. Patricia Bettis Senior Petroleum Geologist Alaska Oil and Gas Conservation Commission 333 West 7th Avenue Anchorage, AK 99501 Tel: (907) 793-1238 CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, contains information from the Alaska Oil and Gas Conservation Commission (AOGCC), State of Alaska and is for the sole use of the intended recipient(s). It may contain confidential and/or privileged information. The unauthorized review, use or disclosure of such information may violate state or federal law. If you are an unintended recipient of this e-mail, please delete it, without first saving or forwarding it, and, so that the AOGCC is aware of the mistake in sending it to you, contact Patricia Bettis at (907) 793-1238 or patricia.bettis@alaska.gov. Bettis, Patricia K (DOA)loo — ),7y From: Bettis, Patricia K (DOA) Sent: Wednesday, December 03, 2014 2:01 PM To: Fishergoad, Sara L (AIDEA) Cc: Parady, Fred E (CED); Bittner, Jon S (CED) Subject: Pilgrim Springs SCANNED D E C 10 2014 Sara, The AOGCC records show the Division of Energy & Power as the operator of record for Pilgrim Springs -1, Pilgrim Springs - 2, Pilgrim Springs -3, Pilgrim Springs -4, Pilgrim Springs -5 and Mary's Igloo -1 geothermal wells. Hence, AOGCC's September 12, 2014 Pilgrim Springs Geothermal Wells letter was sent to the Alaska Department of Commerce, Community, and Economic Development. Patricia Bettis Senior Petroleum Geologist Alaska Oil and Gas Conservation Commission 333 West 7th Avenue Anchorage, AK 99501 Tel: (907) 793-1238 CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, contains information from the Alaska Oil and Gas Conservation Commission (AOGCC), State of Alaska and is for the sole use of the intended recipient(s). It may contain confidential and/or privileged information. The unauthorized review, use or disclosure of such information may violate state or federal law. If you are an unintended recipient of this e-mail, please delete it, without first saving or forwarding it, and, so that the AOGCC is aware of the mistake in sending it to you, contact Patricia Bettis at (907) 793-1238 or patricia.bettis@alaska.gov. Bettis, Patricia K (DOA) ? i 1� Jpd — From: Sara Fisher -Goad <SFisherGoad@aidea.org> Sent: Wednesday, December 03, 2014 11:41 AM To: Parady, Fred E (CED) ANIN1E D DEC 10 2014 Cc: Bettis, Patricia K (DOA); Bittner, Jon S (CED) Subject: RE: Pilgrim Springs Geothermal Wells I have our geothermal project manager looking into this and we have a call into Gwen at UAF. The years associated with the drilling from "Division of Energy and Power" is probably old AEA nea APA (Alaska Power Authority). This is an interesting puzzle and I was not aware of this deadline or requirement prior to your email earlier today. It will take us at least a day to close the loop with UAF and come up with a plan, we are researching our library on old documentation. I agree with you, we need to apply for an extension. Patricia — do you know why this was not sent to AEA directly? Do the original documents from 1979 and 1982 mention Alaska Power Authority (I think the name change to AEA happened in 1990)? Sara PS — congratulations on the Acting Commissioner assignment. Sara Fisher -Goad Executive Director Alaska Energy Authority 907-771-3012 (Office) 907-301-0103 (Cell) From: Parady, Fred E (CED) [mailto:fred.parady@alaska.gov] Sent: Wednesday, December 03, 2014 9:36 AM To: Sara Fisher -Goad Cc: Bettis, Patricia K (DOA); Jon Bittner Subject: FW: Pilgrim Springs Geothermal Wells Sa ra Attached is a copy of a letter we received regarding DCCED well closure obligations from the Pilgrim Springs Geothermal project from 1979-1982. The operator is listed as DCCED Division of Energy and Power. Did that migrate into AEA, and can you help me run this to ground? We need to come up with an abandonment plan or plan of suspension. We also likely need to apply for an extension. We are working against a 12/15/14 deadline. Thanks for your help. Fred From: Bettis, Patricia K (DOA) Sent: Wednesday, December 03, 2014 9:21 AM To: Parady, Fred E (CED) Cc: Schwartz, Guy L (DOA) Subject: Pilgrim Springs Geothermal Wells Good morning Acting Commissioner Parady, I checked the USPS certified return receipt (green card) and the Alaska Department of Commerce, Community, and Economic Development received the Pilgrim Springs Geothermal Wells letter dated September 12, 2014 on September 15, 2014. I attached the wellbore schematics for those wells operated by the Division of Energy & Power for which the AOGCC has a record. This includes Mary's Igloo -1, PS -3, PS -4 and PS -5. Please note that these are old wellbore schematics contained in a 1983 Woodward -Clyde Consultants report entitled "Geothermal Energy Development at Pilgrim Springs, Alaska, Phase 11: Results of Drilling, Testing and Resource Confirmation" and may not reflect the current conditions of the wells. If you have any further questions, please do not hesitate to call or e-mail me. Regards, Patricia Patricia Bettis Senior Petroleum Geologist Alaska Oil and Gas Conservation Commission 333 West 7th Avenue Anchorage, AK 99501 Tel: (907) 793-1238 CONFIDENTIALITY NOTICE. This e-mail message, including any attachments, contains information from the Alaska Oil and Gas Conservation Commission (AOGCC), State of Alaska and is for the sole use of the intended recipient(s). It may contain confidential and/or privileged information. The unauthorized review, use or disclosure of such information may violate state or federal law. If you are an unintended recipient of this e-mail, please delete it, without first saving or forwarding it, and, so that the AOGCC is aware of the mistake in sending it to you, contact Patricia Bettis at (907) 793-1238 or patricia.bettis@alaska.gov. Bettis, Patricia K (DOA) +—I From: Parady, Fred E (CED) Sent: Wednesday, December 03, 2014 9:36 AM To: Fishergoad, Sara L (AIDEA) Cc: Bettis, Patricia K (DOA); Bittner, Jon S (CED) Subject: FW: Pilgrim Springs Geothermal Wells Attachments: MI-1.pdf; PS -3 Wellbore schematic.pdf; PS -4 Wellbore schematic.pdf; PS -5 Wellbore schematic.pdf; Pilgrim Springs Geothermal Wells.pdf Sa ra SCANNED DEC 10 2014 Attached is a copy of a letter we received regarding DCCED well closure obligations from the Pilgrim Springs Geothermal project from 1979-1982. The operator is listed as DCCED Division of Energy and Power. Did that migrate into AEA, and can you help me run this to ground? We need to come up with an abandonment plan or plan of suspension. We also likely need to apply for an extension. We are working against a 12/15/14 deadline. Thanks for your help. Fred From: Bettis, Patricia K (DOA) Sent: Wednesday, December 03, 2014 9:21 AM To: Parady, Fred E (CED) Cc: Schwartz, Guy L (DOA) Subject: Pilgrim Springs Geothermal Wells Good morning Acting Commissioner Parady, I checked the USPS certified return receipt (green card) and the Alaska Department of Commerce, Community, and Economic Development received the Pilgrim Springs Geothermal Wells letter dated September 12, 2014 on September 15, 2014. I attached the wellbore schematics for those wells operated by the Division of Energy & Power for which the AOGCC has a record. This includes Mary's Igloo -1, PS -3, PS -4 and PS -5. Please note that these are old wellbore schematics contained in a 1983 Woodward -Clyde Consultants report entitled "Geothermal Energy Development at Pilgrim Springs, Alaska, Phase 11: Results of Drilling, Testing and Resource Confirmation" and may not reflect the current conditions of the wells. If you have any further questions, please do not hesitate to call or e-mail me. Regards, Patricia Patricia Bettis Senior Petroleum Geologist Alaska Oil and Gas Conservation Commission 333 West 7th Avenue Anchorage, AK 99501 Tel: (907) 793-1238 CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, contains information from the Alaska Oil and Gas Conservation Commission (AOGCC), State of Alaska and is for the sole use of the intended recipient(s). It may contain confidential and/or privileged information. The unauthorized review, use or disclosure of such information may violate state or federal law. If you are an unintended recipient of this e-mail, please delete it, without first saving or forwarding it, and, so that the AOGCC is aware of the mistake in sending it to you, contact Patricia Bettis at (907) 793-1238 or patricia.bettis@alaska.gov. THE STATE oALASKA (;0VERNOk SEAN PAR\FAA September 12, 2014 CERTIFIED MAIL - RI?TI1RN RECEIPT REQUF.sTI:D 7012 3050 0001 4812 6808 (Unaatuq) 7012 3050 00014812 6815 (DCED) 7012 3050 0001 4812 6822 (UAF) Matt Ganley, Resources and External Affairs Unaatuq, LLC c/o Bering Straits Native Corporation P.O. Box 1008 Nnmc. AK 'Y!"62 Alaska Oil and Gas (conservation Commission Ms. Susan K. Bell, Cnmmissioner Alaska Department of Commerce, Community, and Economic Development P.O. Box 110800 juneau,AK 99811-0800 Gwen Holdnlann, Director UAF Alaska Center for F,nergy & Power P.O. Box 755910 Fairbanks, AK 99775-5910 Re: Pilgrim Springs Geothermal Wells Docket No: 0TH -14-019 Dear Mr. Ganlev, Ms. Bell and Ms. Holdmann: 333 Wei! Se ern11: A -E -Cut Ancnoroge. Alaska 95501 3572 !n r 907 179. �3'= As operators or landowner of record, you are advised that the ten geothermal wells drilled in the area of Pilgrim Springs, Alaska (see attached list) must either be plugged and abandoned in compliance with 20 AAC 25.105 and 20 AAC 25.112 or suspended under 20 AAC 25.110. Alaska Oil and Gas Conservation AOGCC regulations can be found at the following internet address: hittp-:fjdoa.alask.gQ_v/QgcjR_u..lat#.onslReglgdex.htmi. A Sundry application form (Form 10-403) for the submittal of a plan of abandonment or a plan of suspension for a well to the AOGCC. can he found at- http:jjdoa.alaska.govjogc/forms/forms.htmi. Please note that each application for Sundry Approval must include a well schematic diagram showing the well's current condition and a well schematic diagram showing proposed downhole well design changes to comply with applicable regulations for plug and abandonment or suspension. Pilgrim Springs Geothermal Wells September 12, 2014 Page 2 of 2 If the AOGCC does not receive an acceptable plan and schedule for all ten wells within ninety (90) days of receipt of this letter, the AOGCC will notice a public hearing to determine whether remedial action is necessary with regard to the wells and which entity will bear responsibility for compliance. The applicable University of Alaska, Fairbanks Alaska Center for Energy & Power's (UAF) lease will be expiring soon relative to the PS# 12-1, I'S 12-2, PS 12-3 and PS 13-1 wells. tinder 20 AAC 25.105, all permitted wells on a property must be properly abandoned before expiration of the operator's rights. Upon expiration of the lease, if these wells are not plugged and abandoned to the satisfaction of the AOGCC, UAF's bond will be forfeited. Forfeiture of the bond will not relieve UAF of responsibility for plugging and abandoning of the wells under AS 31.05. If Unaatuq, LLC desires to take over operatorship of these four wells, a Designation of Operator Form (Form 10411) must be submitted to and approved by the AOGCC, as provided under 20 AAC 25.020 in addition to filing the bond required by 20 AAC 25.025. Please call Ms. Patricia Bettis at (907) 793-1238 if you have question concerning this matter. Sincerely, e4 /10 Cathy P Foerster Chair, Commissioner Attachment M Kit Duke, Associate Vice President University of Alaska Facilities and Land Management 1815 Bragaw St., Ste. 101 Anchorage, AK 99508 Larry Hartig, Commissioner Department of Environmental Conservation P.O. Box 111800 Juneau, AK 99811-1800 VV%, F C, ` PILGRIM SPRINGS GEOTHERMAL WELLS *SOA, Department of Commerce and Economic Development, Division of Energy and Power Attachment 1 DATE TOTAL DEPTH WELL NAME PTD No. OPERATOR OF RECORD Location DRILLED (feet) STATUS Pilgrim Springs -1 179-078 SOA, Division of Energy & Power* 36, T4S. R31W, KRM 1979 150 Shut-in Pilgrim Springs -2 2/9-08S SOA, Division of Energy & Power' 03, TSS, R31W, KRM 1979 ISO Shut-in Pilgrim Springs -3 179 090 SOA, Division of Energy & Power* 03, TSS, R31W, KRM 1982 260 Shut-in Pilgrim Springs -4 100-274 SOA, Division of Energy & Power* 03, TSS, R31W, KRM 1982 881, Shut-in Pilgrim Springs -5 100-275 SOA, Division of Energy & Power* 03, T55, R31W, KRM 1982 1001 Shut-in Mary's Igloo -1 100-276 SOA, Division of Energy & Power* 03, TSS, R31W, KRM 1982 307 Shut-in PS 12-1 212-077 UAF Alaska Center for Energy & Power 36, T4S, R31W, KRM 2012 1000 Suspended PS 12-2 212-109 UAF Alaska Center for Energy & Power 36, T4S, R31W, KRM 2012 1294 Suspended PS 12-3 212-126 UAF Alaska Center for Energy & Power 36, T4S, R31W, KRM 2012 1183 Suspended PS 13-1 213-102 UAF Alaska Center for Energy & Power 36, T4S, R31 W, KRM 2013 1036 Suspended *SOA, Department of Commerce and Economic Development, Division of Energy and Power Attachment 1 2 -inch side ports with 2 -inch valves 10 -inch blind flange 410 -inch master gate valve G. L. n, V ftft 16 -inch casing in 20 -inch zY auger hole Cement r4 58 ft 10 -inch casing in 14-% inch hole --93— 6 -inch casing in 9-719 inch hole 167.5 ft 3- X 5 -inch concentric reducer welded on 3 -inch pipe overlap 12 ft II I --=0-3-inch slotted casing II Total length 105 ft 1 T.D. drilled 260 ft Project No. Pilgrim Springs 15267A I CASING PROFILE OF WELL PS -3 Figure VADOdward-Ctyde Consuftants 6 L J 10 -inch master valve - 2 -inch outlets with valves G. L. *It ° 19 ft ..: ,s •0 86.5 ft '• Ge Cement '• Op ♦a ID 187.4 ft 5 ft drill pipe, 3 drill collars, 7-7/8 in, stabilizer, sub float & bit for total length of 70.2 ft of steel left in hole TO drilled 881 ft �_. 10 -inch blind flange with 1 -inch nipple for flow ... • •... ��— 19 ft: 16 inch casing ,e in 20 -inch hole 86.52 ft: 10 -inch casing os in 14-% inch hole rr O� •I �o „*_ 187.42 ft:8-inch casing 6 in 9 -SIB inch hole 0 G� e, Open hole 97/8 inch to 520 ft; 7?/B inch below Lost drill stem in open hole 'roject No. 15267A I Pilgrim Springs CASING PROFILE OF WELL PS -4 Figure Woof want-Ctyde Consuttants 7 10 -inch blind flange ---�1- 10 -inch master gate valve----{�- G.L. 11 it 42 it Cement 178 it 588 it 981 it T.D. drilled 1001 it • 2 -inch side ports with 2 -inch valves - 2 each d 16 -inch casing in 20 -inch auger hole Ob o� 4 10 -inch casing in 6a 14-% inch hole ca b .a G ya Og60 8 -inch casing in 0,1 14-% inch hole Gb 0 VC, Oo,0 Q e °i Overlap 10 it n be 6- X 7 -inch concentric Dna reducer -� 6 -inch casing in 7.71$ inch hole 0 •s�ly 20 it cement at bottom of 6 -inch casing. 3- X 5 -inch concentric reducer o-' 441 ft: 3 -inch slotted casing Project No. 15267A Pilgrim Springs Figure CASING PROFILE OF WELL PS -5 8 Woodyard -Clyde Cormukants 10 -inch blind flange 10 -inch master gate valve G. L. .poi !o to�s,e o, pV . Ov�o •Q O Y • L � 1 � 20 ft a%•oi 80 ft Cement 151 ft 232 ft r t� T.D. 307 ft 6 -inch in 14-% inch hole 1 ' d 3 -inch slotted casing 84 ft l� 11 Project No. 15267A Pilgrim Springs Figure CASING PROFILE OF WELL MI -1 Wood"rd•CWe Cormgt i,. 9 2 -inch side ports with 2 -inch valves :� 'O•; :� 20 ft. 16 -inch in r;: � : •; �o• �ILL•0 20 -inch hole •• .is d� r 8 -inch in 141% inch hole 6 -inch in 14-% inch hole 1 ' d 3 -inch slotted casing 84 ft l� 11 Project No. 15267A Pilgrim Springs Figure CASING PROFILE OF WELL MI -1 Wood"rd•CWe Cormgt i,. 9 Bettis, Patricia K (DOA) P i� /QU - �?y From: Bettis, Patricia K (DOA) Sent: Wednesday, December 03, 2014 9:21 AM To: Parady, Fred E (CED) Cc: Schwartz, Guy L (DOA) Subject: Pilgrim Springs Geothermal Wells Attachments: MI-l.pdf; PS -3 Wellbore schematic.pdf; PS -4 Wellbore schematic.pdf; PS -5 Wellbore schematic.pdf SCANNED D E C 10 2014 Good morning Acting Commissioner Parady, I checked the USPS certified return receipt (green card) and the Alaska Department of Commerce, Community, and Economic Development received the Pilgrim Springs Geothermal Wells letter dated September 12, 2014 on September 15, 2014. I attached the wellbore schematics for those wells operated by the Division of Energy & Power for which the AOGCC has a record. This includes Mary's Igloo -1, PS -3, PS -4 and PS -5. Please note that these are old wellbore schematics contained in a 1983 Woodward -Clyde Consultants report entitled "Geothermal Energy Development at Pilgrim Springs, Alaska, Phase 11: Results of Drilling, Testing and Resource Confirmation" and may not reflect the current conditions of the wells. If you have any further questions, please do not hesitate to call or e-mail me. Regards, Patricia Patricia Bettis Senior Petroleum Geologist Alaska Oil and Gas Conservation Commission 333 West 7th Avenue Anchorage, AK 99501 Tel: (907) 793-1238 CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, contains information from the Alaska Oil and Gas Conservation Commission (AOGCC), State of Alaska and is for the sole use of the intended recipient(s). It may contain confidential and/or privileged information. The unauthorized review, use or disclosure of such information may violate state or federal law. If you are an unintended recipient of this e-mail, please delete it, without first saving or forwarding it, and, so that the AOGCC is aware of the mistake in sending it to you, contact Patricia Bettis at (907) 793-1238 or patricia.bettis@alaska.gov. 2 -inch side ports with 2 -inch valves G. L. 17 ftft Cement -- 58 ft —167.5 ft _ T.D. drilled 260 ft Project No. l Pilgrim Springs 15267A Woodward Clyde Cogs AaMs Q--- 10 -inch blind flange —0— 10winch master gate valve 16 -inch casing in 20 -inch auger hole 10 -inch casing in 14 A. inch hole .p-- 6 -inch casing in 9-7/8 inch hole 3- X 5 -inch concentric reducer welded on 3 -inch pipe overlap 12 ft .p -3 -inch slotted casing Total length 105 ft CASING PROFILE OF WELL PS -3I Figure 6 • 10 -inch master valve 2 -inch outlets with valves ` c G. L. e e• e. 19ft 86.5 ft Cement 187.4 ft 5 ft drill pipe, 3 drill collars, 7-7/8 in, stabilizer, sub float & bit for total length of 70.2 ft of steel left in hole TO drilled 881 ft .�� 10 -inch blind flange with 1 -inch nipple for flow �o --- 19 ft: 16 -inch casing �. in 20 -inch hole eao r,� ••�} — 86.52 ft: 10 -inch casing c ` in 14-% inch hole 187,42 ft:8-inch casing oa in 9.718 inch hole ce ..�_ Open hole 97/8 inch to 520 ft; 7-7/8 inch below Lost drill stem in open hole Project No. 15267A I Pilgrim Springs CASING PROFILE OF WELL PS -4 Figure Woodward -Clyde Consultants 7 10 -inch blind flange=---��- 10 -inch master gate valve--Ca- G.L. 11 ft 42 ft Cement 176 ft 586 ft 981 ft T.D. drilled 1001 ft 2 -inch side ports with 2 -inch valves - 2 each d 16 -inch casing in 20 -inch auger hole b� es o° -C'] 10 -inch casing in 66 14.% inch hole ea e cG b ,e Gs� cBGe &inch casing in Gp: 14-'K inch hole a a eo, G 0, Q .e °' •eOverlap 10 ft e ea 6- X 7 -inch concentric reducer •a* 6 -inch casing in 7.7,E inch hole V 20 ft cement at bottom of 6 -inch casing. 3- X 5 -inch concentric reducer 441 ft: 3 -inch slotted casing Project No. 15267A Pilgrim Springs Figure CASING PROFILE OF WELL PS -5 8 Ubodward-Clyde Consultants 10 -inch blind flange 10 -inch master gate valve G.L. ,o ,:opos• t 'a J , Ov•° •d� 20 ft fo o.•e► 80 ft Cement 151 ft 232 ft T.D. 307 ft l 2 -inch side ports with j 2 -inch valves 20 ft: 16 -inch in r�� •��e• 20 -inch hole �1 rd �s r i 8 -inch in 14:Y. inch hole I I ( ( —t0— 6 -inch in 14-% inch hole I I I ► 1 i 3 -inch slotted casing 84 ft Project No. 15267A Pilgrim Springs Figure CASING PROFILE OF WELL MI -1 V100dwalyd•Cly+de Consultants 9 %; �- THE STATE Alzskaa 0L, and zs tt }} Aar_-L.,*_1QFFrn/1-1 tom. <� .'i :,. GOVERNOR SEAN PARNELL September 12, 2014 CERTIFIED MAIL - RETURN RECEIPT REQUESTED 7012 3050 00014812 6808 (Unaatuq) 7012 3050 00014812 6815 (DCED) 7012 3050 00014812 6822 (UAF) 333 West Seventh Avenue Anchorage, Alaska 99501-3572 Main: 907.279.1433 Fax: 907.276.7542 Matt Ganley, Resources and External Affairs Unaatuq, LLC c/o Bering Straits Native Corporation SCWIM OCT 02 2014 P.O. Box 1008 Nome, AK 99762 Ms. Susan K. Bell, Commissioner Alaska Department of Commerce, Community, and Economic Development P.O. Box 110800 Juneau, AK 99811-0800 Gwen Holdmann, Director UAF Alaska Center for Energy & Power P.O. Box 755910 Fairbanks, AK 99775-5910 Re: Pilgrim Springs Geothermal Wells Docket No: OTH-14-019 Dear Mr. Ganley, Ms. Bell and Ms. Holdmann: As operators or landowner of record, you are advised that the ten geothermal wells drilled in the area of Pilgrim Springs, Alaska (see attached list) must either be plugged and abandoned in compliance with 20 AAC 25.105 and 20 AAC 25.112 or suspended under 20 AAC 25.110. Alaska Oil and Gas Conservation AOGCC regulations can be found at the following internet address: http://doa.alaska.govlogc/Regulations/Reglndex.html. A Sundry application form (Form 10-403) for the submittal of a plan of abandonment or a plan of suspension for a well to the AOGCC can be found at: httl2://doa.alaska.gov/ogcZforms/forms.html. Please note that each application for Sundry Approval must include a well schematic diagram showing the well's current condition and a well schematic diagram showing proposed downhole well design changes to comply with applicable regulations for plug and abandonment or suspension. Pilgrim Springs Geothermal Wells September 12, 2014 Page 2 of 2 If the AOGCC does not receive an acceptable plan and schedule for all ten wells within ninety (90) days of receipt of this letter, the AOGCC will notice a public hearing to determine whether remedial action is necessary with regard to the wells and which entity will bear responsibility for compliance. The applicable University of Alaska, Fairbanks Alaska Center for Energy & Power's (UAF) lease will be expiring soon relative to the PS# 12-1, PS 12-2, PS 12-3 and PS 13-1 wells. Under 20 AAC 25.105, all permitted wells on a property must be properly abandoned before expiration of the operator's rights. Upon expiration of the lease, if these wells are not plugged and abandoned to the satisfaction of the AOGCC, UAF's bond will be forfeited. Forfeiture of the bond will not relieve UAF of responsibility for plugging and abandoning of the wells under AS 31.05. If Unaatuq, LLC desires to take over operatorship of these four wells, a Designation of Operator Form (Form 10-411) must be submitted to and approved by the AOGCC, as provided under 20 AAC 25.020 in addition to filing the bond required by 20 AAC 25.025. Please call Ms. Patricia Bettis at (907) 793-1238 if you have question concerning this matter. Sincerely, P Cathy P Foerster Chair, Commissioner Attachment cc: Kit Duke, Associate Vice President University of Alaska Facilities and Land Management 1815 Bragaw St., Ste. 101 Anchorage, AK 99508 Larry Hartig, Commissioner Department of Environmental Conservation P.O. Box 111800 Juneau, AK 99811-1800 PILGRIM SPRINGS GEOTHERMAL WELLS WELL NAME PTD No. OPERATOR OF RECORD Location DATE TOTAL DEPTH STATUS DRILLED (feet) Pilgrim Springs -1 179-078 SOA, Division of Energy & Power* 36, T4S, R31W, KRM 1979 150 Shut-in Pilgrim Springs -2 179-085 SOA, Division of Energy & Power* 03, T5S, R31W, KRM 1979 150 Shut-in Pilgrim Springs -3 179-090 SOA, Division of Energy & Power* 03, T5S, R31W, KRM 1982 260 Shut-in Pilgrim Springs -4 100-274 SOA, Division of Energy & Power* 03, T5S, R31W, KRM 1982 881 Shut-in Pilgrim Springs -5 100-275 SOA, Division of Energy & Power* 03, T5S, R31W, KRM 1982 1001 Shut-in Mary's Igloo -1 100-276 SOA, Division of Energy & Power* 03, T5S, R31W, KRM 1982 307 Shut-in PS 12-1 212-077 UAF Alaska Center for Energy & Power 36, T4S, R31W, KRM 2012 1000 Suspended PS 12-2 212-109 UAF Alaska Center for Energy & Power 36, T4S, R31W, KRM 2012 1294 Suspended PS 12-3 212-126 UAF Alaska Center for Energy & Power 36, T4S, R31W, KRM 2012 1183 Suspended PS 13-1 213-102 UAF Alaska Center for Energy & Power 36, T4S, R31W, KRM 2013 1036 Suspended *SOA, Department of Commerce and Economic Development, Division of Energy and Power Attachment 1 Page 1 of 1 0 roo Z7q i Aubert, Winton G (DOA) From: Gwen Holdmann [gwen.holdmann@alaska.edu] Sent: Thursday, August 19, 2010 10:50 PM To: Aubert, Winton G (DOA) Subject: Pilgrim Hot Springs Winton, I would like to confirm that the work conducted through the Alaska Center for Energy and Power (University of Alaska Fairbanks) at Pilgrim Hot Springs is purely intended for research purposes. The purpose of our project, funded primarily through the Department of Energy, is to test the validity of an innovative geothermal exploration technique which involves an advanced airborne infrared survey. To verify this technique we will conduct ground truthing using more traditional geophysical and geologic techniques, as well as collection of new data from six existing wells which will all be used to develop a conceptual model of the site. Eventually, we plan to confirm this model through the drilling of two 500ft gradient holes and two 2500ft confirmation holes to identify the recharge point for the hot springs and measure total heat loss to the surface to correlate to our airborne infrared data. Please let me know if you need any additional information, I am happy to provide it. Gwen Gwen Holdmann, Director Alaska Center for Energy and Power University of Alaska Physical Address: 814 Alumni Drive Mailing Address: PO Box 755910 Fairbanks AK 99775-5910 Cell.(907) 590-4577 www.uafedu/acel2 www.energy-alaska.com www.akenergynetwork.com 8/23/2010 0 Memorandum State of Alaska Oil and Gas Conservation Commission To: Well History Files 1790780, 1790850, 1790900, August 4, 2010 1002740, 1002750, 1002760 Re: Pilgrim Spring Geothermal Drilling and Testing Program - Notes and Coordinates for Wells From: Steve Davies A total of six exploratory geothermal wells have been drilled at Pilgrim Springs, located about 60 miles north of Nome, Alaska. This area is governed by Conservation Order No. 159, issued September 12, 1979, which requires a permit to drill from the Commission for "all wells to be drilled or borings into the soil for any purpose and to any depth in Sections 29, 30, 31, and 32, T4S, R3 OW, KRM, Sections 35 and 36, T4S, R3IW, KRM, and Sections 2,3,and 4, T5S, R3IW, KRM..." Three of these wells, Pilgrim Spring 1, 2, and 3 received permits to drill during 1979 (Permit Nos. 1790780, 1790850, and 1790900). Commission well history files indicate that Pilgrim Spring 1 and 2 were drilled to approximately 150' measured depth and suspended on November 25 and 20, 1979, respectively. There are no records in the Commission's well history file 1790900 to indicate that Pilgrim Spring 3 was drilled. During the summer and fall of 1982, Woodward -Clyde Consultants (Woodward -Clyde), under contract to the Alaska Division of Energy and Power Development, conducted an intensive drilling and testing program at Pilgrim Springs.' The initial well drilled was Pilgrim Spring 3, which had been previously permitted by the Commission. This was followed by the drilling of three additional, unpermitted wells: Pilgrim Spring 4, Mary's Igloo 1, and Pilgrim Spring 5. The results of this program are summarized in Woodward -Clyde's 1983 report, a copy of which has been placed in well history file 1002740. In 2010, Peter Illig of the Alaska Center for Energy and Power at the University of Alaska, Fairbanks conducted a reconnaissance trip to the site to Pilgrim Springs to locate and determine the status of the existing geothermal wells.2 Descriptions and photos of each wellhead indicate that all six wells are shut- in rather than suspended, as indicated by artesian flow and mineralization. The exact location coordinates for these wells are problematic. Coordinates for Pilgrim Spring 1, 2, and 3 listed as footages from section lines on the permits to drill were converted to latitude/longitude using the Commission's RBDMS database. These coordinates are shown on the accompanying satellite photograph by small yellow squares (Figure 1). Latitude/longitude coordinates stored in the RBDMS 1 Woodward -Clyde Consultants, 1983, Phase II: Results of Drilling, Testing and Resource Confirmation, Geothermal Energy Development at Pilgrim Springs, Alaska, Contract 82-0782 with the Alaska Department of Commerce and Economic Development, 62 p. 2 Illig, Peter, 2010, 6-29-2010 Preliminary Reconnaissance Trip Report, Pilgrim Hot Springs Geothermal Exploration, Alaska Center for Energy and Power. Coordinates provided by Illig in UTM, meters, when converted to NAD 83 lattude/longitude using CorpsCon 6.0, plot at the locations indicated by yellow stars on Figure 1. Well locations spotted by Illig on an air photo that accompanies his 2010 reconnaissance trip report are more difficult to translate to the satellite photo. It appears as though Illig's photo is rotated about 20 degree clockwise from north and is also severly stretched along its north -south axis. A prolonged trial and error session was needed to squeeze and rotate this air photo to approximate a close match of the streams and lakes to the satellite photo. But the match is not perfect: lakes and stream meander loops do not match closely between the photos. The well locations from the best -match fit between the air and satellite photos are indicated by the red circles on Figure 1. Accompanying Woodward -Clyde's 1983 report on the results of drilling and testing is a site map that, when uniformly scaled, matches the satellite photo almost exactly. The locations for the Pilgrim Spring and Mary's Igloo wells are indicated on Figure 1 by small, blue circles. When uniformly scaled, the USGS topographic map of this area also nearly perfectly matches the satellite photo and Woodward - Clyde's map. This topographic map is the source for the yellow section lines depicted on Figure 1. Because of the nearly exact match between the map accompanying Woodward -Clyde's 1983 report, the USGS topographic map and the satellite photo, and because Woodward -Clyde field personnel spent weeks in the field (rather than the single day spent by Illig), it is judged that the most accurate locations for the Pilgrim Spring and Mary's Igloo wells are those mapped by Woodward -Clyde. Based on these locations and the section lines derived from the USGS topographic map overly, the best estimates for the well locations are presented in the table, below. Footages measured from section lines converted to latitude/longitude using RBDMS: RBDMS latitude/longitude values converted to NAD 83 using CorpsCon 6: RBDMS (NAD 27) NAD 83 Well Latitude Longitude RBDMS (NAD 27) Well X 65.0917760142764 Y S -T -R -PM Latitude Longitude Pilgrim Spring 1 825' FEL 110' FSL 36 -04S -31W -K 65.0917760142764 -164.925283825097 Pilgrim Spring 2 2565' FEL 55' FNL 03 -05S -31W -K 65.0913250627542 -164.926042200407 Pilgrim Spring 3 2770' FEL 220' FNL 03 -05S -31W -K 65.0908741108309 -164.927370965319 Pilgrim Spring 4 2580' FEL 270' FNL 03 -05S -31W -K 65.0907374577024 -164.926138003074 Pilgrim Spring 5 2595' FEL 790' FNL 03 -05S -31W -K 65.0893162733042 -164.926231665414 Mary's Igloo 1 3295' FEL 220' FNL 03-05S-31 W -K 65.0908741129814 -164.930776865159 RBDMS latitude/longitude values converted to NAD 83 using CorpsCon 6: Plotting the results on the same photo (as close as I could reproduce it), yields the following plot of the accuracy of the coordinate measurements and conversions. The accuracy of measured footages from the section lines appears to be within about 150'. The footages measured from the satellite photo will be used in RBDMS as the best estimate ofpeef and bounds coordinates for these wells. Cc. RBDMS (NAD 27) NAD 83 Well Latitude Longitude Latitude Longitude Pilgrim Spring 1 65.0917760142764 -164.925283825097 65.091028837 -164.927929670 Pilgrim Spring 2 65.0913250627542 -164.926042200407 65.090577861 -164.928687996 Pilgrim Spring 3 65.0908741108309 -164.927370965319 65.090126874 -164.930016710 Pilgrim Spring 4 65.0907374577024 -164.926138003074 65.089990242 -164.928783737 Pilgrim Spring 5 65.0893162733042 -164.926231665414 65.088569025 -164.928877249 Mary's Igloo 1 65.0908741129814 -164.930776865159 65.090126809 -164.933422601 Plotting the results on the same photo (as close as I could reproduce it), yields the following plot of the accuracy of the coordinate measurements and conversions. The accuracy of measured footages from the section lines appears to be within about 150'. The footages measured from the satellite photo will be used in RBDMS as the best estimate ofpeef and bounds coordinates for these wells. Cc. • MEMORANDUM TO FILE From: Waylin Sieler Date August 3, 2010 Subject: Pilgrim Hot Springs wells located at Pilgrim Hot Springs were drilled without permits to drill. These wells were presumably drilled prior to 1979, when Conservation Order #159 established AOGCC jurisdiction over the Pilgrim Hot Springs area (hence, drilling permits were not required). Well files currently exist for PS -1, PS -2, and PS -3, respectively. Only recently did the AOGCC learn of the existence of three additional wells. Utilizing a reconnaissance trip report prepared by Peter Illig of the Alaska Center for Energy and Power (ACEP), the AOGCC determined that the three wells previously known were in -fact wells PS -1, 2, and 3, respectively. Wells identified as PS -4, PS -5, and MI -1 (in the ACEP report) are the previously unknown wells. The information collected about these wells was 411 collected and their respective well files were created. The permit numbers allocated are as follows: .u, � 5, P /CX�, - 2 7/JLQ-243 corresponds with PS -4 5V __O'S A0 2�?S T00,274 corresponds with PS -5 C- cam to TOO -2 fi9 corresponds with MI -1 Please see the enclosed maps, the ACEP report, and the Pilgrim Hot Springs Coordinates List for more information. Pilgrim Hot Springs PS -4 Coordinates 3 August 2010 INPUT OUTPUT UTM, NAD27 Geographic, NAD27 03 - 168W to 162W, Meters North i ng/Y: 7218298 Easti ng/X: 0503475 Convergence: 0 04 01.40951 Scale Factor: 0. 999600148 PS -4 1/1 Latitude: 65.090034188 Longitude: 164. 926063559 Remark: Initial coordinates given in UTM format were converted to latitude/longitude coordinates. Corpscon v6.0.1, U.S. Army Corps of Engineers 0 0 �v}ACEP Cpntpi if- Ftie-t =az d 6-29-10 Preliminary Reconnaissance Trip Report Pilgrim Hot Springs Geothermal Exploration Prepared by: Peter Illig, Alaska Center for Energy and Power, University of Alaska Fairbanks Goals Our preliminary trip to Pilgrim H.S. was intended to locate, map, and determine the status of all 6 wells located at Pilgrim Hot Springs, including those on adjoining MINC land, and to get a general feel for stable ground in the area and potential challenges associated with ground-based surveys planned for later this summer. Notes on Geographic Coordinates When acquiring GPS points for this project, we determined it would be best to use Universal Transverse Mercator (UTM) as normal distances between lat long lines are distorted due to the high latitude arctic location of the site. UTM provides an easy to use square grid system. For this report I used NAD 1927 Alaska (5003), and the units are in meters. Please make sure that when using coordinates in the area to use this coordinate system. Site Overview Pilgrim Hot Springs is road accessible, although the last mile or so is in bad shape. There is a fair amount of stable ground in the surrounding area, and it seems possible to access all 6 existing wells with equipment needed to replace the wellheads without the aid of helicopter during appropriate times of the year. There are numerous historic buildings, including the church, dominating the north section of the area. To the south is the MI -1 (see figure 7), with the Mary's Igloo well being furthest west. Well Descriptions We were able to locate all 6 wells during the trip, and have provided current descriptions of their condition below, with images from the wellheads included in Figures 1-6. Figure 7 shows the relative locations of all the wells. My colleague, Dan Brotherton, is preparing a plan to refit wellheads for all but one or two of these wells so they can be accessed to collect additional data. We have located the original well completion diagrams and other critical information related to the original drilling program in the report 'Results of Drilling, Testing, and Resource Confirmation — Geothermal Energy Development at Pilgrim Hot Springs, Alaska' prepared by Woodward -Clyde Consultants in 1983. This report will be very helpful in developing a plan to rework the individual wells as needed. PS -1 (0503536mW 7218438mN) This well is located furthest north (closest to the church and nearest the main trail). It may very well be the hottest of the wells and appears to have significant artesian flow as evidenced through the leakages. The wellhead has a thick layer of silicious deposits on the exterior which has capped some of the leaks. This well will need to be refitted for further use. PS -2 (0503477mW 7218374mN) Located SW from PS -1 is PS -2. This well seems to be in fairly good shape, and is marked by a large white PVC tube. It is located close to the ground, and does not seem to be leaking. It does not appear 0 0 necessary to replace this wellhead, although access with appropriate instrumentation may necessitate retrofitting a tin valve to the wellhead. PS -3 (0503411mW 7218346mN) West of PS -2 is PS -3. It stands out clearly when surveying the area due to its higher wellhead compared to the others. It is also leaking, and will require refitting in order to access the hole. The silicious seal has sealed past cracks in the metal, however there is a constant artesian flow from at least unsealed leak. PS -4 (0503475mW 7218298mN) This is the well which feeds the main hot tub on the property. It leaks considerably, and has a few tubes connected to the wellhead which are presumably used to feed the tub. As with all the wells described thus far, it will require extensive work to be fully operational. PS- 5 (0503478mW 7218122mN) PS -5 is the located furthest to the south. Additionally, it is in the best shape of all of the wells. The valves seem to be operational, and there is little rust on the wellhead. Hot water comes out of the valve that we tested which is attached to a garden hose. Getting to the well should not present an issue, however it should be noted there is a lake that was covered with a floating mat of grass that both Dan and I fell into. MI -1 (0503262mW 7218327mN) MI -1 is located furthest west on the field. It was drilled for a hot water source on behalf of Mary's Igloo Native Corporation (MINC). It has extensive damage to the upper part of the well, where a large crack can be seen in the wellhead. The flow is constant from the crack, with much of it being sealed with silica. This wellhead should also be replaced if it is to be accessed in the future for research or development purposes. Conclusions Dan Brotherton will be writing a report suggesting further steps to be taken on the existing wells to make them operational. This report will be shared with the well owners, Unaatuq, LLC and MINC. The next step will be to map culturally sensitive areas (grave sites, historical buildings, etc.) and property boundaries. This task is scheduled for late July or early August. Prior to this trip we will set up a phone conference with all the parties involved to address questions and concerns regarding that trip, to go over schedules, and to develop a backup plan. Figure 7, which is located on the next page, includes all of the well locations and some of the buildings on the property. Once more information on historic sites, and other important cultural features are identified, they will be added to this map. Any future drilling objectives will take all of this information into account so that any effects are minimized. For additional information or questions about this report please contact: Peter Illig, ACEP illig.ak@gmail.com 907-602-1332 (cell) iz 9qp #�1 A" t !r !Y PW .. I s 4 � N #�1 A" t !r !Y PW .. I s 4 � N 0 Figure I Ps a 0 . . <J, Figure %P&a Figure S. PS -5 Figure 6. MI -1 Meters Legend 0 165 330 660 990 1,320 N Man Made Structures . 9 , 3 8 6 %, A, Well Locations �/ 1 centimeter = 94 meters Figure 7. Map of Pilgrim Hot Spring Well Locations OneTingle Avenue Creek Center 100 Pringle Woodward-Clyde Consultants Walnut Creek, CA 94596 415-945-3000 April 15, 1983 Division of Energy and Power Development 7th Floor Frontier Building 3601 "C" Street Anchorage, Alaska 99503 i> Attention: Mr. Dale Rusnell Gentlemen: Woodward-Clyde Consultants, as completion of our Contract No. 82-0782 with the Alaska Department of Commerce and Economic Development, is pleased to submit this final Phase II report "Results of Drilling, Testing and Resource Ccnfirmaticn--Geothermal Energy Development at Pilgrim Springs, Alaska", in two volumes. This volume contains a detailed description of Woodward-Clyde's 1982 drilling and testing program, including location and soil-helium surveys, the completion of four new geothermal production wells, the interpretive results of extensive hydrothermal testing, and as complete an assessment of the geothermal resource potential as present data permit. A number of questions regarding the nature and location of the circulating ground water and geothermal heat source remain unanswered. A second volume, under the same title as this, contains all the basic data t collected during the 3-month 1982 field investigation, and serves as an k' appendix to this interpretive. Very truly yours, Ben E. Lofgren Project Manager BEL:rm Consulting Engineers, Geologists and Environmental Scientists Offices in Other Principal Cities GEOTHERMAL ENGERGY DEVELOPMENT at PILGRIM SPRINGS, ALASKA PHASE II: Results of Drilling Testing and Resource Confirmation April 15, 1983 Submitted to State of Alaska Division of Energy and Power Development 3601 "C" Street Anchorage, Alaska 99503 by Woodward -Clyde Consultants One Walnut Creek Center 100 Pringle Avenue Walnut Creek, CA 94596 15267A • TABLE OF CONTENTS 4.0 GEOLOGY 21 4.1 GEOLOGIC SETTING 21 4.2 PREVIOUS GEOLOGIC AND GEOPHYSICAL INVESTIGATIONS 23 4.3 GEOLOGIC CONDITIONS IN THE WELL FIELD 24 5.0 WELL TESTING 29 5.1 INTRODUCTION 29 5.2 INTERFERENCE EFFECTS AMONG WELLS 29 5.3 GEOCHEMISTRY OF WELL WATERS 30 i Page LIST OF TABLES LIST OF FIGURES iv 1.0 EXECUTIVE SUMMARY 1 2.0 INTRODUCTION 4 2.1 LOGISTICS AND SCHEDULE 6 2.2 PERMITS g 2.3 RESULTS OF PREVIOUS INVESTIGATIONS 9 2.4 FIELD SURVEYS 10 2.5 SOIL -HELIUM INVESTIGATION 12 2.6 INVENTORY OF SUPPLIES LEFT AT PILGRIM SPRINGS 13 2.7 ACKNOWLEDGMENTS 13 3.0 DRILLING 15 3.1 INTRODUCTION 15 3.2 WELL PS -3 16 3.3 WELL PS -4 17 3.4 WELL PS -5 1s 3.5 WELL MI -1 19 4.0 GEOLOGY 21 4.1 GEOLOGIC SETTING 21 4.2 PREVIOUS GEOLOGIC AND GEOPHYSICAL INVESTIGATIONS 23 4.3 GEOLOGIC CONDITIONS IN THE WELL FIELD 24 5.0 WELL TESTING 29 5.1 INTRODUCTION 29 5.2 INTERFERENCE EFFECTS AMONG WELLS 29 5.3 GEOCHEMISTRY OF WELL WATERS 30 i 0 TABLE OF CONTENTS (continued) 5.4 TEMPERATURE GRADIENTS AND PROFILES 5.5 EVALUATION OF RESERVOIR PARAMETERS 6.0 SURFACE HYDROLOGY 7.0 RESOURCE ASSESSMENT 7.1 GEOTHERMAL SYSTEM BOUNDARIES 7.2 BOUNDARY FLUXES 7.3 INTERNAL SYSTEM FUNCTIONS 7.4 SYSTEM HEAT AND WATER BALANCE 7.5 RESOURCE BASE WITHIN THE MODELED PART OF THE GEOTHERMAL SYSTEM 7.6 ACCESSIBLE GEOTHERMAL RESOURCE BASE 7.7 LIMITATIONS OF THE CONCEPTUAL MODEL 8.0 RECOMMENDATIONS FOR FUTURE WORK 9.0 REFERENCES TABLES FIGURES ii Page 32 36 41 43 44 44 48 49 51 51 52 53 59 • LIST OF TABLES Table No. Title 1 Summary of Geothermal Well Completion Information 2 Summary of Geophysical Data Obtained from Test Wells Completed at Pilgrim Springs, Alaska 3 Water Quality of Wells and Springs 4 Summary of Estimates of Transmissivity and Hydraulic Conductivity for Wells at Pilgrim Springs, Alaska iii WOOd1111dl'!�-Clyde Consultants LIST OF FIGURES Figure No. Title I Location of Pilgrim Springs Geothermal Wells and Access Trail from Taylor Highway R : 2 Schedule of 1982 Field Activities 3 Location of Geothermal Wells and 1979 Temperature Contours to 100- `;:. Meter Grid 4 Surveyed Location of Six Geothermal Wells with Respect to Well PS -2 5 Correlation of Soil -Helium Concentrations with 1979 Shallow -Temperature Contours , 6 i Casing Profile of Well PS -3 7 Casing Profile of Well PS -4 8 Casing Profile of Well PS -5 9 Casing Profile of Well MI -1 10 Relationship of Pilgrim Springs Well Field to Surface Streams 11 Generalized Geologic Log of Well PS -4 12 Initial Shallow Temperature Gradients at Four Well Sites 13 Temperature Profiles of Well PS -1, September 25, 1982 iv Woodward -Clyde Consultants 14 Temperature Profiles of Well PS -2, September 26. 1982 19 Temperature Versus Depth Profiles of Six Geothermal Wells 20 Relationship Between Increased Artesian Head and Increasing Depth, September 22, 1982 21 Semi -logarithmic Plot of Head vs. Time for PS -2 During Flow Test of PS -2 22 Semi -logarithmic Plot of Head vs. Time for PS -4 During Flow Test of PS -4 23Semi-logarithmic Plot of Head vs. Time for MI -1 During Flow Test of MI -I 24 Semi -logarithmic Plot of Head vs. Time for PS -3 During Flow Test of PS -3 25 Semi -logarithmic Plot of Discharge vs. Time for PS -5 During Flow Test of PS -5 26 Conceptual Model of the Hottest Area of Pilgrim Springs Geothermal System 15 Temperature Profiles of Well PS -3, September 25, 1982 16 Temperature Profiles of Well PS -4, September 27, 1982 17 Temperature Profiles of Well PS -5, September 26, 1982 18 Temperature Profiles of Well MI -1, September 25, 1982 19 Temperature Versus Depth Profiles of Six Geothermal Wells 20 Relationship Between Increased Artesian Head and Increasing Depth, September 22, 1982 21 Semi -logarithmic Plot of Head vs. Time for PS -2 During Flow Test of PS -2 22 Semi -logarithmic Plot of Head vs. Time for PS -4 During Flow Test of PS -4 23Semi-logarithmic Plot of Head vs. Time for MI -1 During Flow Test of MI -I 24 Semi -logarithmic Plot of Head vs. Time for PS -3 During Flow Test of PS -3 25 Semi -logarithmic Plot of Discharge vs. Time for PS -5 During Flow Test of PS -5 26 Conceptual Model of the Hottest Area of Pilgrim Springs Geothermal System VI/OotIaColrGyde Conadtants 1.0 EXECUTIVE SUMMARY The Pilgrim Springs geothermal area is located about 40 miles north of Nome, Alaska, in the lowlands of Pilgrim River Valley. It represents a 0.7 -square -mile thawed area, surrounded by'permafrost to depths of greater than 300 feet. Six geothermal wells, ranging in perforated depth from 60 to 1,001 feet, are now completed at Pilgrim Springs._ These are clustered in the hottest part of the geothermal anomaly one-quarter mile southwest of the historic Pilgrim Springs church. Two of the wells, PS -I and PS -2 (Figure 3), were drilled in 1979 and were then perforated and tested in the summer of 1982. The four deeper wells (PS -3, PS - 4, PS -5, and MI), were drilled and tested in the summer of 1982. The reporting and interpretation of the drilling and testing of these six wells and an assessment of the geothermal resource potential of the area, based on the findings of the 1982 drilling and testing program, are the principal objectives of this report. K The 1982 drilling and testing program by Woodward -Clyde Consultants (WCC) was preceded by several seasons of extensive geologic and geophysical field work by the Geophysical Institute of the University of Alaska and by the drilling of two shallow test wells by the State. Published reports from these investigations served as a substantial background for the 1982 program. For the 1982 field investigation, the survey control network, the location and depth of wells drilled, and the geologic framework of the region were derived from these earlier studies. The significant contribution of the Geophysical Institute and the State studies and the continued interest and support of the respective researchers in the success of the 1982 investigation are gratefully acknowledged. All six wells of the Pilgrim Springs project were drilled within the 600C contour of Turner and Forbes (1980), wherein soil temperatures at the 15 -foot (4- to 5-m) depth exceeded this amount (Figure 3). All wells were located to assist in defining the magnitude and extent of the geothermal resource, to attempt to identify the location and nature of hot-water source, and also, to serve as geothermal supply wells. Well PS -3 was drilled a few feet southeast of the highest measured subsurface soil temperature of the 1979 survey (960C at 276 m west and 276 m south; Osterkamp 1 � wooaayde cw,sueants and others, 1980) and a few feet northwest of the highest measured soil -helium concentration 013.76 ppm, Figure 5) of the 1979 investigation. Also, well PS -5 was sited to test the possibility that the inferred intersecting lineaments (Figure 3) observed on satelite photographs might be the source of rising hot waters, as suggested by Turner (written communications, 1982). Although the drilling and testing of these wells have confirmed a significant geothermal resource for the area, studies to date have not identified either the location or the characteristics of the geothermal source. All six wells penetrate the extensive shallow geothermal aquifer system that apparently underlies much of the Pilgrim Springs thawed area (Turner and Forbes, 1980). This saline 900C aquifer system has artesian heads a few feet above land surface, and feeds the numerous thermal seeps and springs located principally southwest of the church. Drilling logs and temperature profiles of the six wells confirm the following three - unit hydrothermal flow system within the well field: 1) an upper sequence of confining deposits with very high thermal gradients (up to 3500C per 100 feet); 2) the productive artesian aquifer system described above, which is about 60 -feet thick and must have considerable horizontal ground -water circulation to maintain the heat transfer evidenced throughout the area; and 3) a continuing downward sequence of valley -fill deposits with cool, fresh -water circulation. The temperature profiles of the two deepest drill, holes (Figure 19) indicate the deep thermal gradient of sediments below the surficial zone of ground -water circulation to be about 2.20C per 100 feet, about twice the normal gradient of a non -geothermal area. The nature of this three -unit hydrothermal flow system had been precisely predicted by Wescott and others (Turner and Forbes, 1980) from deep electrical resistivity measurements. In the completion of the four 1982 wells, blank casing was used through the shallow thermal aquifer system (Figures 6 to 9) so that deeper zones could be hydraulically tested. The option remains with each of these wells whether to use these wells to produce deep fresh water or to plug and perforate these wells to produce high - 2 OrOCtYIfAP�C*rWAdtew tS plKe temperature geothermal waters. The plugging and perforating of these welts can be accomplished on a low budget without a drill rig. A conceptual model of the Pilgrim Springs geothermal system has been developed. This is based on the best hydrothermal data available for the area. Using this model to analyze the energy and the water inflow to and outflow from the system, the geothermal resource base of the hottest part of thawed area, (that area southwest of the church within the 300C thermal contour shown on Figure 5), was calculated. As summarized in Figure 26, a continuing supply of probably 19 to 24 MW of geothermal energy apparently is fed into the modeled system from some unidentified source. t This is balanced by an energy outflow from the system of 6 MW to the atmosphere, 2 MW by thermal springs, and 11 to 16 MW by ground -water movement from the area. In addition, a 20 -year supply of energy at a use rate of 1.5 MW is in storage in the shallow thermal aquifer system. It is noteworthy that the energy stored in the shallow geothermal aquifer system, significant as it is, represents less than 10 percent of the total thermal resources. More than 90 percent of the resource is available as a continuing supply from some unidentified source. If the source can be located, not only will temperatures be �i hotter but a more effective well field can be designed. Additional research is suggested to better define the geothermal source before additional drilling is considered. Not all of the roughly 25 MW of geothermal energy estimated for the Pilgrim Springs well -field area is effectively recoverable. The useable part of the resource will be probably 50 to 75 percent of this amount. Also, the impact of fluid extractions from the thermal aquifer system must be considered. Large extractions from the natural geothermal flow system will undoubtedly cause significant changes in either soil temperatures in the hottest part of the thaw area or smaller and cooler ground -water discharges from the area. Optimal use of the total resource will depend on carefully planned developments. 3 wooaClyde Oxtsultants 2.0 INTRODUCTION On February 16, 1982, authorization was given by the Alaska Division of Energy and Power Development (DEPD) for Woodward -Clyde Consultants (WCC) to proceed with an extensive two-phase field investigation of the geothermal resources of Pilgrim Springs, Alaska. This investigation was designed primarily to drill and test four geothermal wells and to assess the resource potential of this historic hot spring oasis in remote interior Seward Peninsula. Previous investigations by various state agencies had provided extensive geological, geophysical, and hydrothermal back- ground information for this 1982 drilling and testing program. Phase I of the WCC investigation included: 1) a review of reports and background i 4 data of studies by the Geophysical Institute of the University of Alaska, the Alaska Division of Geological and Geophysical Surveys and by the Division of Energy and Power Development; 2) the preparation of a detailed design and a work plan for the drilling and testing of geothermal wells in the hottest area of Pilgrim Springs geothermal anomaly; and 3) the obtaining of necessary permits and agreements to implement this field investigation. These Phase 1 activities were completed on May 11, 1982 with the submittal of WCC's report, "Plans for Drilling, Testing and Resources Confirmation - Geothermal Energy Development at Pilgrim Springs, Alaska." The Phase I report summarized the design information pertinent to the Pilgrim Springs project, most of which will not be repeated in this Phase 11 final report. Phase 11 of the investigation included the following activities: 1) The procurement and mobilizing of all supplies, equipment, and logistical support necessary for the field investigation; 2) The perforating and testing of two shallow geothermal test wells drilled by the state in October -November 1979; 4 SASOOdWAfi�Clyde Cionadtants 3) The drilling, logging and testing of four deeper geothermal production wells; 4) The collection and analysis of shallow soil samples for helium - concentration investigations; and 5) The preparation of an interpretive report assessing the geothermal resource potential of the area. Although the drilling and testing of only three wells were originally specified in the contract, a fourth well was added by contractual agreement when down -hole caving of the intended deep well (PS -4) prevented further deepening of this well. All field i work at Pilgrim Springs, which includes activities 1 to 4 above, were completed K during June, July and mid-September 1982. This Phase II final report presents the pertinent original and interpreted field data of :` the drilling and testing program; a detailed description of the four geothermal well completions, performances and tests; and as complete an assessment of the geo- thermal resource potential of the area as available data permit. As discussed in Section 7.0, Resource Assessment, questions remain as to the location and nature of the deep goethermal heat source, the rate and direction of hot ground -water flow in the shallow geothermal aquifer, the nature and extent of reservoir boundary conditions, and possible heating effects beneath Pilgrim River. It is hoped that additional flow testing of the shallow thermal aquifer system, as recommended later in this report, will supplement the findings of this WCC investigation in answering some of the unresolved resource questions of the area. Finally, it should be noted that three different systems of reporting lengths and distances are used in this report. Although the system of feet and tenths is preferred throughout the report, both the metric system and inches and fractions are used in specific areas. Of necessity, we have continued to reference field and map locations to the 100 -meter grid system established earlier by the Geophysical Institute when referring to the locations of wells, thermal contours, and helium -sampling sites. 5 0 VMOO�IWAl ClydeConsuftants Also, when designating pipe and fitting sizes, we have used the conventional nomenclature of inches and fractions. In several areas of the report, dual designations are used to simplify reporting of the data. 2.1 LOGISTICS AND SCHEDULE Because of the remoteness of Pilgrim Springs, a major aspect of the total project effort involved the mobilization of equipment, supplies, and manpower; the operational maintenance of equipment; and the maintenance of communications and logistic support throughout the project. Because of late May and early June storms throughout Alaska, field activities of the Pilgrim Springs project were delayed more than two weeks from original plans. The barge shipment of pipe, lumber and drilling supplies from Seattle, scheduled for arrival in Nome in late May and promised for delivery at the lighterage yard two days later, actually was not available for pickup until mid-June and then only on a delayed piece -meal basis. The first loads of equipment and supplies started up the Taylor Highway by commercial trucking on June 16, and the first supplies arrived in Pilgrim Springs on June 18. Approximately 100 tons of equipment and supplies were required to complete the Pilgrim Springs project. Most of the well casing, drill pipe, drilling supplies, and timbers used to elevate the drill rig were assembled in Seattle and shipped to Nome by barge. The Nodwell-mounted Failing .1500 drill rig, a flat-bed Nodwell for freight hauling and project support, and most of the testing equipment and camp supplies used on the project were assembled in Anchorage and shipped to Nome by air freight. From Nome, this 100 tons of freight and equipment were transported north- ward 55 miles over the paved Taylor Highway by commerical trucking, and were unloaded at a trailhead staging area. From trailhead, the freight was moved one load at a time by fiat -bed Nodwell over the 8 miles of unimproved Pilgrim Trail (Figure 1) to the project site. About 20 -flat-bed loads from trailhead were required to bring all the drilling supplies and a continuing supply of fuel from Nome into the project site. Each round trip to trailhead for supplies required 6 to 8 hours of a two-man crew. r1 r 0 Drilling supplies and equipment were stockpiled during the drilling and testing program in the vicinity of well PS -3. Shipment of supplies into Pilgrim Springs was scheduled as needed and continued through most of July. Beginning in mid-July, return shipment of equipment to trailhead and then to Nome and Anchorage began as soon as items of equipment were no longer needed on the project. The drilling and casing of the last well of the project were completed on July 28, and full demobilization was completed on August 1, 1982. Unused pipe and reusable lumber left at the project site are stockpiled in the trees north and south of PS -1 (see Appendix A). As shown in Figure 2, preliminary field surveys, soil sampling for helium analyses, and the testing of the 1979 -drilled shallow wells (PS -1 and PS -2) began on June 22, ' and actual drilling of PS -3, the first of four deeper production wells, began in the evening of June 25. In order to obtain equilibrated temperature profiles and reservoir hydraulic heads at each of the six geothermal wells, an unplanned return visit to Pilgrim Springs was made in late September, seven weeks after all wells had been closed and locked. Because of severe storm conditions, this intended three-day assignment at Pilgrim Springs extended to a full week. The results of these late a September data, however, have proved invaluable in our understanding of the geothermal resource of this area. ' All phases of the Pilgrim Springs project benefited greatly from the careful advance planning and scheduling required by DEPD and reported in the WCC Phase I report. With few exceptions, WCC was able to follow in the field the procedures of this advance planning, even though the entire schedule was delayed about two weeks. Some of the more serious unanticipated problems that delayed the progress of the drilling and testing program were: 1) An extended delay of 2 to 6 days for delivery of needed supplies from the barge lighterage yard in Nome. This involved a week of negotiating with the lighterage company and a delay of shipments up Taylor Highway. The promised 2 -day delivery schedule extended to 8 days for some major items. 7 0 0 V:OO�IWAt'�Clyde Consultants 2) Radio communications to and from Pilgrim Springs were never satisfactory and, on several occasions, resulted in delayed activities on the project and unplanned charter flights from the Nome airport. Even with first-class radio equipment in operation on the project at all times, local atmospheric storms made communications with Fairbanks and Anchorage impossible for several long periods. The setting of Pilgrim Springs in the communication shadow behind the Kigluaik Mountains makes radio conversations with Nome impossible. 3) Caving conditions in well PS -4, the intended deep well of the project, caused extended delays. A major cave-in at a depth of 881 feet resulted in the loss of a drill bit, stabilizer, and geophysical logging probe in the drill hole. This loss required the drilling of a fourth well and the air shipment of surface casing, drilling mud, and additional equipment to the project site. 2.2 PERMITS As discussed in detail in the WCC Phase 1 report, six types of permits and applications were obtained before proceeding with the Pilgrim Springs project. These are: 1) Access to the Pilgrim Springs project area across public lands from the Taylor Highway, 2) Permits to drill and test geothermal wells on public and private lands, 3) Discharge permits, to dispose of geothermal fluids, 4) Water -rights application, and 5) Impact to wetlands. 8 woos ra.clyae Coutdtants Eleven federal, state and local agencies were contacted to determine permit requirements and to obtain needed permits, applications, and letters of non- objection. All permits were received before field activities began. For a list of agencies and individuals contacted, refer to the WCC Phase I report. x- 23 RESULTS OF PREVIOUS INVESTIGATIONS Detailed investigations of the Pilgrim Springs geothermal area by the Alaska Geophysical Institute was begun in 1974 and has been continued by this and other state agencies through 1980. Many of the results of these investigations (reports referenced in Section 9.0) provided a substantial background for WCC's 1982 drilling and testing program. A review of these early findings is included in Sections 4.1 and 4.2 of this report. Every effort was made during the 1982 drilling and testing program to coordinate WCC activities with the earlier Geophysical Institute findings and reports. Because all earlier geophysical, shallow thermal gradient, and helium data and the 1979 well locations were referenced to an arbitrary 100 -meter field grid system established by the Geophysical Institute, the corresponding 1982 WCC field data were tied to a reconstruction of this same grid system (see Section 2.4 -Field Surveys). The expanded 1982 helium -sampling program (see Section 2.5) was designed to comple- ment the earlier studies of the Geophysical Institute, and Drs. Eugene Wescott and Donald L. Turner selected the sites for the 1982 WCC sampling. Also, the location of WCC's fourth well was sited to test the possibility that the inferred intersecting lineaments observed on satelite photographs might be the source of rising hot geothermal waters, as suggested by Dr. Turner. In 1979, Wescott and others (Turner and Forbes, 1980), using principally deep electrical resistivity measurements, conceptualized with detail and precision the vertical profile of the geothermal reservoir system in the vicinity of the present well field. The abrupt temperature inversion of the three -unit hydrothermal flow system (see Figure 19), verified by 1982 drilling, was clearly described in these earlier studies. This gives greater credence to the information on the thickness and lateral 9 Clyde Colnstdtalnts extent of the shallow reservoir system, which is based largely on geophysical studies and as yet is unverified. A number of questions raised by Gosink and others (1980) have been addressed in this Phase II report (see Section 7.0 - Resource Assessment). Unfortunately, the 1982 drilling and testing program did not obtain answers to all of these questions. A scheme designed to obtain many of these answers is discussed in Section 8.0, Recommendations for Future Work. 2.4 FIELD SURVEYS As noted earlier, previous studies by the state used the 100-meter grid system established by the Geophysical Institute to identify all geophysical, shallow- temperature, and helium sampling and well locations in the field and on maps. This grid system was oriented in a north-south and east-west direction, with an origin arbitrarily located at a basketball standard north of the old Pilgrim Springs church. > j Unfortunately, most evidence of the 1979 100-meter grid system was lost by March 1982 when WCC engineers first visited the area. All lath markers left in 1979 had } been systematically removed, the basketball standard had been moved, and only a few weathered pieces of flagging along grid lines were found tied to the trees. In order for the 1982 well locations and sampling sites to correlate with 1979 published data, it was necessary to re-establish the 1979 100-meter grid system early In the Pilgrim Springs field investigation. However, since the 1979 grid system was laid out using a Brunton compass for direction and a metered nylon thread for distance, it was accepted that: 1) an exact replication of the earlier survey would not be possible; and 2) the inaccuracies of the re-established grid would increase the farther the grid lines extended from the point of origin. Problems of re-establishing the 1979 grid were the greatest in the heavily vegetated areas that cover about half of the grid area. The two wells drilled in 1979, wells PS -1 and PS -2, were the only landmarks found in 1982 in the area of principal interest that tied to the 1979 grid system. Thus, the 10 0 0 Woodward -Clyde Consultants coordinate locations of wells PS -1 and PS -2 reported by Klein (in Turner and Forbes, 1980, page 22) were used as the reference control for the 1982 re-established grid system. In the 1982 field surveys, PS -1 was assumed to be located 200 meters south and 150 meters west of the earlier point of origin. From PS -1, a north -south (calculated from a magnetic bearing taken at a point 100 -feet from well PS -1) and an east -west 100 -meter grid system was laid out in the field. An engineer's transit and a specially calibrated 200 -meter -long, braided -cable "chain" were used to layout the restored 100 -meter grid. Grid designations continued to reference distances south and either east or west from the original grid origin near the church. On the restored grid, the location of well PS -2 was measured to be 258.03 meters south and 208.30 meters west of the grid origin (instead of the 258 meters south and 207 meters west reported by Klein). At no other location in the grid area was there an opportunity to measure in the field the accuracy of the 1982 survey in replicating the coordinate locations of the earlier 1979 survey. Figure 3 shows the location of the six geothermal wells (and the temperature contours of the 1979 shallow soil temperature survey) with respect to the restored grid system. Figure 4 shows the surveyed location of the six geothermal wells with respect to the location of well PS -2. Of particular interest was the shift of the west boundary of the private lands about 30 feet east from the location reported in the earlier surveys (compare Figures 3 and 4 herein with Figure 3 of the Phase I report). This west boundary line was established by projecting a north -south line through a 1978 Bureau of Land Management boundary corner located about 432 feet north and 39 feet east of well MI -1. Table 1 gives the calculated metric coordinates of the six geothermal wells. In order to provide a basis for calculating hydraulic flow gradients throughout the geothermal well fields, a second -order level survey was completed in 1982. Since no established reference bench marks were known to exist in the Pilgrim Springs area, an arbitrary reference datum was established at well PS -3. The top of the upper flange on the 10 -inch gate valve (not the blank cover plate bolted above the upper flange) was assigned the arbitrary elevation of 25.00 feet above mean sea level. This appeared to be a reasonable elevation based on contours of the published U.S. 11 WoodwardrOyde Conadtslnts Geological Survey topographic map of the area. Corresponding measuring points on the other five geothermal wells in the area were established as the top of the upper flange on the main control valve on each well. Surveyed elevations, based on the assumed PS -3 datum, were established at each well and at several of the local surface -water drainages. Table 1 gives the bench mark elevation of each of the six wells. 2.5 SOIL -HELIUM INVESTIGATION Concentrations of helium in surface soils have been correlated with geothermal anomalies in many areas of Alaska and the world. Such a correlation was confirmed at Pilgrim Springs in 1980 by Wescott and Turner (1981, pages 43-47). During their study, the helium concentration of 24 soil samples, from a depth of 2.5 feet (75 cm) along two lines across the Pilgrim Springs thaw zone, were correlated with ground temperatures measured at a depth of 15 feet (4.5 m) at these same locations. For the WCC study, additional helium sampling was thought to be useful in further defining the Pilgrim Springs geothermal anomaly and in siting the wells to be drilled in 1982. Using a soil sampling array suggested by Wescott and Turner (Figure 3 of WCC Phase I report), 72 additional soil samples were collected from a depth of 2.5 feet with a 3 - inch hand auger. Each sample was immediately sealed in an air -tight pint-sized can, using equipment and procedures supplied by HEXCO International, Inc., of 19423 N. Turkey Creek, Suite F, Morrison, Colorado 80465, telephone (303) 697-6062. The canned samples were air -shipped to Colorado, where HEXCO completed the helium concentration assessments and telephoned the results to Alaska in time to assist in siting the last three wells of the project. Figure 5 shows the measured soil -helium concentrations at the 18 (1979) and 72 (1982) sampling sites. As can be seen in this figure, a reasonable correlation exists between the helium concentrations and the shallow temperature contours of the 1979 survey. At only two locations did the two sets of data show different trends. At coordinate 200S/250W, a relatively high helium concentration is not reflected in the 12 %as_ 4_2 C1yde Col stdteants over-simplified configuration of the earlier temperature contours. Also, at coordinates 3255 and 350S/200W, the high helium values suggest that, with closer- spaced temperature data, the 700C contour of this earlier survey probably would have extended southward around these two locations. Based on the results of both the soil-helium concentrations and the shallow temperature-gradient surveys at Pilgrim Springs, it is concluded that these two surficial techniques do, in general, supplement and re-inforce each other in identifying deeper geothermal sources. In applying either technique, however, the significant influence of different soil types and varying soil-moisture conditions must be considered. 2.6 INVENTORY OF SUPPLIES LEFT AT PILGRIM SPRINGS Appendix A includes a detailed list of used and unused lumber, pipe and other supplies left at Pilgrim Springs after the 1992 field season. These supplies were stockpiled in the trees immediately north and south of well PS -1. When the project closed, these supplies were in good condition and available for future use if needed. The cost of exporting these supplies to Nome by Nodwell was prohibitive. If a road is completed into Pilgrim Springs in the near future, these supplies will have a resale value in other areas and, therefore, are subject to theft if left unattended. 2.7 ACKNOWLEDGMENTS Many organizations and individuals were involved in the successful completion of this Pilgrim Springs project. To each, our gratitude and appreciation are extended. Special credit is given to Donald R. Markle of DEPT) for his interest and close attention to the success of all aspects of the project. WCC's two subcontractors, Energy Services, Inc. (ESI) of Idaho Falls, Idaho (with engineers Jay Kunze and Ray Gould on site) and Exploration Supply and Equipment, Inc. (EXSCO) of Anchorage, Alaska (with president Vic Mittasch and drillers Mark Knight and Ernest Dennis) were 13 a 0 Wbodwwd-C1ydeConsuRwft actively involved in the planning, mobilization, and drilling and testing of the project, and deserve much of the credit for the successful completion of this challenging investigation. Drs. Eugene Wescott and' Donald Turner of the Alaska Geophysical Institute contributed essential background information and guidance. Also, Professor Michael Economides and graduate student Paul Chamberlin rendered invaluable field assistance. Mary Moorman and .her assistant and Dr. Clay Nichols of the Alaska Division of Geologic and Geophysical Surveys conducted extensive geochemical tests on well waters and gases in the field and laboratory. Also, Dr. Robert Forbes contributed numerous suggestions and ideas during the planning and completion of the field investigations. Later, he reviewed the entire final report and contributed some of the discussion on the geologic setting and recommendations for future work at Pilgrim Springs. Special thanks and appreciation is expressed to: C. J. Phillips, Nome, for the use of the buildings at Pilgrim Springs for living accommodations; Louis Green and family for use of equipment and services at Pilgrim Springs; Robert Bean for use of office facilities in Nome and special services throughout the project; Richard Foster of Poster Aviation and his pilots for continually scheduling flights and running errands under sometimes adverse conditions; Mr. Jim Thrasher for the use of his equipment yard in Nome and for giving assistance in several emergencies; and the many businesses in Nome that provided support to the project. To all of these we acknowledge their full support and cooperation. Representing Woodward -Clyde (WCC) on the project: Ben E. Lofgren served as project manager and principal author of the Phase I and Phase II reports, David L. Kirchner and Sheila Roebuck were hydrogeoiogists in the field and during the report preparation, Robert Dugan handled the logistics responsibilities and some geology assignments, and Charles Andrews contributed the section on resource assessment. 14 3.0 DRILLING 3.1 INTRODUCTION Figure 3 shows the location of the two geothermal wells (designated PS -1 and PS -2) drilled in 1979 at Pilgrim Springs (Klein, 1980) in relation to the shallow thermal contours of Osterkamp and others (1980). For precautionary reasons, these wells were not drilled in the area of apparent highest shallow subsurface temperatures. Because of severe weather conditions during late 1979, these wells were not perforated or adequately tested when drilled. One of the assignments of the 1982 drilling and testing program was to perforate, conduct flow tests, and provide temperature logs of these wells and to assess their hydrothermal potential with the other geothermal wells scheduled to be drilled during 1982. Also shown on Figure 3 are the locations of the four geothermal wells drilled during the 1982 season. These wells, designated PS -3, PS -4, PS -5, and MI -1 (Mary's Igloo -1), were designed to be larger and deeper than the 1979 wells and were located to test the hotter and deeper part of the geothermal reservoir. MI -1 was sited on public lands designated as native -selection lands. For a more detailed description of the objectives and design features of these wells, see WCC Phase I report of this project. Figures 6 through 9 herein show completed depths and casing profiles of these four wells. Table I summarizes the completion information of all six wells. The results of the 1979 geothermal studies and drilling indicated that high fluid pressures and high reservoir temperatures could be encountered during the drilling of the 1982 geothermal wells. Because both high pressures and high temperatures make drilling more difficult, it was essential that a blow-out preventer be attached to a cemented well casing in the drill hole at all times. To provide for this protection, it was necessary to: 1) elevate the drill rig 4 feet above the land surface (see Figure 5, WCC Phase I report), and 2) to start each well with a surface string of 16 -inch casing followed by an inner 10 -inch casing, each tightly cemented throughout their depth to the formation (Figures 6 through 9). The telescoping sequence of casing sizes required by these wells used considerable additional time and materials but was 15 WOOd1• W Colmukat'1ts necessary for the safety of the project. Figure 2 shows the dates when drilling of the four 1982 geothermal wells occurred. 3.2 WELL PS -3 Well PS -3 was the initial introduction to the unusual drilling conditions of Pilgrim Springs. Not only were there continued problems of keeping the equipment operating and drilling supplies on hand in this remote area, but also, numerous delays resulted from tightly cemented zones and heaving conditions that sometimes closed the drilled hole before casing could be installed. PS -3 was spudded in at 1630 hours on June 25, 1982, using a 20 -inch auger bit. Hot water was immediately encountered at a depth of only 4 feet, and the loose sandy formation continued to slough into the augered hole. No cuttings were being brought to the surface. Bentonitic mud was added in an attempt to keep the hole open, but without success. Augering was continued to a depth of 17 feet, where a cemented sandstone layer was encountered that was too hard for the auger bit to penetrate. At this depth, mud temperatures were alarmingly hot -- approximately 770C at 17 feet. There was concern that blow- out conditions might be encountered in the well below what appeared to be a 17 -foot "caprock" and before casing could be cemented in the hole and the blow-out prevention equipment installed. At this point, 16 -inch casing was forced into the mud -filled hole to a depth of 17 feet, and this surface casing was tightly cemented to the formation. Inside the 16 -inch casing, a 14 -3/4 -inch drill bit rapidly drilled through the cemented sandstone. Drilling mud was added to keep the formation from caving, and the continuous circulation of cool drilling mud kept the temperatures in the mud -filled hole considerably cooler than formation levels. Ten -inch casing was lowered in the 14 -3/4 -inch drill hole to a depth of 58 feet (Figure 6), and this was also tightly cemented to the formation. After the cement of the 10 -inch casing had time to cure, the blow-out prevention equipment was bolted to the 10 -inch casing, and drilling continued through the blow-out preventer and 10 -inch casing using a 9 -7/8 -inch bit. 16 WOOC�YViiPL�Clyde Cona dtants Figure 6 shows the casing profile of well PS -3 as completed, and Table i gives a summary of well completion information. Well PS -3 was completed on July 4, nine days after it was begun. Blank 6 -inch casing extends to a depth of 167.5 feet, below which perforated 3 -inch casing extends to the well bottom at a depth of 260 feet. The well is presently equipped with a 10 -inch gate valve bolted to the 10 -inch casing and with two 2 -inch discharge ports with 2 -inch valves. The main gate valve is padlocked for security and a concrete pad surrounds the 10 -inch casing. 3.3 WELL PS -4 Well PS -4 was scheduled to be the deepest well of the project; it was to be drilled to bedrock at an estimated depth of 1450 to 1500 feet. Drilling commenced on July 5, 1982, and proceeded much as described for PS -3 above. Surface strings of 16- and 10 -inch casing, with bottoms at 19 and 86.5 feet, respectively, were in turn drilled, cased, and then tightly cemented to the formation. Originally, the &-inch casing was planned to extend to a depth of 250 to 300 feet, but heaving conditions stopped this casing at a depth of 187 feet. The 8 -inch casing was also cemented to the formation. A 7 -7/9 -inch drill bit was used inside the 8 -inch casing to drill to an intended depth of about 1000 feet. In spite of the use of heavy drilling mud and special precautions, caving conditions persisited at several depths in this hole. After considerable delays, it was decided to condition the hole and set 6 -inch casing at a depth of 890 feet. This depth was never achieved, however. At a depth of 881 feet on July 13, a cobble apparently caved into the drill hole completely locking in the drilling bit at the bottom of the hole. After several shifts of concerted effort to free the drill stem, it was decided to move the drill rig to the third well site, MI -1, while options on how to proceed with PS -4 and the drilling contract were reviewed. Well MI -1 was completed in 3-1/2 days (see Subsection 3.5 below), and the drill rig was brought back and repositioned over well PS -4. Further attempts to free the drill stem were unsuccessful. Finally, excessive torque twisted off the drill pipe near bottom. On July 23, the decision was made jointly by DEPD and WCC to leave PS -4 in its present condition--uncased below a depth of 187.4 feet and with 70 feet of drill 17 0 WoodwallydeCOMRdtwft stem locked in the formation on bottom (see Figure 7). A 10 -inch gate valve was bolted on the PS -4 casing head, and the drill rig was moved to the site of well PS -5. The principal problem in the drilling and casing of well PS -4 resulted from conditions beyond the control of the drilling crew and project management. Normally, when drilling in heaving formations such as at PS -4, the hole is drilled considerably larger than the intended casing diameter. Thus, to set a deep section of 8 -inch casing under these conditions, an 11 -inch or even a 13 -inch open hole would be drilled to allow for some heave of the formation into the hole, as compared to the 9 -7/8 -inch hole drilled at PS -4. Also, after heaving conditions were known to exist, 6 -inch casing would normally call for a 9 -7/8 -inch or larger hole, instead of the 7 -7/8 -inch hole available at PS -4. On the Pilgrim Springs project, the tolerance between the casing diameter and the size of the drilled hole was determined months earlier, before the casing was purchased and shipped. These decisions, in turn, were determined by the size of drill rig that could be mobilized in Pilgrim Springs, and the number of casing size reduc- tions deemed necessary to properly case and cement a deep geothermal well of high pressure and temperature. 3.4 WELL PS -5 When drilling problems were encountered in well PS -4 and the project contract was modified to include the drilling of a fourth well, a location for the fourth well was mutually agreed upon by DEPD and WCC. This location was selected to test the possibility of the intersection of the radar lineaments of Turner (Figure 3) as the locus of rising hot water from deep sources. Both the shallow thermal contours (Figure 3) and the soil -helium concentrations (Figure 5) suggested that this might be the case. A 1000 -foot production well at this site was stipulated in the amended contract by DEPD. Because a large marsh surrounded the area of actual lineament intersection, the well site was moved a few feet south and east of coordinate 5005/200W in order to achieve more suitable ground for drilling. The drilling and casing of well PS -5 progressed smoothly, particularly in the upper 500 feet. , The drilling of this well was begun on July 23 and completed six days later 18 iw.a.ayde CorwAdtants at a depth of 1001 feet (see Figure 8 and Table 1). Problems of heaving soils into the drill hole were encountered in well PS -5, much as had been experienced at PS -4. To minimize these problems, heavier drilling mud was used, and drilling and casing times were reduced as much as possible. Because a fourth well had not been planned, no 16 -inch and little 10 -inch 'casing were available on-site for PS -5. Short lengths of 16 -inch casing were purchased in Nome and flown into Pilgrim Springs. Also, the 10 - inch casing was welded to the 8 -inch casing with a bell reducer. These were lowered in the drill hole and cemented to the formation as a single installation. Because this was the last well of the drilling project, clean-up operations and demobilization were in progress when PS -5 was properly cased and valved. The well was permitted to flow for more than 24 hours, at unrestricted rates of 30 to 60 gpm, to flush out the drilling mud and develop the well. Because of extensive cooling and drawdown effects due to the drilling and testing of this and other wells in the area, the discharge rates and temperature -profile of this well at the conclusion of its drilling were much lower than the equilibrated temperature and pressure conditions measured in late September. 3.5 WELL MI -1 The purpose for well MI -1 was to: 1) produce a significant hot-water supply on Mary's Igloo native -selection lands, and 2) evaluate the geothermal potential in the western part of the geothermal anomaly. The drill site was selected on relatively high and dry ground, within the 700C temperature contour (Figure 3), and west of the property boundary of the private lands. Drilling of well Mi -1 began on July 15 and was completed four days later at a depth of 307 feet. As shown in Figure 9, after the surface string of 16 -inch casing was set and cemented in the well, a 14 -3/4 -inch hole was drilled to a depth of 232 feet. At this point, a welded string of perforated 6 -inch, blank 8 -inch, and blank 10 -inch casing, connected with concentric bell reducers, was lowered into the open hole and cemented'to the formation. Below 232 feet, 75 feet of perforated 3 -inch casing was installed in the well. 19 N/OOi�Wdl'�•Clyde Consultants It is apparent from the construction of well MI -1 that the hot water aquifers in the 40- to 120 -foot -depth zone have been cased off and that the only water discharged from this well in its present condition are the cooler waters below 151 feet. The well was left in this condition intentionally. Because the deeper waters in this well are the coolest and lowest in dissolved solids of all waters measured in the entire Pilgrim Springs area, this well may be more valuable as a source of domestic water supply than as a source of geothermal heat. In the event that a decision is made to use well MI -1 as a geothermal well, the 8 -inch casing can easily be plugged at the 151 -foot depth, and shot perforations opened in the upper (40- to 120 -foot) heated interval. 20 4.0 GEOLOGY 4.1 GEOLOGIC SETTING NkfodwardClyde Consultants k� The Pilgrim Springs geothermal area is located about 40 miles north of Nome, Alaska, in the lowlands of the Pilgrim River Valley (Figure 10). The Pilgrim River Valley is the western extension of a probable rift valley system, which also includes the Kuzitrin Valley to the east. The Pilgrim Valley is bounded on the south by the Kigluaik Mountains, which rise abruptly from the valley floor as a north -facing escarpment developed along an active range -front fault (Turner and Forbes, 1980). This fault is seismically active and had experienced displacement in Holocene time (within the last 10,000 years). Mary's Peak and Hen and Chickens Mountain, located on a low ridge about 3 miles north of Pilgrim Springs, are composed of granitic gneisses, intrusive granites and rare amphibolites -- a composition similar to the units exposed along the Kigluaik escarpment on the south side of the valley (Turner and Forbes, 1980; Turner and others, 1981). The Kigluaik Complex appears to be a gneiss dome, and the grey paragneisses in the core have yielded a Rb -Sr isochron age of 735 million years (Bunder and others, 1977); however, the coarse-grained orthognelsses along the margin of the complex (including the gneisses on Hen and Chickens Mountain) and the intrusive granitic rocks have given Cretaceous K -Ar ages. r' Fault traces on both sides of the valley system indicate that the valley floor is relatively downthrown, but the actual amount of vertical displacement is not known. Also in doubt is the thickness of the sedimentary fill. Seismic and gravity surveys conducted by Kienle and Lockhart (Turner and Forbes, 1980) indicate that the thickness of the sedimentary fill is no less than 1500 feet. Based on previous work by Kline (Turner and Forbes, 1980) and Hopkins (1963) and drill hole data presented in this report, the valley fill includes both alluvial and glaciofluviai deposits, and possible iacustrine sands and silts. Tertiary conglomerates and sands have been mapped by Hopkins (1963) in exposures along the Kuzitrin River, 21 IMOOdYVAUIWCIyde ConsuftANtS east of Pilgrim Springs. Also, Tertiary sections are known to occur in other tectonic basins or downwarps on the Seward Peninsula including McCarthy's Marsh and Death Valley in the Bendeleben Quadrangle. Therefore, it is highly probable that the lower part of the valley fill under Pilgrim Springs includes Tertiary sediments. The possible presence of Tertiary sedimentary rocks at Pilgrim Springs is important to subsurface geothermal models of the site, as warm sodium chloride type briney water has been recovered from Tertiary sands in test wells near Kotzebue and Cape Espenberg (Nimiuk No. 1 and Cape Espenberg No. 1, drilled by Chevron Oil Co., under an agreement with Northwest Alaska Native Association). The chemistry of these waters is similar to that discharged from Pilgrim Springs and from wells` penetrating the shallow aquifer underlying the springs, as determined from analyzed dissolved constituents. Although no reliable downhole heat flow data are yet available for the Seward Peninsula, the anomalously high uranium -thorium content of the crystalline basement rocks that underlie the region suggest that the geothermal gradient may contain a significant increment of radiogenic heat (Forbes, 1980). Crystalline basement rocks underlying the sedimentary fill of the Pilgrim River Valley should be similar to those exposed along the Kigluaik escarpment and the hills to the north. No doubt these rocks also contain abnormally high concentrations of uranium and thorium. Basaltic volcanism, probably associated with tensional tectonics and rifting, has produced vents and basalt fields in the Imuruk Lake and Agiapuk areas, east and west of Pilgrim Springs, respectively. Basaltic volcanism began about 30 million years ago (Kugruk Series, Imuruk area) and has continued up to the present, as demonstrated by the Lost Jim Cone and associated tholeiitic flows that erupted a few thousand years ago (Turner and others, 1981; Hopkins, 1963). According to Turner and others, the basalt flows north of Teller (Agiapuk field) were erupted about 2-1/2 million years ago. Although recent basalt flows and vents do not occur in the immediate vicinity of Pilgrim Springs, the possibility of subsurface emplacement of basaltic magma in the valley fill section should be considered in geothermal models. 22 0 . 4.2 PREVIOUS GEOLOGIC AND GEOPHYSICAL INVESTIGATIONS a> Prior to the reconnaissance of Forbes and others in 1974, Pilgrim Springs had been classified as a Known Geothermal Resource Area by the Department of Interior, but assessments of the geothermal potential of the Pilgrim Springs system had been restricted to estimated reservoir temperatures based on chemical geothermometry. Thermal spring water temperatures had been used in the calculations, as measured in upwelling pools at the surface. According to the earlier work of Waring (1917) and Miller and others, (1975), the maximum measured spring water temperatures were about 600C. Upon examination of photography of snow melt during the early stages of break-up in the Pilgrim Springs area, Forbes and his associates at the Geophysical Institute, University of Alaska, made to a most interesting discovery. It was apparent that the total area of unseasonably warm ground in the vicinity of the springs exceeded the warming effect that could be explained by several small conduits of hot spring water emerging at the surface. This discovery led to the reconnaissance expedition to the Pilgrim Springs area in 1973. When Forbes and his colleagues inserted thermistor probes into the soft sediment of the surrounding areas of upwelling thermal waters, they were surprised to find these upwelling points were actually small convection cells that involved the mixing of much hotter saline water from a source at depth and ground water from the thawed layer near the surface. This discovery clearly disqualified any dependence upon estimated reservoir temperatures based on geothermometric calculations derived from the chemistry of spring water samples. A subsequent perusal of Landsat imagery confirmed the large area of abnormally warm ground around Pilgirm Springs. This lead to the decision to further explore the Pilgrim Springs system. These early studies lead to the subsequent field research projects of the Geophysical Institute, University of Alaska, and the most recent drilling and testing program by private contract, which is the subject of this report. 23 Woodwani-Clyde Conadtants 4.3 GEOLOGIC CONDITIONS IN THE WELL FIELD The most detailed information available on the Pilgrim Springs geology consists of data obtained from the six test wells drilled within the thermally disturbed zone (see Figure 3). Two wells, PS -1 and PS -2, were drilled and cased in 1979 and perforated in June 1982. The remaining four wells, PS -3, PS -4, PS -5 and MI -1, were drilled, cased and perforated in the summer of 1982. During the drilling of wells PS -I and PS -2, drill cuttings and drive samples were inspected and recorded on drilling logs (see Kline, 1980). The drillers were unable to obtain any drive samples below about 100 feet because of the high density and induration of sediments. The remainder of PS -1 and PS -2 were logged to total depths of 160 and 150 feet, respectively, by inspecting cutting samples collected at 5 -foot intervals. The 1982 drilling program did not call for core sampling. Instead, a geologist's log for each test hole was prepared based on drill cuttings collected at 5 -foot intervals (see Appendix B for summarized field logs and Figure 11 for a generalized geologic log). The maximum depth penetrated during the 1982 investigation was 1,001 feet in PS -5. A core barrel was used briefly in PS -4 to collect core samples in the interval between 85 and 95 feet below surface. These samples were submitted to the University of Alaska Petroleum Engineering Department for permeability and porosity analyses. The results of these tests are discussed below. Geophysical logs were scheduled for each of the Pilgrim Springs boreholes to aid in the geologic interpretations of the geothermal reservoir system. These logs usually prove useful in the evaluation of stratigraphy, formation thicknesses, and water - quality changes (particularly salinity), and in the correlation of stratigraphy throughout the well field. Because of the remoteness of the site and budget constraints, a portable Well Reconnaissance model geophysical logger provided by EXSCO was used at Pilgrim Springs. The equipment was operated by Vic Mittasch (EXSCO) and David Kirchner (WCC). 24 With the Well Reconnaissance equipment, the following logs can normally be obtained: single -point resistance (RES) and spontaneous potential (SP) in open or uncased holes, and natural gamma radiation in either open or cased holes. Because of caving borehole conditions in most of the boreholes, and the eventual loss of the downhole geophysical probe in well PS -4, the desired logs for several of the boreholes were not obtained. In fact, SP and RES logs were obtained only for most of the depth of borehole PS -3, and gamma logs were obtained only in boreholes PS -3 and PS -4. Attempts to procure downhole equipment to replace the equipment lost in PS - 4 were not in time for the logging of boreholes MI -1 and PS -5. Table 2 gives a summary of the geophysical logs obtained from the Pilgrim Springs boreholes. Copies of the geophysical logs obtained from PS -3 and PS -4 are included in Appendix B. In general, for the logs obtained from PS -3 and PS -4, their use was for qualitative rather than quantitative interpretations. Absolute formation parameters, such as porosity, permeability and water saturation, cannot be calculated from logs of the Weil Reconnaissance logger. Relative changes in these parameters can be obtained from these logs, however. Because only two of the six boreholes at Pilgrim Springs were logged with this equipment, a correlation of geologic formations throughout the well field or even between wells PS -3 and PS -4 was not possible. The SP and RES logs of borehole PS -3 were most useful for estimating formation characteristics. From the RES logs, two zones of high permeability are suggested, one 8 feet thick from 67 to 75 feet below land surface; the second 15 feet thick from 167 to 182 feet below land surface. Based on evaluations of drilling data collected in 1979 (Kline, 1980) and in 1982 and on interpretations presented in earlier reports (Turner and Forbes, 1980; Wescott and Turner, 1981), the following generalizations can be made about the sediments in the Pilgrim Springs area. The sediments in the upper 1000 feet of the thermally disturbed part of the valley are fluvial and glaciofluvial deposits. They were deposited by the ancient Pilgrim River and its tributaries, which meandered across the valley during the Quaternary 25 Clyde CorwAdtants and possibly the Tertiary periods. The deposits include channel, floodplain, and overbank deposits. The channel deposits include fine- to coarse-grained sand, gravel and conglomerate units that were probably deposited in paleochannels and point bars. The sediments typically coarsened downward, as evidenced by visual inspection of cuttings, core samples, and the SP and RES logs. These sediments are characterized by the typical "salt and pepper" appearance as described by Kline (1980). Visual inspection of drill cuttings revealed that the valley alluvium is composed predominantly of quartz grains and fragments of dark -colored slate and phylite. Pyrite is abundant in some depth zones, suggesting anthigenic formation in a geothermal environment. Biotite was also abundant at some depths. The subrounded to rounded shapes of the pebbles and cobbles in the coarse-grained gravels and conglomerates are indicative of reworked stream channel deposits. Fine-grained silty sand and clayey silts are abundant through the entire penetrated section. The finer -grained deposits are indicative of floodplain and overbank deposits. Two individual core runs were made in PS -4 in the interval between 85 and 95 feet below ground surface. Following is a field description of those core samples: s Depth Field (feet) Description 85 to 87 lost core 87 to 87.5 Sandstone, grey, fine- to medium -grained; moderately well sorted, faintly bedded, relatively high porosity and r permeability. Composed of predominantly subangular quartz, with biotite, muscovite, garnet(?). Friable to moderately well cemented. Matrix material is silt. 87.5 to 89.3 Same as above, but very fine-grained to fine-grained; high porosity and permeability. 89.3 to 90.0 Sandy siltstone, light grey to greyish brown; very fine- grained; friable to moderately cemented. 26 �DOdWAI"i�-CWe CoRSUftnts Depth Field (feet) Description 90-94 Sandstone (as at 87.5) but medium- to coarse-grained. 94-95 Sandstone -Conglomerate grey to black, pebble conglomerate in medium -grained subangular sandstone matrix; pebbles to 3/4 -inch, coarsens downward; pebbles are subangular quartz, quartzite(?) and argillite(?). Friable to poorly cemented. (None of the samples in this 85- to 95 -foot interval effervessed with dilute HCl.) Mineralogical and hydraulic tests were performed by the Petroleum Engineering Department of the University of Alaska at Fairbanks (written communication, Christine Ehli g-Econom idles, August 3, 1982). Analyses were performed on PS -4 core samples collected from the 90- to 95 -foot interval. The results of x-ray diffraction analyses revealed the major constituents to be quartz with minor amounts of muscovite and traces of calcite. Kline (1980) presents a good description of mineralogy in his report. Based on field examination, the only physical evidence of hydrothermal mobilization and redeposition of silica was observed in a sandstone encountered in PS -4 at 868 feet below ground surface. Translucent to opaque SiO2 cement was observed between individual sand grains in fragments of the sandstone. A significant decrease in drilling rate was observed from 868 feet to a total depth of 881 feet. Other zones of cementation and/or hydrothermally altered intervals may have been encountered at shallower depths as evidenced by slow drilling rates. However, the drilling techniques employed during this investigation made it virtually impossible to obtain representative undisturbed samples. It is likely that if a continuous core had been obtained from the section, other hydrothermally cemented zones might have been identified. During the lithologic logging of wells PS -3 and PS -4, a small magnet was used to assess if any magnetite were present in the cuttings. Based on visual observation and the magnet procedure, no magnetite was detected in any of the samples. The pyrite, which was abundant in well-defined zones in all of the 1982 wells and frequently 27 • Woodward-ayd@ Col' sukantS exhibited large euhedral crystals, is a common indicator of geothermal conditions and was so considered in the log interpretations. The results of the hydraulic testing by the University of Alaska on selected core samples between 90 to 95 feet showed values of porosity that ranged from 24 to 39.6 percent. The permeability values of one sandstone plug, reported in Darcy units for both vertical and horizontal directions, were 0.0025 and 0.0051, respectively. Based on these laboratory permeability tests, inspection of drill cuttings and core samples, SP and RES logs, and temperature and flow data, it appears that the most likely zones contributing significant amounts of water to wells are from 65 to 75 feet and from 167 to 182 feet below ground surface. Additional field studies would be necessary to verify that these intervals are the producing zones. If complete geophysical logs of each of the boreholes had been available, other likely producing zones might have been identified. 28 5.0 WELL TESTING 5.1 INTRODUCTION WOOd1Nd1 ' e Consuitant5 Four types of well -test data were collected during the testing of the geothermal wells at Pilgrim Springs. These included: 1) pressure -interference effects among wells, 2) geochemistry of the well -discharge waters, 3) temperature gradient and hydrothermal tests, and 4) hydraulic tests to evaluate reservoir -system parameters. Although many sets of test data were recorded during the actual drilling of each of the wells, for the most part, these represented transient conditions and provided little precise interpretive value. The test data of most value in assessing the characteristics of the reservoir system were generally collected either during the initial stages of drilling, before fluid circulation in the well began, or after the well was completed and formation fluid pressures and temperatures were equilibrated to undisturbed conditions. A discussion of the results of the above tests are included in the following sections. Interpretive results of these tests are graphically presented In Figures 12 through 25, and in tabular form in Appendices C and D. 5.2 INTERFERENCE EFFECTS AMONG WELLS Throughout the drilling and testing program, numerous short-term interference tests among the completed wells were conducted. In these tests, the pressure head in one or more shut-in observation wells was closely monitored to detect possible drawdown interferences when a nearby discharge well was opened. Because all six wells at Pilgrim Springs are artesian and close together, drawdown effects among nearby wells of the same depth should occur quite rapidly. In general, distinct well interferences were measured between wells PS -1 and PS -2, both when PS -1 was the flowing well and when PS -2 was the flowing well. Drawdown interferences between wells PS -1 or PS -2 and other wells and among the 1982 wells themselves were more subtle because of greater distances and a difference in depth 29 Woodward-Oyde Consukants of the well perforations. This suggests that a series of horizontal aquitards effectively separate wells of different depths in the cluster. As discussed in Sections 4.3 and 5.5 below and as suggested in Figure 20, the pressure and temperature of ground water are depth -related throughout the well field. Intimate interferences are thus expected among wells perforated in the same depth zone, and less intimate effects should occur in wells of different depth zones. Data from a typical interference test, in which shut-in pressures in PS -2 were recorded while PS -1 was flowing, are shown below: Time(a) Pressure Time Pressure (minutes) (psig) (minutes) (psig) 0 3.5 20 1.6 8 2.9 22 1.5 12 2.4 24 1.3 14 2.3 27 1.1 16 2.1 29 1.0 17 2.0 30 0.9 18 1.9 31 0.8 (a) Time since PS -1 was opened; flow rate at 30 to 35 gpm As shown, 6.2 feet of water -level decline (2.7 psig) occurred in well PS -2 about 31 minutes after PS -1 was opened and permitted to flow at a rate of 30 to 35 gpm. From these test data, an aquifer system permeability of 90 gpd/ft2 (4.5 Darcys) was estimated for the hot-water zone tapped by these two wells (Economides and others, 1982). 5.3 GEOCHEMISTRY OF WELL WATERS Months before the Pilgrim Springs project began, assistance was requested by M.A. Moorman of the Alaska Division of Geological and Geophysical Survey in making geochemical studies of water and gas from the six geothermal wells at Pilgrim Springs. In response to this request, access to the wells and other support assistance 30 Woodward -Clyde Consultants were provided. As the drilling and testing progressed, Moorman collected and evaluated numerous samples in the field. Some of the analytical work was completed at the well site, other required the preparation and shipment of samples to Fairbanks for laboratory testing. Since DGGS assumed responsibility to analyze the well waters for common constituents, no duplication of this effort was undertaken by WCC. Table 3 gives the preliminary results of chemical analyses of water samples collected from wells and springs at Pilgrim Springs. Samples were collected and analyzed by M.A. Moorman of the Alaska Division of Geological and Geophysical Surveys. For a comprehensive interpretive analysis of the geochemistry and physical characteristics of these Pilgrim Springs waters, see Moorman and others (1983). As shown in Table 3, the geochemistry of waters from wells PS -1 and PS -2 are uniformly hot, low in salinity, of low pH, and high in total dissolved solids. Well MI -1, which is perforated below the shallow thermal aquifer, is cool, low in salinity and dissolved solids, and of high pH. Wells PS -3, PS -4 and PS -5, each perforated below the thermal aquifer, are mostly intermediate between these two extremes. For comparative purposes, a series of specific conductance measurements of well and surface waters were made on July 17, 1982 by WCC. Two weeks later, well PS -5 was completed and its conductivity measurement was added to the list. On the conductivity scale of the meter used, one micromho per centimeter equals roughly 0.7 parts per million (ppm) of total dissolved solids. The results of these measurements, uncorrected for temperature differences, are as follows: 31 Approximate Conductivity Total Dissolved Solids Source (micromhos per centimeter) (parts per million) Pilgrim River, east of Church 150 100 Pilgrim Springs Spa 12,000 8,400 PS -1 13,000 9,100 PS -2 9,500 6,600 PS -3 4,100 2,900 PS -4 270 190 PS -5 1,100 800 MI -I 300 210 31 Woodward -Clyde Consultants As with pressure and temperature, the quality of ground water throughout the area seems to be controlled largely by depth, with high-temperature shallow waters (less than 150 feet deep) being high in total dissolved solids, and the deeper cool waters being low in total dissolved solids. If this is the case, Pilgrim Springs is probably recharged from the same shallow aquifer system as tapped by well PS -1. Significant quantities of hydrogen sulfide gas are released to the atmosphere when hot waters of the shallow thermal aquifer system are permitted to flow from either wells or springs. Hydrogen sulfide can be dangerous to human health at A concentrations above 20 ppm for 15 minutes and flammable at concentrations above 4.3 percent. Under most outdoor conditions at Pilgrim Springs, concentrations of hydrogen sulfide should present no problems. Those working around wells discharging thermal waters should be fully aware of problems that might occur. Using an air sampling tube, hydrogen sulfide vapors from well PS -2 were measured at 7 ppm, and from PS -3 at 1 ppm. Table 3 shows the hydrogen sulfide content of thermal waters from wells and springs to range between 2.2 and 4.4 ppm. 5.4 TEMPERATURE GRADIENTS AND PROFILES One of the characteristics of the Pilgrim Springs geothermal anomaly is the extremely high thermal gradients in surficial soils. As shown in Figure 3, soil temperatures as high as 500C to 800C at a depth of 15 feet (4.5 meters) were measured in 1979 throughout the area of geothermal drilling. While collecting soil samples for helium -concentration measurements in June 1982 (Section 2.6), several samples from a depth of 2.5 feet were noticeably very hot to the touch. High near -surface temperatures were also recorded at each of the 1982 well sites while augering with the drilling rig to set the surface string of casing. In fact. the shallow temperature gradient in well PS -3 was so high (76.700 at a depth of 17 feet that the threat of flashing -steam conditions were projected for depths too shallow to 32 VAxW Yard -Clyde Consultants control with weighted drilling mud and blow-out prevention equipment. As drilling progressed in this and each of the other wells, however, temperatures never quite reached the boiling point at any of the four sites. Following are measured soil temperatures at shallow depths in each of the four wells drilled in 1982. Each temperature was taken of soil cuttings brought to the surface on a 20 -inch auger bit, and before circulating drilling fluids were used. Also listed are temperatures extrapolated from the 1979 survey data of Figure 3. PS -4 12 Approximate 15 1982 Soil Depth Temperature Well (feet) (oC) PS -3 15 70.0` 17 76.7 PS -4 12 53.3 15 65.0` 18 75.6 PS -5 1 27.8 2 33.3 4 38.3 7 42.2 10 52.2 15 68.9 MI -1 6 40.0 12 60.0 15 67.0` 16 68.9 19 71.1 Extrapolation from Figure 12 1979 Soil Temperature (OC at 15 feet) 80+ 65+ 65+ 70+ Figure 12 is a graphical plot of the above shallow soil -temperature data. The temperature curve of MI -1 shows perturbations in the data below 15 feet, and the curve for PS -5 suggests temperature disturbances above 5 feet. The apparent decrease in thermal gradient below 15 feet in MI -i is probably due to caving conditions and mixing of formation temperatures in the uncased hole below the water 33 Woodward -Clyde Consultants table. The abrupt departure of the PS -5 temperature curve from the straight line above 5 feet is probably caused by the recent flooding of an extensive nearby marsh by the influx of well water from PS -4. A generalization of the shallow gradients of Figure 12 suggests that throughout the 1982 drilling area, the near -surface thermal gradient is about 700C per 20 feet of thickness. This rate calculates to 3500C per 100 feet of depth (or more than 300 times a normal thermal gradient). This was the reason for concern that "blow-out" conditions might develop at several of the well sites before blow-out prevention equipment could be installed. Numerous measurements of drilling fluid inflow and outflow temperatures were recorded as the drilling of each well progressed. For the most part, these represented transient conditions with little interpretive value. Even at the conclusion of the drilling and testing program, it was apparent that static temperatures and pressures in the wells were still adjusting to undisturbed conditions. In order to get equilibrated temperature and pressure data for the well field, it was necessary to schedule a return trip to Pilgrim Springs in late September 1982, six weeks after the drilling and testing programs were completed. The solid curves of Figures 13 through 18 show the temperature profile of each of the six geothermal wells under no -flow conditions, as measured on September 25 through 27, 1982. These profiles are plotted from precise downhole measurements of the water column in each well, as measured at selected depths with a FENWAL model UUT-31J1 thermister instrument. Although the absolute accuracy of this instrument is probably not closer than loC, the differential accuracy during a series of measurements is probably closer than 0.020C. There is a serious question, however, as to how accurately the measured water temperatures represent formation temperatures outside the casing at the same depths. Because of thermal convection in the well casing, especially in the upper 100 feet of depth where colder, heavier water overlies the warm, light water, measured temperatures may be somewhat less than true values in the formations. The dashed curve of Figures 13 through 18 represents a corresponding temperature profile under flow conditions, in which evidence of possible zones of either hot or cold influx to the well are sought. Temperature data for the September 25-27 surveys are tabulated in Appendix C. 34 The degree of possible thermal mixing due to convection that may have occurred in each of the wells prior to their temperature profiles of September 25-27 is suggested in the comparison of shallow soil temperatures with water temperatures inside the casing. As shown in Figure 13, the 1979'soi1 temperature of well PS -1 at a depth of 15 feet (4.5 meters) wat about 630C (Figure 3), which is almost exactly the temperature of the equilibrated well water at this depth in September 1982. This suggests very little thermal mixing occurring in the well casing. In well PS -2, however, the September 1982 shut-in water temperature (Figure 14) at a depth of 15 feet was more than 70C cooler than the 1979 soil temperature at this same depth. This suggests that significant mixing due to convection is continuing in well PS -2. A similar analysis of the four 1982 wells, comparing 1982 shallow soil temperatures (Figure 12) with water temperatures of corresponding depth, indicates that little thermal mixing is occurring in well PS -3 (Figure 15), and considerable thermal mixing is occurring in wells PS -4 (Figure 16), PS -5 (Figure 17), and MI -1 (Figure 18). Note that since wells PS -1 and PS -2 (Table 1) are perforated only in the high- temperature depth zone, the flowing water temperatures remained high throughout the effective well depth (Figures 13 and 14). In a similar way, the temperature of flowing water in the other four wells reflect the cool temperatures of their formation source, and are only slightly warmed in passing upward through the shallow thermal aquifer system. Figure 19 shows a correlation of the static temperature profiles of the six wells (Figures 13 through 18). All wells apparently conform to the same hydrothermal reservoir model, as evidenced from: 1) a gradual trend of increasing temperatures from the surface to a maximum high-temperature zone at a depth of 65 to 80 feet; 2) a rapid temperature decrease to roughly surface temperatures at a depth of 150 to 250 feet; and followed by 3) what appears to be an independent thermal gradient related to a heat source at depth. Two types of heat transfer are suggested from the curves of Figure 19: 1) horizontal movement of ground water at shallow depth, which transfers heat from an undefined shallow heat source area throughout the well -field hot spring area and which is kid wOO�IYI/dnl-ClYde Consultants responsible for the high temperatures above a depth of about 200 feet; and 2) a conductive heat that is transferred vertically upward from an undefined underlying heat source. Even though the temperatures of PS -4 are about 180C higher than those of PS -5 between the 250- to 500 -foot depth, both have a gradient of about 2.20C per 100 feet. This gradient is about two-times the normal temperature gradient of a non -geothermal area and confirms earlier conclusions of Wescott and others (Turner and Forbes, 1980) that were based on geophysical studies. There is little evidence from the 1982 data to indicate the direction of either the ground -water flow or the heat source for the circulating water in the shallow, high- temperature aquifer system. The static heads in the six geothermal wells provide no clue, since the differences in artesian heads are affected largely by the depth of the well (Figure 20). Maximum temperatures in the 60- to 90 -foot depth zone for the six geothermal wells (Figure 19) show a general increase northward, suggesting that the geothermal source of heat for this shallow reservoir might be located somewhere north of the well field. This may be a significant indicator. The wells with the higher temperatures (PS -1 and PS -2), however, have a 4 -inch casing inside 6 -inch casing, and probably have less thermal convection in the well. These temperature gradients are inconclusive. 5.5 EVALUATION OF RESERVOIR PARAMETERS Numerous flow tests of the Pilgrim Springs geothermal wells were performed to calculate the hydraulic characteristics of the geothermal reservoir system. These tests also were used to evaluate the production characteristics of the wells. Most of the tests were performed by maintaining a constant discharge of an individual well and measuring the change in head in that well and surrounding observation wells. Head changes in these wells were then usually measured for a brief time after the flowing well was shut-in. Most of the tests were run from 2 to 6 hours, which is "sufficient for analysis of drawdown data from the flowing well. In some cases, the tests were run at two rates of flow; information from these "step" tests can aid in the evaluation of production characteristics of individual wells. Each of the six geothermal wells was tested at least once, and all wells had heads above land surface throughout the testing period. 36 • 0 Woodward -Clyde Consultants Evaluating the hydraulic characteristics of saturated sediments normally involves the determination of two parameters: 1) transmissivity (T), which equals the hydraulic conductivity times the saturated thickness of the aquifer system; and 2) storage coefficient (5). Transmissivity is a measure of the ability of the formation to transmit ground water; the storage coefficient is a measure of the ability of the rock to store (and then release) ground water. Most of the aquifer tests at Pilgrim Springs involved measurements of water -leve! changes in the discharge well only, because observation wells of the same depth generally do not exist. Interpretations from recording only head changes in the production well tests gave fairly reliable estimates of T, but not of S. The data were plotted on semi -logarithmic paper (drawdown versus time plots) and analyzed by a common straight-line technique (Cooper and Jacob, 1946). A similar plot and analysis of recovery data can be made of water -level data from the production well after the discharge has stopped. Another technique of calculating transmissivity was used when the amount of test data was insufficient for the straight-line calculations. If only the discharge rate (Q), total drawdown (A) in the discharge well, and length of time (T) of the constant discharge test are known, then a method first developed by Theis (and published by Ferris and others, 1962) was used to estimate T. Generally, the reliablity of this estimate is less than that obtained from the straight-line analysis. In only one instance were calculations of drawdown effects in an observation well used (Economides and others, 1982). Analysis of Data The hydraulic -test data collected during the six-week field investigation were reviewed and evaluated in terms of completeness and quality. Much of the test data was not analyzed because: length of test was too short; little or no water -level data were obtained from the flowing well; more than one well was flowing during a test; and observation wells had variable completion depths. All the data that appeared useful were analyzed using the drawdown data from the flowing well itself. Some of these analyses are still affected by unexplainable deviations of water -level data, possible partial penetration of previously tested wells, possible interference from the recovery of previously tested wells, and insufficient time period for flow tests and measurement of recovery. From the test data that were analyzed, moderately W 1Na1'd-Clyde Conadtants reliable estimates of T were obtained. These estimates are summarized in Table 4. No estimates of S were made during the study. All data used in the analysis are tabulated in Appendix D. Well PS -1 - As discussed in Section 5.4, an interference test was run on well PS -1. This test provided the data for calculating aquifer -system parameters. With PS -1 flowing at a constant rate of 30 to 35 gpm, the static -water level was recorded (Economides and others, 1982). A log -log graph of water -level declines versus time was analyzed by type curve matching, from which a permeability of 4.5 Darcys was calculated (Economidies and others, 1982, pages 4 to 5). From the above, a hydraulic conductivity of the thermal aquifer system in the vicinity of well PS -1 was calculated to be 90 gpd/ft2. Assuming a 40 -foot effective thickness for the aquifer system, the formation transmissivity would be about 3600 gpd/ft. Well PS -2 - A flow test was performed on well PS -2 on July 1-3, 1982, from which a rough approximation of formation transmissivity has been calculated. During the test, the flow rate ranged from 40.6 gpm to less than 25 gpm after 800 minutes (Appendix Table E-1, p. 2), after which the valve was regulated to maintain a flow of about 36 gpm until the end of test at 3518 minutes. Figure 21 is a semi -logarithmic plot of the head (or drawdown) verses time for PS -2, the flowing well. A straight line analysis (Cooper and Jacob, 1946) was applied to the early and late data of Figure 21 during which the discharge rate was roughly 36 gpm. From these data, a rough T -valve of 12,600 gpd/ft was obtained. Using the perforated interval of PS -2 for the thickness of the aquifer, a hydraulic conductivity of 420 gpd/ft2 was calculated. Well PS -4 - A two-step test was performed on well PS -4 on July 23, 1982. The flow rate averaged about 50 gpm for the first 226 minutes and then was stepped up to 120 gpm for the final 146 minutes of the test. Figure 22 is a semi -logarithmic plot of head versus time data for PS -4 for the first step of the test. The second test did not contribute to the analysis. Straight-line analysis was applied to the data from 20 to 200 minutes; a T -value of 41,000 gpd/ft was obtained. Using the total 38 U Woodward -Clyde Consultants open borehole of PS -4 for the thickness of the deposits tested, a hydraulic conductivity was calculated at 60 gpd/ft2. Head levels were also measured in PS -1, PS -2, PS -3, and MI -1; the data were not analyzed because the observation wells were only partially completed in the zone open to PS -4. The effect of this partial penetration can be seen in the data by noting that PS -3 and Ml -1 had an equal amount of head change, although their respective distances from PS -4 are quite different. Generally, the data from the observation wells were sparse and showed only slight effects when PS -4 was flowing. Well MI -I - On July 25, 1982, a two-step flow test was performed on MI4. The first step lasted for 70 minutes and had a recorded flow rate of 21 gpm; the second step was 102 minutes long and had a flow rate of 75 gpm. Figure 23 is a semi -logarithmic plot of head versus time for the flowing well MI -1. The first step shows a very good linear trend and indicates a T -value of 2500 gpd/ft. MI -1 is completed over 156 feet; a hydraulic conductivity of 16 gpd/ft2 was calculated. Data were not collected from any of the nearby observation wells during this test. Recovery data from MI -I were not analyzed because the test was conducted in two steps. Well PS -3 - A two-step flow test was performed on well PS -3 on July 27, 1982. The test was conducted at a flow rate of 21 gpm for 61 minutes and at a rate of 43 gpm for 99 minutes. Figure 24 shows a semi -logarithmic plot of head versus time for PS - 3 for the first step. Although the first constant flow step is rather short, a straight- line segment of the data was identified between 5 and 25 minutes (the leveling off of the data at from 40 to 60 minutes is unexplained). The Jacob analysis provided a T - value of about 2000 gpd/ft. A hydraulic conductivity of about 20 gpd/ft2 is calculated using a tested interval of 93 feet. Well PS -5 - A test was performed on PS -5 on September 27, 1982. Unlike the other tests described above, this test involved maintaining a constant head while the well was allowed to flow freely. This is accomplished simply by instantaneously opening a shut-in well to a pre -arranged setting. The head above the discharge point is instantaneously lowered to zero (if referenced to the discharge point), and the discharge decreases in a non-linear fashion with time. Figure 25 is a semi - logarithmic plot of discharge versus time for a constant head test performed on 39 WbodwardeC1ydeConadtan#$ PS -5. The analysis performed on the data involves a straight-line fit to the data and the use of a similar equation applied in the Jacob analysis (Jacob and Lohman, 1952). The analysis gave a T -value of 320 gpd/ft and a hydraulic conductivity of 0.82 gpd/ft2 (assuming a tested interval of 393 feet). These results should be considered as fairly approximate because of the relatively short length of the test and sparse data. Conclusions Numerous data were available for analysis to evaluate the hydraulic characteristics of the deposits at the Pilgrim Springs site. The data were reviewed and those thought to be beneficial for standard analysis were reduced, plotted and analyzed. Since none of the wells were adequately developed prior to testing, the analyses provide only very rough estimates of transmissivity for the areas tested. Two types of data analyses were used in this study. These involved: 1) straight-line analysis of semi -logarithmic plots of head (drawdown) of the flowing well versus time data for the first step of flow tests, or after about 4 hours of constant discharge; and 2) derivation of T from the specific capacity data (Q/s) of the flowing well during the first step fo the flow tests. Estimates of hydraulic conductivity were made assuming that the saturated thickness of the aquifer system tested was equal to the perforated or open interval of the well casing. Table 4 shows that the near -surface deposits (less than 100 -foot depth) have the highest hydraulic conductivity (700 gpd/ft2), while deposits at a depth of 150 to 300 feet show more than an order of magnitude less permeability (about 20 gpd/ft2). The results are variable for the permeability of the deposits at greater depths. For example, well PS -5, which was perforated from 588 to 981 feet, gave a K of 0.82 gpd/ft2, while well PS -4, which was open from 187 to 881 feet, gave a K of 60 gpd/ft2 (two orders of magnitude greater). This difference could be from the large open interval of these two wells. Better estimates of T and K would be obtained if the production well were completed in a more limited zone. 40 0 • . 6i . 6.0 SURFACE HYDROLOGY As indicated in Figure 10, the sloughs that drain the thermal seeps and springs of the Pilgrim Springs area are in close proximity to the geothermal well field. These sloughs, flowing southward on the east and west of the well field, eventually flow westward to join Pilgrim River some 6 or 8 miles downstream from the well field. The spring discharge into the sloughs is relatively hot and of high conductivity and is apparently intimately related to the shallow high-temperature aquifer system penetrated by each of the wells (Figure 19). Early in the investigation, it was assumed that the effects of well -field drawdowns would cause measurable decreases in the surface discharge of these thermal springs and seeps. Accordingly, two V -notch weirs were installed at the east slough and one on the west to detect possible changes in the collective flow rate. Water conducti- vity was also measured at these sites to monitor possible changes in water quality related to changes in the discharge of the springs and seeps. Periodic measurements of discharge and conductivity continued from June 28 to July 21, 1982. These measured results are summarized in Table E-2 of the Appendix Volume. During the period of measurement, particularly the slough discharge varied ' considerably at each weir site. Instead of being able to identify discharge changes related to well -field drawdowns, changes were influenced principally by seasonal variations, precipitation, and probably barometric fluctuations. The direct effect of these influences, in turn, were largely masked by delayed changes in bank storage. No measureable interference effects of decreased spring and seep discharge caused by, well -field drawdowns were recorded. During the period of observation, the flow in the east slough past the well field, due predominantly to spring and seep inflow, varied from about 0.1 cubic foot per second (cfs) in early July to about 0.03 cfs in late July. Discharge in the west slough, due predominately to a few large springs west of well MI -1, decreased from about 0.5 cfs on July 1 to 0.24 cfs in mid -month, and then increased due to the large discharge of well MI -1 into the slough during well testing. 41 V ood CIyde ConstdtantS Although not defined during the June 1982 testing program, the spring and seep discharge in the geothermal area appears to be directly related to artesian heads in the underlying thermal aquifers. As long as wells are permitted to discharge by artesian flow only (i.e., no pumping occurs), some spring discharge will occur. However, if the discharge `of the geothermal wells is increased significantly by pumping and if the artesian heads drop below land surface throughout the shallow aquifer system, the springs and seeps of the area would most likely diminish and might eventually dry up. 42 Woodward -Clyde Consultants 7.0 RESOURCE ASSESSMENT A conceptual model of the Pilgrim Springs geothermal system was developed to integrate and explain the data collected to date from the system and to guide further data collection and analysis efforts. The conceptual model is a formal statement of our understanding of the geothermal system, and as such, is a hypothesis that explains the geothermal system. The model can be tested by collecting new information in the geothermal system. If this new information is not consistent with the hypothetical model, a new model can be formulated to explain the system and guide future data collection efforts. We feel that the model described below is realistic and provides useful estimates of the resource potential of Pilgrim Springs. System Overview This current model of the Pilgrim Springs geothermal system is graphically depicted in Figure 26. An upwelling of hot water from an unidentified deep source is one of several possible explanations to account for the geothermal system at Pilgrim Springs. As far as a quantitative assessment of the resource is concerned, the actual source mechanism is of little concern. The basic features of the assumed model are: o hot water, representing the total water and heat input to the system, rises from depth along a fracture zone or at the intersection of fracture zones; o the hot water recharges a shallow near -surface aquifer system that underlies the thawed area; and o energy discharge occurs as heat loss to the atmosphere, spring discharges and ground -water flow away from the the thawed area. A model of a geothermal flow system that will be useful for assessing resource availability must define three basic elements: 1) system boundaries, 2) boundary 43 0 • Wbodward-ClydeCawtdtants fluxes, and 3) internal system functions. Our current model of the Pilgrim Springs geothermal systems is designed to consider these three elements, as explained below. 7.1 GEOTHERMAL SYSTEM BOUNDARIES The available data suggest that the geothermal system is bound on the east, west and south by structural features possibly related to a block -faulted basement. The hottest part of the Pilgrim Springs area appears to be located at the northeastern corner of a subsided block. The escarpment on the west (Figure 1) appears to be a structural limit on the geothermal system. Based on resistivity work by Wescott and others (Turner and Forbes, 1980), permafrost west of the escarpment has a thickness estimated at over 325 feet. East of the escarpment, permafrost is less than 80 feet thick. The boundary to the north is unknown. The base of the hot-water aquifer system, which comprises the near -surface geothermal system, has been demonstrated by data collected in this study to be less than 200 feet below land surface in the vicinity of the geothermal well field (Figure 19). The geothermal system has been studied extensively only within the part of the thawed area where near -surface temperatures are the highest (Figure 3). Because little is known about the rest of the geothermal 'system, for purposes of calculating heat and water fluxes within the geothermal system, the modeled geothermal system only consists of the area within the 300C contour shown on Figure 3. The size of this area is about 2.2 x 106 ft2 (0.2 x 106 m2). 7.2 BOUNDARY FLUKES Fluxes Out of the System The discharge of energy from the modeled geothermal system (Figure 26) occurs: 1) to the atmosphere over the area within the 300C contour shown on Figure 3, 2) in water discharging from numerous small springs, 44 Vftodward-ClydeConSuftants 3) in ground water flowing away from the area, and 4) in conductive heat transfer to deeper zones. These energy discharges can be quantified with data collected in this study and data collected during earlier studies reported in Turner and Forbes (1980). The energy discharge to the atmosphere can be roughly estimated from shallow temperature gradients measured at the four wells completed in this study (Figure 3), temperature gradients measured by Harrison and Hawkins (1980), and thermal conductivities assumed from measurements by Harrison and Hawkins (1980). Based upon these data, the heat flux to the atmosphere Oa) is calculated by the following equation: Ja =KiA where: K = thermal conductivity, 2.5 W/meter - OC; i = thermal gradient, 120C/meter; A = area, 0.2 x 106 m2. Using the values shown and the above equation, Ja=6MW Water discharges from the geothermal system in a number of small springs in the thawed area. The total thermal water discharge from the springs was measured during the summer of 1979 to be about 0.15 cfs, with an energy content of 2 MW (Harrison and Hawkins , 1979). Seasonal variations in this flux are unknown, but 1982 data showed variations in water discharge from about 0.2 to 0.5 cfs (see Section 5). Osterkamp (1983, written communication) estimated that ground water flowing away. from the thermally disturbed area transports 100 MW of energy from the geothermal system. This estimate is based on measured temperature changes in the Pilgrim River in the vicinity of the thermally disturbed area, and on measured ice thickness 45 • H/Oodwar"d-ClVd@ Consukants and bottom temperature surveys in the Pilgrim River. There is no direct data to calculate directions or rates of ground -water flux away from the thermally disturbed area. A mass and energy balance of the modeled part of the geothermal system suggests that thermal ground -water flow out of this part of the system is only in the range of 1.4 to 1.8 cfs, and that the total energy flux in the ground water (referenced to 000 is in the range of 10 to 15 MW. The mass and energy balance is shown on Figure 26, and is detailed later in this section. The marked temperature reversals recorded in wells PS -3, PS -4, PS -5 and MI -1, between 100 and 200 feet below surface (Figure 19), indicate that significant heat flow occurs downward from the shallow hot-water aquifer to deeper zones. The magnitude of this heat transfer is calculated in the following manner: 3d=KiA where: id = heat flux downward, K = thermal conductivity, 2.5 W/meter - oC; i = thermal gradient, 20C/meter; A = area, 0.2 x 106 m2. Thus, id =1MW The downward temperature reversals characteristic of the shallow thermal aquifer system (Figure 19) indicate that either: (a) the Pilgrim Springs geothermal system is relatively young and the temperature difference between the deep source and the 100 -foot depth are not yet equilibrated (see Bodvarsson and others, 1982, for a discussion of time required to achieve equilibrium); or (b) ground -water flow out of the geothermal area in a zone between 150 and 250 feet below land surface acts as a thermal sink. 46 WoodWar&Cl /de CN1S Monts There may be some flow of cooler ground waters from the deeper zones to the shallow hot water aquifer, based on an upward hydraulic gradient of about 0.05 that exists between the depths of 100 and 200 feet below land surface. The magnitude of vertical ground -water flow can not be directly calculated because the vertical hydraulic conductivities are unknown. However, nearly linear temperature profiles measured between 100 and 200 feet below land surface (Figure 19) indicate that the upward ground -water flow is probably small (Bredehoeft and Papadopolous, 1966). Fluxes into the System According to the conceptual model of Figure 26, the Pilgrim Springs geothermal system is likely a fault -charged reservoir of the type described by Bodvarsson and others (1982). In this system, energy and mass transfer occur from an deep source to the shallow aquifer along a fracture system or at the intersection of two fracture systems. At Pilgrim Springs, the depth and temperature of the hot water source are not known. Economides and others (1982) estimated a source depth of about 5,000 feet below land surface, and a source temperature of 15000 by extrapolating temperature gradients from PS -4 and PS -5. The observed field data also can be achieved with a source temperature of about 1000C, which is just greater than measured Pilgrim Springs temperatures, and a source depth of about 2,000 feet. A probable source of thermal energy is deep circulation of ground water from fractured bedrock. Alluvial and fluvial sediments overlie the basement rocks, which may occur more than 1,700 feet below land surface (Kienle and Lockhart, 1980). The alluvial sediments may be intruded by recent volcanics (Forbes, 1982, personal communication). Possible sources of water to the system may be recharge from alluvial fans from the Kigluaik Mountains, infiltration along fault zones on the margin of the Kigluaik Mountains, direct recharge to the thermally disturbed area, or recharge from the river. Osterkamp and others (1980) suggest that recharge from the mountains is not likely because these mountainous areas are probably underlain by permanently frozen ground. The artesian heads as high as 15 feet above land surface in aquifers 300 feet deep require recharge from areas considerably higher than Pilgrim springs. 47 0 7.3 INTERNAL SYSTEM FUNCTIONS 0 WOOdWard- Corm*ants Convective heat transfer has been determined by Osterkamp and others (1980) to be significant in the upper 20 feet of the soil in the thawed area. The 1982 temperature data suggest that convective' heat transfer may be the dominant mechanism for transfering heat from the highly permeable aquifer (at a depth of 80 to 100 feet) to land surface. Based on data shown in Figure 12 and the soil -temperature plots of Figures 13 through 18, the actual temperatures are estimated to be relatively uniform between about 20 and 100 feet below land surface. The relative uniform temperatures result from convective heat transport upward. Horizontal heat transport in the shallow hot water aquifer is assumed to occur primarily as convective transport in ground water that moves radially away from an assumed fracture source. Depending on the distance from the source, the temperature of water in the shallow reservoir system may be as low as 100oC at the hottest spot. At the boundary of the modeled area, no vertical temperature profiles exist; however, based on an extrapolation of existing data, it is probable that maximum ground -water temperatures are in the range of 600C to 700C at the boundary (the 300C contour line on Figure 3). The total energy stored in the shallow hot water aquifer within the modeled area is estimated to be 1 x 1015 Joules M. The total stored energy, E, was calculated using the following equation: E =AbCp T where: A = area, 0.2 x 106 m2, b = assumed reservoir thickness, 25 meters Cp = heat capacity of reservoir rock, 2.8 x 106 J/m3 _ oC; (based on an assumed porosity of 0 30 an3d a heat capacity for the clay, silt and sand minerals of 2.13 x 10 J/m _ oC; T = temperature differences, 800C. 48 Woodward -Clyde Consultan. Thus, E = total energy in system (referenced to O°C) = 1 x 1015 1. 7.4 SYSTEM HEAT AND WATER BALANCE A schematic heat and water balance for the modeled part of the geothermal system is shown on Figure 26. The heat and mass fluxes presented on Figure 26 were estimated, for the most part, in the manner specified in the previous section. The unknown in the system, the heat and water flux into the system from the assumed fracture system and the heat and water flux out of the system, were derived by solving the energy balance equation. The basic energy balance equation states that the total heat flux into the system must equal the total heat flux out of the system. For the modeled part of the Pilgrim Springs geothermal system, this can be expressed as: Ji=Ja+Jd+Js+Jgw {1) where: Ji = heat flux into the system (MW), Ja = atmospheric heat flux, 6 MW; Jd =downward heat flux, I MW; is = heat flux from springs, 2 MW; i 9 = convective heat flux in ground water out of the system. All of the heat fluxes are referenced to OoC. Ji and Jgw are solved for two assumed cases, one where the aquifer temperature at the system boundary is assumed to be -600C, and the other where the temperature at the system boundary is assumed to be 700C. Also, the temperature of water influx to the system is assumed to be 1000C. The calculation used to estimate Ji and Jgw for the first case is listed below. 49 Wbodwa d.Oyde Consuftan#s Step 1. Express the heat influx, Ji, in terms of ground water flow and temperature into the system. Ji=QixTixK (2) where: r:- Qi = ground -water inflow, cfs; Ti = ground -water temperature, 1000C; K = conversion factor, 0.12 106 x Joules/ft3. (Note: 106 Joules/sec = 1 MW) _ Step 2. Jgu, in terms of ground -water flow and temperature out of the system: Jgw = Qgw x Tgw x K (3) where: Qgw = ground -water flow out of the system, cubic feet per second; Tgw = temperature of ground water, 600C. Step 3. Express Qgw in terms of a water balance for the system: Qgw = Qi - Qs - Qa (4) where: Qs = spring discharge, 0.15 cfs; Qa = evapotransporation loses from modeled area, 0.05 cfs, assuming an E 1 ft/yr/ft ). -T rate of Step 4, Combine equations (1), (2), (3), and (4) to obtain: Qix TixK=Ja+Jd+Js+(Qi-Qs-Qa)xTgwxK (5) Step 5. Replace the variables in equation 5 with the known heat and water fluxes and temperatures, and solve for Qi. Thus: Qi = 1.6 cfs Step 6. Replace Qi in equation (4) and solve for Qgv,. Then: Qgw = 1.4 cfs Step 7. Replace Qi in equation (2) and Qgw in equation (3) and solve for 31 and J g From those calcuations: gv'' Ji=19 MW Jgw = 10 MW, as shown In Figure 26. • WOodward-Ctyde Consultants 7.5 RESOURCE BASE WITHIN THE MODELED PART OF THE GEOTHERMAL SYSTEM The accessible resource base for the modeled part of the geothermal system is estimated to be about 24' MW. This estimate Is based upon the fluxes shown on Figure 26 and a flux estimated by assuming that the energy stored in the system is utilized over a 20 -year period. This latter flux is only 1.5 MW. Assuming that 25 percent of the accessible resource base could be utilized (Muffler and others, 1979), the recoverable geothermal resource is only 6 MW (20 x 106 BTU's/hour). This energy could be produced by flowing one well at a rate of 240 gpm with a water temperature of 900C. The beneficial power, which was estimated using the method of Muffler and others (1979) is about 1 MW. 7.6 ACCESSIBLE GEOTHERMAL RESOURCE BASE The accessible geothermal resource base (Muffler and others, 1979, page 20) for the modeled part of the geothermal system is estimated to be about 24 MW. This estimate is based on a thermal influx of 19 to 24 MW (Figure 26) and a stored thermal reserve in the shallow aquifer system of 1 x 1015 Joules (Section 7.3). If used over a 20 -year period, the stored thermal energy represents a continuous supply of only 1.5 MW (1 x 106 Joules/second = 1 MW). It is notable that the stored energy reserve, as significant as it is, represents about 6 percent of the total thermal resource. More than 90 percent of the resource is available on a sustained basis. With this type of system, the recoverable resource base is determined largely by the manner of capturing the resource. If the well field designed to capture the thermal resource is widely scattered, the recoverable base may be only 25 to 50 percent of the accessible resource. If, on other hand, the source of the thermal energy is identified and a well-defined cone of drawdown is maintained at this source, most of the geothermal resource can be recovered. For comparison purposes, a single geothermal well producing 200 gpm of water at 900C would produce about 5 MW of thermal energy (17 x 106 BTU's/hour). 51 WDodward-Clyde Co1'Isu tants 7.7 LIMITATIONS OF THE CONCEPTUAL MODEL The conceptual mode of the Pilgrim Springs geothermal system (Figure 26) was developed to provide a framework for calculating the thermal and water flux in the hottest part of the geothermal system that has been explored. The estimated heat flux into the system, 19 to 24 MW, and the estimated power stored in the system, 1 x 1015 Joules, therefore, are low estimates of the total heat flux In the overall geothermal reservoir system. This estimated heat flux is sufficient, however, to account for all the temperatures observed within the modeled part of the geothermal system and possibly also for the subsurface temperatures in the entire thaw bulb. As noted in the above model computations, the shallow and deep ground -water outflow from the system, with a combined flux of 1.4 to 1.8 cfs of thermal water and 11 to 16 MW of thermal energy, is not taken into account. Some of this may represent ground -water flow northward from the modeled well -field area toward Pilgrim River where warming effects of the river water having been described by Osterkamp and others (1980). At present, there is no basis for estimating the direction or rate of ground -water flow through the model area. If additional studies show that reservoir temperatures on the margins of the modeled area are higher than assumed in Section 7.4, or if high-temperature areas are identified outside the modeled area, then the estimates of total power derived in the above sections may be too low. 52 0 0 Woodward -Clyde Consultants &0 RECOMMENDATIONS FOR FUTURE WORK Many of the characteristics of the shallow 90+oC saline aquifer system that underlies the Pilgrim Springs thawed area have been confirmed. Neither the heat source nor the water source of the circulating geothermal system have been identified. The summer 1982 drilling and testing program did not locate a conduit feeding the shallow thermal aquifer system or a deeper plume of high-temperature water. Two of the 1982 wells tested the most -evident locations for the possible conduit from depth. PS -3 was drilled only a few feet from where the highest shallow soil temperatures (Figure 3) and the highest soil -helium concentrations (Figure 5) were recovered. Also, PS -5 tested the suggested intersection of two implied high -angle ; fault systems. At each of these likely locations, a highly permeable artesian aquifer system of fresh, cool water occurs immediately under the shallow thermal ground- . water system. The existing six wells at Pilgrim Springs, with proper perforating and development,? are probably adequate for exploiting the shallow 900C saline aquifer system for space -heating and selected uses and also provide a warm potable water supply from deeper aquifers. Although the 90+oC temperatures of the shallow aquifer system are not favorable for the generation of electricity, these temperatures probably represent conditions at considerable distance from a hotter source. Geothermal reservoirs with temperatures considerably above 90oC probably exist somewhere at depth, and a geothermal source with temperatures of 1200C or higher could be nearby. Economides and others (1982) conclude that the conduit supplying hot water to the shallow thermal aquifer system is located near the present well field and is fed from a 1500C reservoir at a depth of 4,875 feet. Wescott (1982, oral communications), believes the conduit is located in the thaw area, probably in the vicinity of wells PS - 2 and PS -3. As discussed in Section 4.1, thermal sources other than an upwelling of deep geothermal waters within the thaw zone cannot be ruled out. Forbes (1982, oral communication) suggests that an apparent thawed area about 2 miles northeast of the Pilgrim Springs well field deserves investigation as a possible source of heat. 53 Woodward -Clyde Consultants Further attempts to model the Pilgrim Springs geothermal system or to extrapolate subsurface data beyond the limits of the proven well field is purely speculative until additional data are available. Some of the needed data are: direction and hydraulic gradient of water flowing in the shallow thermal aquifer system, under static and dynamic conditions; depth, stratigraphy and density (from seismic velocity data of deep valley sediments; and depth, geometry and configuration of the crystalline basement under the valley. Based on earlier geologic mapping and remote -sensing data, we are quite confident that the tectonic setting of Pilgrim Springs is that of a graben valley, with a block - faulted basement floor (see Section 4.0). These studies (Dean and others, 1981) suggest that high -angle basement faults also displace the sedimentary valley fill and intersects the surface. The drilling of well PS -5 to a depth of 1,001 feet at the intersection of the surface expression of two of these faults did not locate either a conduit supplying hot water to the shallow reservoir, or hot water at depth. The confirmation and delineation of subsurface faulting in the sedimentary section is critical to the search for possible conduit systems. Although the Pilgrim Spring geothermal system has been visualized as similar to the fault -controlled system of Cerro Prieto, the heat source that generates the Pilgrim Springs system may be volcanic and relatively young. Youthful basaltic volcanism is displayed by the Lost Jim Flow and other Quaternary volcanic eruptive centers near Imuruk Lake at the east end of the valley and by very young basaltic flows and vents north of Teller. Therefore, the possibility that the thermal drive for the Pilgrim Springs system might be a large mass of basaltic magma that has been emplaced in the sedimentary fill or in the basement fault system should be considered. Studies to date suggest that temperatures higher than those confirmed by present drilling probably exist in the Pilgrim Springs geothermal system. But a "shotgun" approach is unlikely to locate these. The following recommended studies should be considered in the quest for hotter and larger geothermal resources at depth. 54 0 Perforation and Testing of the Four 1982 Wells: 0 VVOOCWM %1_C#yCt Cor"PAt tits An early decision should be made by the Alaska Department of Energy and Power Development and by Mary's Igloo Native Corporation regarding the desired future use of waters from the four 1982 wells. As soon as convenient, a two-week field assignment should be scheduled at Pilgrim Springs to perforate and test selected 1982 wells, to determine the hydraulic and thermal flow gradient and direction in the shallow thermal aquifer system and the thermal production capabilities. This field assignment should include: r o The equilibrated temperature profiles of the six geothermal wells should be repeated o For the 1982 wells selected for completion in the high-temperature shallow aquifer, a cement plug should be set at the base of the thermal aquifer, and the well casing perforated with explosive shot perforations in the zone of highest temperature. o Before flowing the newly perforated wells, the pressure head in all wells tapping the high temperature aquifer system should be precisely measured and water -quality samples collected. From these data, the direction and gradient of circulating ground water and heat in the shallow aquifer system should be calculated. o After all static measurements are completed, each of the newly perforated wells should be properly developed, and the standard hydraulic flow tests run to determine well and aquifer -system parameters of the shallow aquifer system at each of the newly perforated well sites. Seismic Profiling Previous seismic profiles were not definitive, as the equipment, geophone arrays, data channels and blasting techniques were not equal to the unexpected thicknesses U11 Woodward -Clyde Consultants encountered in the valley fill. However, deep seismic profiling with better equipment, involving both refractions and reflection techniques, should produce the desired sections and bedrock topography. In this particular case, the survey techniques, including the geophone arrays, will have to meet the unusual conditions created by: (1) an overlying layer of high velocity permafrost, (2) a thick intermediate zone of poorly consolidated Quaternary and Tertiary sediments, and (3) a high velocity crystalline basement that has probable fault block topography. Airborne Magnetometry Previous airborne magnetometer surveys contracted by the State of Alaska have not had the required resolution to detect relatively small basaltic (diabase, gabbro) masses at depth in the valley fill. Fortunately, permafrost is transparent to magnetic soundings. A closely spaced aeromagnetic grid survey, flown at low speeds with a helicopter at incremental elevations, would be capable of detecting a relatively large mass of mafic rocks in the subsurface, if the temperature was below the Curie Point (6000C) of magnetite. Limiting parameters could be modeled, and this should be done before such a survey is attempted. Exploration Geochemistry Although the mercury and helium vapor surveys appear to have provided valuable data on shallow subsurface thermal anomalies and possible fault traces, a conduit system (if located under the shallow reservoir) was not signaled by either technique. At this point, there is some question as to whether further mercury and helium sampling will clarify the problem. Future surveys should be extended into the outlying areas beyond the Pilgrim thaw elipse, in an attempt to detect lateral feeders, if they exist. Airborne radon surveys have not yet been attempted at Pilgrim Springs, and this technique might have some value, if the grid surveys were flown in the winter on a quiet day, when coherent radon concentration patterns might be preserved. Again, 56 • 0 Woodward -Clyde Consultants such a survey might locate additional thermal anomalies or lateral conduit systems, if they exist. Gravity Surveys The gravity map of the Pilgrim Springs area produced by Kienle and Lockhart (Turner and Forbes, 1980) and further refined by Lockhart (Turner and Wescott, 1981), should be carefully examined to see if the data are amenable to additional refinement and whether additional gravity work to establish a greater station density within the grid is warranted.. The gravity map and data should be of particular value in the selection of airborne magnetometer flight lines and in the interpretation of magnetic data, including total field magnetic gradient surveys. Summary Comments The possible detection of young silicic plutons in the subsurface, if present, by magnetic or gravity surveys is unlikely due to the probable similarity in density and magnetic susceptibility of such plutons to a composite section of glacial outwash, alluvial sediments and possible Tertiary sandstones and conglomerates. i A The highest probability for better target definition is offered by the seismic profiling. Ideally, the survey should be conducted in late winter or early spring, before breakup, when access is good and no surface thawed layer above permafrost can attenuate the transfer of energy from shallow shothoies. This type of survey could be conducted with track vehicles and wanigans. The equipment for such a train could no doubt be assembled from sources in the Nome area. To ensure effective coupling, which has been such a problem in previous surveys, a shothoie rig capable of drilling 100 -foot holes in permafrost would be required. This rig should be available in Nome. The seismic instrumentation, including the capability of large geophone arrays and 24 -channel recording capability, will have to be more sophisticated than that used in previous efforts. 57 C7 • Vloodward-Ctyde Consultants Airborne magnetometry seems to be the next best choice, in terms of possible target definition and of identifying mafic intrusives within the valley floor section. Airborne magnetometry has an inherent economic advantage in that trial runs could be made over representative sections, before a more intensive program was initiated. Conversely, the seismic program represents a total commitment and would be relatively expensive. With the exception of production wells drilled for additional water supply or outlying shallow observation wells to monitor flow gradients in the shallow aquifer system, it is difficult to justify additional drilling without better subsurface data and target definition. A deep well drilled to basement without better target would be very expensive and probably give limited benefits. 58 • 0 Woodward -Clyde Consultants 9.0 REFERENCES Bodvarsson, G.S., Benson, S.M., and Witherspoon, P.A. (1982) Theory of the development of geothermal systems charged by vertical faults: Journal of Geophysical Research, v. 87, no. B 11, pp 9317-9328. Bredehoeft, J.D. and Papadopulos, I.S., 1965, Rates of vertical groundwater movement estimated from the earth's thermal profile: Water Resources Research, vol. 1, no. 2, p. 325-328. Bunder, C.M., Hedge, C.E., and Sainsbury, C.L., 1977, Radiometric concentrations and preliminary radiometric ages of rocks of the Kigluaik Mountains, Seward Peninsula, Alaska: U.S.G.S. Open -File Report 77-735, 36 pp. Cooper, H.H., Jr., and Jacob, C.E. (1946) A generalized graphical method for evaluating formation constants and sumarizing well -field history: American Geophysical Union Transactions, v. 27, no. 4, pp 526-534. Dean, K.G., Forbes, R.B., Turner, D.L., Eaton, F.D., and Sullivan, K.D. (1981) ' Application of radar and infrared airborne remote sensing to geothermal ' resource assessment at Pilgrim Springs, Alaska: Final Report submitted to NASA (Grant NAG 9-8) by University of Alaska, Geophysical Institute, 21 p. Economides, M.J., Economides, C.E., Kunza, J.F., and Lofgren, B.E. (1982) A fieldwide reservoir engineering analysis of the Pilgrim Springs, Alaska, geothermal reservoir: Proceedings, 8th Workshop in Geothermal Reservoir Engineering, Stanford University, Stanford, CA. Ferris, J.G., Knowles, D.B., Brown, R.H., and Stellman, R.W. (1962) Theory of aquifer tests: U.S. Geological Survey, Water -Supply Paper 1536-E, pp 69-174. 59 0 i WAS M Clyde Akan Forbes, R.S. (1980) Uranium -thorium concentrations in representative rocks from Alaskan crystalline terranes: University of Alaska, Geophysical Institute, Report prepared for U.S. Department of Energy, Subcontract 78-219-E, 282 p. Forbes, R.B., Gedney, L., and Hook, J. (1975) A geophysical reconnaissance of Pilgrim Springs, Alaska: University of Alaska, Geophysical Institute, Report No. UAG-R-231, 26 p. Forbes, R.B., Gedney, L., Van Wormer, D., and Hook, J. (1975) A geophysical reconnaissance of Pilgrim Springs, Alaska: Geophysical Institute Report UAG- R231. Gosink, J.P., Osterkamp, T.E., and others (1980) A preliminary investigation of the possible existence of a hot water aquifer under the Pilgrim River: Geophysical Institute Report to Alaska Division of Energy and Power Development. Harrison, W., and Hawkins, D. (1980) Water and heat flow measurements and their relationship to power estimates at Pilgrim Springs, Alaska: in Turner, D.L., and Forbes, R.B., eds., Alaska Geophysical Institute report UAG-R-271. Hopkins, D. (1963) Geology of the Imuruk Lake Area, Seward Peninsula, Alaska: U.S. Geological Survey, Bulletin 1141-C, 98 p. Jacob, C.E., and Lohman, S.W. (1952) Nonsteady flow to a well of constant drawdowwn in an extensive aquifer: American Geophysical Union Transactions, v. 33, pp 559-569. Kienle, J., and Lockhart, A. (1980) Gravity survey of the Pilgrim Springs geothermal area, Alaska: in Turner, D.L., and Forbes, R.B., eds., Alaska Geophysical Institute, Report UAG-R-271. 60 Woodward-CEyft Consukwft !Cline, J.T. (1980) Test drilling report -- Procedures and results of two test holes drilled at Pilgrim Springs, Alaska, in October and November, 1979: Unpublished -Report of Alaska, Division of Geological and Geophysical Survey to Alaska Division of Energy and Power Development. Lockhart, A. (1981) Gravity survey of the central Seward Peninsula: in Wescott, E., and Turner, D., eds., Alaska Geophysical Institute, Report UAG-R-284. Muffler, L.P.J., and others (1979) Assessment of geothermal resources of the United States --1978: U.S. Geological Survey, Circular 790, 163 p. Miller, T.P., Barnes, I., and Patton, W.W., Jr. (1975) Geologic setting and chemical characteristics of hot springs in west -central Alaska, J. Res. U.S. Geological Survey, Vol. 3, No. 2, P. 149-162. Moorman, M.A., and others (1983) Geothermal fluid chemistry of wells and springs at Pilgrim Springs, Alaska: Alaska Division of Geophysical and Geophysical Surveys, Report of Investigations (in preparation). Osterkamp, T. and others (1980) A reconnaissance study of the hydrothermal characteristics and accessible power of Pilgrim Springs, Alaska: in Turner, D.L. and Forbes, R.B. eds., Alaska Geophysical Institute, Report UAG-R-271, pp 113- 156. Swanson, and others (1980) Bedrock geology of the Pilgrim Springs geothermal area, Alaska: in Turner, D.L. and Forbes, R.B., Alaska Geophysical Institute, Report UAG-R-271, pp 7-20. Turner, D.L., and Forbes, R.B., eds. (1980) A geological and geophysical study of the geothermal energy potential of Pilgrim Springs, Alaska: Alaska Geophysical Institute, Report UAF-R-271. 61 Woodward -Clyde Consultants Turner, D.L., and Swanson, S. (1981), Continental rifting -A new tectonic model for the central Seward Peninsula, in Geothermal Reconnaissance Survey of the Central Seward Peninsula, Alaska, (E. Wescott and D.L. Turner, Eds.), University of Alaska, Geophysical Institute Report UAG R-284. Waring, G.A. (1917) Mineral springs of Alaska: U.S. Geological Survey Water -Supply Paper 418, 114 p. Wescott, E., and Turner, D.L. (1981) Geothermal reconnaissance survey of the central Seward Peninsula, Alaska: Alaska Geophysical Institute, Report UAG-R- 284. i 62 0 Tables (a) Feet above sea level (b) PS -3 measuring point assumed to be 25.00 feet above sea level. (c) Klein, 1980. TABLE 1 SU MARY OF GEOTHMUQL *ELL COMPLETION IMFORMRTION Well PS -1 PS -2 PS -3 PS -4 PS -55 MI -1 Depth (in feet) 160 150 260 881 1,001 307 Perforated interval (in feet) 60-100 60-105 167-260 187-881 588-1,001 151-307 Location: From PS -2= distance (in feet) 270 --- 230 247 bearing N450 081E -- S.610 431W S.30 28'E 827 S.30 281E 717 S.750 16-W Metric coordinates—south: 200.00 258.03 291.30 333.24 509.72 313.63 --west- 150.00 208.30 270.13 203.74 193.05 419.75 Date of Drilling 11/1979 11/1979 6/25-7/4 7/5-7/23 7/23-7/28 7/15-7/18 1982 1982 1982 1982 Measuring point, top of upper flange: Height 6 -in, valve 6 -in, valve 10 -in. valve 10 -in. valve 10 -in, valve 10 -in. valve above land surface (in feet): Surface Surface 1.0 2.0 2.0 2.0 Elevation of measuring point(a) 24.61 23.46 25.00(b) 25.89 25.99 24.86 Casing depths (in feet) (see Figures 6 to 9) (c) (c) 16 -in. to 20 16 -in. to 19 16 -in, to 11 16 -in. to 20 10 -in. to 58 10 -in. to 86 10 -in. to 43 10 -in, to 3 6 -in. to 168 8 -in, to 187 8 -in. to 178 8 -in. to 151 3 -in, to 260 no casing 6 -in. to 588 6 -in. to 232 to 881 3 -in. to 981 3 -in, to 307 (a) Feet above sea level (b) PS -3 measuring point assumed to be 25.00 feet above sea level. (c) Klein, 1980. 0 0 *Lost logging probe on second run. TABLE 2 SUMARY OF GEOPHYSICAL DATA OBTAINED PF 0H TEST MAS COMPLETED AT PILGRIM SPRINGS, ALASKA Well Total Depth Geophysical Depth Interval Number of No. (feet) Log Type Logged (feet) Logging Rune PS -1 160 None --- --- PS-2 150 None --- --- PS-3 260 Natural Gamma, 0 to 250 1 SP/RES 58.7 to 78 1 Natural Gamma 162.9 to 250 1 SP/RES 168.7 to 250 1 PS -4 881* Natural Gamma 0 to 511 1 PS -5 1001 None --- --- MI-1 307 None --- --- *Lost logging probe on second run. TABXX 3 (a)Samples collected and analyzed by Alaska Division of Geological and Geophysical. Surveys, (b)WCC measurement, see page 31. IOYPSR QIIALS'y OF WDLS AND SPRINGS (a) (All Chemical Analyses in mg/1) I PS -1 PS -2 PS -3 Pf_ Lake MI -Spring MI -1 S'02 94 92 60 35 4 91 21 CA 511 516 260 23 561 542 5.0 f Mg 0.9 0.9 0.4 0.0 1.0 1.0 0.02 Na 1724 1508 592 115 1658 1658 .16 R 60 57 25 4.8 68 59 0.5 HCO3 30 26 36 BO 27 36 37 SO4 19 19 15 11 10.4 15 9.0 Cl 3420 3420 1430 284 3730 3360 4.7 F 4.4 4.5 1.3 0.5 4.6 4.25 0.19 H2S 4.4 3.4 3.4 ND ND 2.2 ND Sr 13 13 6.0 0.4 14 12 0.0 PH, field 7.52 7.26 7.98 9.75 8.09 6.80 9.67 Dissolved solids 5867 5650 2411 513 6071 5767 76 Sp conductance 9550 9520 4500 270(b) 10300 9440 92 T, OC 92 96 75 48 24 55 24 Date sampled 7-10-82 7-9-82 7-11-82 7-22-82 7-11-82 7-12-82 7-22-82 (a)Samples collected and analyzed by Alaska Division of Geological and Geophysical. Surveys, (b)WCC measurement, see page 31. 1 Derived from drawdown versus time analysis. 2 Derived from specific capacity (Q/s) analysis. 3 None of wells were adequately developed before tests were run. Transmissivity values are considered to be law estimates. TABLE 4 SUNKRIM OF INTIMATES OF TRAMS�QSSIVirr AND BypRAULIC CONDU=Vrrr POR MOLLS AT PILGRIM SPRINGS, ALASKA Probable Producing Zone Well (Feet Below Transmissivity Conductivity No. Landsurface) (gpd/ft) Remarks T(gpd/ft2) PS -1 60 to 80 3,6001 180 (Economides, and others 1982) PS -2 60 to 90 12,6001 420 Fair estimate 12,5002 420 PS -3 167 to 210 4,8001 112 Fair estimate 3,5002 80 PS -4 187 to 360(?) 41,0001 237(?) 8,000 gpd/ft probably 8,0002 46(?) more reliable PS -5 588 to 981 3202 0.8 Sparse data, poor estimate MI -1 151 to 307 2,5001 16 Good estimate 9,0002 58 1 Derived from drawdown versus time analysis. 2 Derived from specific capacity (Q/s) analysis. 3 None of wells were adequately developed before tests were run. Transmissivity values are considered to be law estimates. • rolw No. Pimm Sprinps LOCATION OF PILGRIM SPRINGS 167A GEOTHERMAL WELLS AND ACCESS IFigure Waadwt�ri d•Clyde�� TRAIL FROM TAYLOR HIGHWAY lap .00 1 .l MGL �S �•—ti--• Il! :� � J/' M of tl: , ---�..-.,. � - J f% !M ` � •ter' � rJ - •�V'�_�;-aw i-77 Ln - L�kL oz i J�l 1. • _ : -�.�- ... :, Ti 31 +� ' NY i � � EE �I; `� �� • � � �y _ ff ��+1 f Z� .�•',t •� �,'�f-�; �� ���i....7� a- •'dao �r t � .�•. rolw No. Pimm Sprinps LOCATION OF PILGRIM SPRINGS 167A GEOTHERMAL WELLS AND ACCESS IFigure Waadwt�ri d•Clyde�� TRAIL FROM TAYLOR HIGHWAY 0 0 1982 June July August September 1, Air shipment of drill rig and equipment from Anchorage H 2. Delivery of pipe and drilling supplies in Nome 1..� 3. Mobilization of equipment and supplies to Pilgrim Springs 4. Helium -sampling and preliminary surveys l.y 5. Drilling schedule of wells: PS -3 PS -4 I_ I H PS -5 H MI -1 I„I 6. Hydraulic and hydrothermal testing H 7. Demobilization Project No. pilgrim Springs 15267A SCHEDULE OF 1982 FIELD ACTIVITIES Figure —Woodward -Clyde Consuftants 2 100 W Ids 100 200 300 Q In N Duan+ 4uvw 3UUw zuuw 1uUW 1Wt V v M C Q --1 ;c Origin at 60 C N� Church O �d N > > 40 ca CL cl z 1 y :+ + / 30 PS -1 QO OPS -2 PS -3 1 >p 0 O.MI-1 +so PS -4 3 M p 40 c / 70 60 1 50 / y0 A0 \ 30 sa — PS -5 \ E S 0 500 feet EXPLANATION ._...-30 1979 Temperature contour (°C) at 4.5 -meter depth �• —� Radar lineament Property boundary 0 B.L.M. survey corner p Geothermal well and number Modified after Osterkamp and Others, 1980 Project No. Pil rim Sprin LOCATION OF GEOTHERMAL WELLS 15267A g AND 1979 TEMPERATURE CONTOURS Figure Woodward -Clyde Conautta� TO 100–METER GRID 3 as 9'1 0 s 40OW 30OW 20OW 100W 100S N T4S, R31 W, Sec. 36 T5S, R31W, Sec. 3 200S �— + + PS -1 300SI MI -1 k 400S r- 0 2551 11l - 3() IPS4 5 b PS -5 0 200 400 feet Project No. Pilgrim Springs 15267A g SURVEYED LOCATION OF SIX GEOTHERMAL Figure 1ftodward-CaydeConsultants WELLS WITH RESPECT TO WELL PS -2 4 EXPLANATION O Geothermal well and number B.L.M. survey corner —� 100 -meter grid coordinate IPS4 5 b PS -5 0 200 400 feet Project No. Pilgrim Springs 15267A g SURVEYED LOCATION OF SIX GEOTHERMAL Figure 1ftodward-CaydeConsultants WELLS WITH RESPECT TO WELL PS -2 4 • 0 N 600W 40OW 30OW 20OW 100W 100E IODN M 5.29 eCo n _J t Origin at afl C Church 0 a� W p E d m YL5.31 A0) a M z / M c � .� � 1.47 5.34 t00S � 30 •.. � 5.31 5:8 2005 5.20 5.22 .47 31.72 6.09 52779 (5.26 • • 5.23 5.44 5.28 5.2 6.12 6.10 6.09 13.24 21.84/ 5.26 5.29 40 • • • • • • • • 626 5.• 1 9.67 5.36 6.91 7.07 8.63 113.76 08.87 5.07 5.23 5.27 30DS - ■ • 30 80 12.78 3.49 6.21 7.74 5.3 6.08 6.77 21.28 5.33 5.35 40 • w 70-- • • • / • • w 5.44 i J � 7.87 4005 588 1 .91 5. 60, 6.84 _� 5.27 5.29 ' 5.31 5.27 589 50 .Y7 �..r�.7 7 7.40 6.0 1 11.14 14.50 5.61 13.75 5.63 \6A4 6005 t°h' 6.88 5.54 15.83 5.13) �+j�11.63 7. 1 5.336 5.84 30 so 5.52 5.47 5.28 5.26 5.2 00, 5.21 600S S 0 500 feet EXPLANATION t_ + _-30 1979 Temperature contour (°C) at 4.5 -meter depth Radar lineament ... Property boundary oQ B.L.M. survey comer 5.w25 1982 Helium sample site and concentration (in ppm) 6.21 1979 Helium sample site and concentration (in ppm) III Modified after Osterkamp and others, 1980 Project No. Pilgrim Springs CORRELATION OF SOIL -HELIUM Fi ure 15267A CONCENTRATIONS WITH 1979 SHALLOW 9 5 tylnr.(gydeCongus TEMPERATURE CONTOURS 2 -inch side ports with 2 -inch valves —. G.L. — 17ftft Cement — 58 ft —167.5 ft _ T.O. drilled 260 ft .:*— 10 -inch blind flange -c*--10-inch master gate valve ba AI�.v • D , O� '0 •-� I r i, ,^ 16 -inch casing in 20 -inch auger hole 10 -inch casing in 14-% inch hole -::*-- 6 -inch casing in 9-7/Kinch hole 3- X 5 -inch concentric reducer welded on 3 -inch pipe overlap 12 ft .c--3-inch slotted casing Total length 105 ft Prolect No. Pilgrim Springs 15267A ECASING PROFILE OF WELL PS -3 Figure Woodwar&Clyde Consultants 0 104nch master valve_,.,., 2 -inch outlets with valves G.L. e.. a.. 19ft 86.5 ft Cement 187.4 ft 5 ft drill pipe, 3 drill collars, 7-718 in, stabilizer, sub float & bit for total length of 70.2 ft of steel left in hole TD drilled 881 ft 10 -inch blind flange with 1 -inch nipple for flow —.=:}— 19 ft: 16 -inch casing in 20 -inch hole 86.52 ft: 104nch casing V• �O in 14-3: inch hole �I •e ,e 187.42 ft:8-inch casing a in 9-718 inch hole a Open hole 97/8 inch to 520 ft; 7-7/8 inch below Lost drill stem in open hole Project No. Pilgrim Springs CASING PROFILE OF WELL PS -4 15267A Fi ure Woodward -Clyde COBSuItw is 10 -inch blind flange =--L�- 10 -inch master gate valve--{� G.L. 11 ft 42 ft Cement 178 ft 588 ft 981 ft T.D. drilled 1001 ft 2 -inch side ports with 2 -inch valves - 2 each 16 -inch casing in 20 -inch auger hole VC q 10 -inch casing in 6e 14-% inch hole ea G oG 0 b .a V, 8 -inch casing in Go: 14-% inch hole O Oo� PGde Q .e �' •; Overlap 10 ft e ba 6- X 7 -inch concentric reducer ---- 6 -inch casing in 7-7ii; inch hole 20 ft cement at bottom of 6 -inch casing. 3- X 5 -inch concentric reducer '::1 —" 441 ft: 3 -inch slotted casing Project No. 15267A Pilgrim Springs Figure CASING PROFILE OF WELL PS -5 Woodward -Clyde Comwft ft 8 • 10 -inch blind flange 10 -inch master gate valve G. L. 20 ft 80 ft Cement 151 ft 232 ft T.D. 307 ft 0 •-- 2 -inch side ports with 2 -inch valves ° 20 ft. 16 -inch in ;'4. ' t'o• 20 -inch hole X16 6,0 fOs/'. gerr �� O �' a r•re • r' ff cee_ •y ;r r —<O-- 8 -inch in 14'Y inch hole 6 -inch in 14-% inch hole - i .c*— 3 -inch slotted casing 84 ft l� II Project No. 15267A Pilgrim Springs CASING PROFILE OF'WELL MI -1 Figure Wbodward•CWe Cortlsu9 0 1 c R1M ix�z$"r.• ' Pilgrim Springs r Church PS2 ®b 0 "Spa Mit PS3® e 4 „�Q 4 PS4 PSS strA mf� EXPLANATION (5),0' Weir location; data in a Appendix D Q) Well location Lake Scale • I !/ 1 Project No. Pil rim Springs t5267A g RELATIONSHIP OF PILGRIM SPRINGS Figure 1Nbodwarrd-GyftConsuman" WELL FIELD TO SURFACE STREAMS 10 W • CLAYEY SILT and; 1•14=i SAND (cont'd.) SAND and some SILT GRAVEL and SAND SAND, SILTY SANDSTONE, SAND and CLAYEY SILT and SANDY SILTSONE a= o[scnnnoN waa, SAND, CLAY, and SILT -_ 'i.ta •i SILT and SAND SILTY SAND SILTY GRAVELLY SAND • i.'i ; L •'j :SAND too SANDSTONE t 4 f, iii• -' '00-7SANDSTONE and GRAVEL T.D. 881 ft GRAVEL ^ SAND SANDSTONE. GRAVEL, and CLAYEY SILT SANs• SAND SANDSTONE 30 GRAVEL ; SANDSTONE and AYEY SILTSTONEYEY SILT and SAND ff • CLAYEY SILT and; 1•14=i SAND (cont'd.) SAND and some SILT GRAVEL and SAND SAND, SILTY SANDSTONE, SAND and CLAYEY SILT and SANDY SILTSONE SAND, CLAY, and CLAYEY SILT -_ 'i.ta •i SILT and SAND SAND, SILT, and CLAYEY SILT 'r t 4 iii• SANDSTONE and SAND T.D. 881 ft Project No. Pilgrim Springs 15267A GENERALIZED GEOLOGIC LOG Figure Woocfwwd-CtydeConstftanls OF WELL PS --4 11 0 5 15 20L 0 • • 20 40 60 BO 100 Temperature, in `C EXPLANATION x PS -5 o MI -1 a PS -4 ❑ PS -3 • Mean daily air lest.) Project No. pilgrim Springs INITIAL SHALLOW TEMPERATURE FI ure 15267A 9 V&od mrd -ChrdeConstdtants GRADIENT AT FOUR WELL SITES 12 U U • 0 L i i 1979 Soil Temperature I 1 20- 30- 40- 50- 60- 70- 90.81C 030 40 50607090.8°C at 75 feet --+ an 50 60 70 80 90 100 110 Temperature, in °C EXPLANATION Well shut-in --- -- — Well flowing Project No. Pilgrim Springs 15267A TEMPERATURE PROFILES OF WELL PS --1 Figure VMoodvrard-Cl PftConsuitalnts SEPTEMBER 25, 1982 13 G L 10 1979 Soil Temperature' X ` 20- 30- 40- 50— so- 70— BO 0 30 4050s070BO ' 90.4°C at 87 feet — 4 90 i emperature, in V EXPLANATION Well shut-in — — — Well flowing Project No. Pilgrim Springs g TEMPERATURE PROFILES OF WELL PS -2 Figure 152&7A Woo WWVIa ClydeConsuitants SEPTEMBER 26, 1982 14 Nut W 100 c d v L N 200 3 0 z CL CL 300 400 L- 20 20 , i i i I --49.10C at 245 feet EXPLANATION Well shut-in ------- Well flowing X Soil temperature ou `+u 0u 60 70 80 90 Temperature, in 0C Project No. Pilgrim Springs 15267A TEMPERATURE PROFILES OF WELL PS -3 Figure M NXIwa d�0yide Conacdtants SEPTEMBER 25, 1982 15 0 100 200 m 300 c d w i c 400 3 0 m L CL 0 500 600 700 800 • X—July 1982 1 Data below 500 feet questioned. Probe apparently hanging up. EXPLANATION Well shut—in -- Well flowing X Soil temperature 30 40 50 60 70 80 90 Temperature, in OC Project No. 15267A I Pilgrim Springs TEMPERATURE PROFILES OF WELL PS -4 Figure Mk�odward-Clyde Consuftw is SEPTEMBER 27, 1982 16 10 20 5=6 6 700 800 900 aoo 00 0 X—July 1982 0 f 0 \\ I j i I i 1 I I i 0o CL I t \ EXPLANATION Well shut-in --- Well flowing X Soil temperature \ /48.1 OC at 894 feet ru 30 40 50 60 70 80 Temperature, in OC Project No. 15267A Pilgrim Springs TEMPERATURE PROFILES OF WELL PS -5 Figure V*xK +Ivard►Ctyde Consuitants SEPTEMBER 26, 1982 17 51 W 100 c ti w N c 200 _0 d r p 300 L 420 200C at 285 feet. 30 40 50 60 Temperature, in 0C X X EXPLANATION Well shut-in —•—• Well flowing X Soil temperature 70 80 90 Project No. 15267A Pilgrim Springs TEMPERATURE PROFILES OF WELL MI -1 Figure Nbodward-Clyde Consultants SEPTEMBER 25, 1982 18 ti] 100 200 300 d c d 400 c 0 500 L Y Q ,,rdry 1..1 _ •_� 7 T 1 f I/II//IIII//� Thermal Aquifer System r r �,•~ 1 t 1 600 700- 00 800 800- goo, 90 20 30 40 EXPLANATION -- -- PS -1 ...... I....... PS -2 • - PS -3 ----- PS -4 PS -5 ----- MI -1 50 60 70 80 80 Temperature, in oC Project No. pilgrim Springs 15267A TEMPERATURE VERSUS DEPTH PROFILES Figure Wood lard GlymleConstdtants OF SIX GEOTHERMAL WELLS 19 d d N Q� „g7 f6 Y d 61 C f0 d L U a`+ 97 E 0 N d CL 0 O C O to to m iR • 0 Depth of perforated interval, in feet Ki Project No. Pilgrim Springs RELATIONSHIP BETWEEN INCREASED 15267A ARTESIAN HEAD AND INCREASING Figure Wbodwand�gyde DEPTH, SEPTEMBER 22, 1982 20 6.0 5.0 4.0 m L`D 3.0 d 2.0 1.0 0L 1 • 0 —Pre-test level = 4.92 feet Declining discharge rate • As = 0.75 feet - -`��` .`` • • % 10 100 1uuu Time, T, in minutes T = 2645 U= 36 gpm As As = 0.75 feet = 12,600 gpd/ft K= T b = 30feet IT = 420 gpd/ft2 0 4.0 Lij 5.0 10000 Test data of July 1-3, 1982 Project No. 15ect N Pilgrim Springs SEMI -LOGARITHMIC PLOT OF HEAD VS. TIME Figure lA xX ward-tlyde(%AM tants FOR PS -2 DURING FLOW TEST OF PS -2 21 12 -i--t-�-T 11 10- 9 • c • d • x g 7 6 5 1 0 Pre-test level = 10.79 feet As = 0.32 feet V� 10 100 Time, T, in minutes T = 2645 Q = 50 gpm. As As = 0.32 feet = 41,000 gpd/ft K = T b = 694 feet b = 60 gpd/ft2 0 4.0 5.0 1000 Project No. 15267A Pilgrim Springs SEMI -LOGARITHMIC PLOT OF HEAD VS. TIME Figure VAxX1wsrd•CAydeConsultants FOR PS -4 DURING FLOW TEST OF PS -4 22 10 X g 7 6 E 0 0 Pre-test level = 10.31 feet As = 2.20 feet 0.1 1 10 Time, T, in minutes T = 2640 = 21 qpm As As = 2.20feet = 2500 gpolft K = T b = 156 Leet b _ gp lft2 D 1.0 V O 3.0 4.0 1 5.0 100 Project No. 15267N Pilgrim Springs SEMI -LOGARITHMIC PLOT OF HEAD VS. TIME Figure FOR MI -1 DURING FLOW TEST OF MI -1 23 Woodward -Clyde Consukanfs 12 11 8 7 6 0 0 Pre-test level = 12.45feet As = 2.84 feet 1 10 100 Time, T, in minutes T = 2640 Q = 21 gpm As As = 2.84 feet = 2000 gpolft K = T b = 93feet b = 2.0 gpd/ft2 0 1.0 2.0 4.0 5.0 Project No. 15267A Pilgrim Springs SEMI -LOGARITHMIC PLOT OF HEAD VS. TIME Figure VAXXhvard-ClydeCofaultalnts FOR PS -3 DURING FLOW TEST OF PS -3 24 CD do 0 0 70 60 50 dQ=24.8gpm� 40 � 30- 20- 10— n1 02010n 1 10 100 Time, T, in minutes T = 264 AQ s = 20.3 feet s AQ=24.8gpm = 320 gpd/ft K = T = 320/393 = 0.82 gpd/ft 2 b 1000 Project No. 15267A Pilgrim Springs SEMI -LOGARITHMIC PLOT OF DISCHARGE VS. Figure %ood "rd -Clyde Consault nts TIME FOR PS -5 DURING FLOW TEST OF PS -5 25 0 Ga - 0.05 cfs Ja=6MW Thawed Area Shallow Aquifer System Itl 3 N E m r Q Q3 V y M- eUo O LL N f0 d f Ja = 1 MW Springs Qs=0.15 cfs Js=2 mw Ground Surface Ground -water outflow Qgw, 1.4-1.8 cfs Jaw 10-15 MW Ground -water outflow (?) J 0,1 MW LEGEND Q = ground -water flow rate J = heat flow rate (referred to 0°C) Project No. Pilgrim Springs Figure 15267AL CONCEPTUAL MODEL OF HOTTEST AREA OF 26 %irbrtdwa Idgy�ds�su tardy PILGRIM SPRINGS GEOTHERMAL SYSTEM Appendix D Pilgrim Hot Springs Well Head Repairs Pilgrim Hot Springs Geothermal Exploration Project Pilgrim Hot Springs Wpllhp;;d Rpnair Prepared by: Dan Brotherton, Arctic Drilling, Inc. & Markus Mager, ACEP Fairbanks Alaska, September 2010 AC P Alaska Center for Energy and Power Alaska Center for Energy and Power University of Alaska PO Box 755910 Fairbanks, AK 99775-5910 Pilgrim Hot Springs Wellhead Repair Prepared by: Dan Brotherton, Arctic Drilling, Inc. & Markus Mager, ACEP Overview This task was completed in two phases, including: 1) an initial site visit in July 2010 to assess the condition of the six existing wells and develop a work plan for replacing the wellhead assemblies as needed, and 2) a second trip to the site to complete the work outlined in the work plan. This trip took place September 13th -18th. The goal was to stop the wells from leaking, and make them accessible for instrumentation as part of the DOE funded project 'Innovative Geothermal Exploration of Pilgrim Hot Springs, Alaska'. This report details the work performed on the individual wellheads during the September trip, which included replacing the gate valves on 4 of the 6 wells, including PS -1, PS -3, PS -4 and MI -1. At this time, none of the wells are leaking to the surface although there are still weak points which need to be addressed in the future. Recommendations for future work are outlined in this report. The team performing the work included Dan Brotherton from Arctic Drilling, Richard Eggert, and Max lyapana from Bering Straits Development Company (BSDC), and Markus Mager from ACEP. For each of the four wellheads that were repaired, the team removed the existing gate valves by pumping down the water level in order to access the well and installing new, stainless steel valves. A detailed work description for each well can be found on the following pages. The team did not alter the configuration of the wellheads except for installing an additional fitting on top of the blind flanges capping the gate valves that can accept a 3" stainless standpipe with a tee and a valve to allow future installation of monitoring and logging equipment. A 1" access port with a plug was also built into the top of the blind flange. We recommend installing chains and locks on all the new valves and that all valves should be tested for functionality (opened/closed) at least once a year. Winterization of all the wells is necessary in order to prevent freezing and cracking of the gate valves. A plan for winterization has been forwarded in a separate communication that is attached to this report. Mobilization All new valves (6), parts, tools and supplies, totaling 3,842lbs, were purchased or rented by ACEP and shipped to Nome via Northern Air Cargo (NAC). Additional heavy equipment such as 4 wheelers, trailers, a bobcat and an air compressor were rented in Nome from BSDC. All parts, tools and equipment were transported to the side on September 13th and 14th and staged at the central staging area (Figure 1). Repair work began on the 15th, and tH was completed on the 18 central staging area for repair work Figure 1. Central staging area for repairs. PS-4 (Completed September 14-15`') hottub 9W. PS -4 supplies the water for the hot tub from a tin lower valve. The well was leaking from a % inch hole in the blind flange on top of the 10in well gate valve and from the corroded 2in valves on each side of the 10in casing underneath the 10in valve (Figure 2). The lower bolt flange of the 10in valve was covered with mineral buildup and corrosion scale. There was a small pond around the well at the level of the 2in side valves from the constant leaking and overflow from the tub. The team laid down timbers and planks to create a stable work platform and removed mineral build up and rust scale from the lower bolt flange (Figure 3). After various failed attempts to release the old 10in valve from the well flange, the bolts had to be cut off with a torch (Figure 4 & 5). 3 PS -4 mineral buildup and corrosion scale �_ 11Y I 111 IMW 1' i leaks Figure 2. Arrows show areas of leaking on PS -4. IN601 Removing mineral buildup and corrosion scale from lower flange Figure 3. Removing buildup and scale and attempting unsuccessfully to cut the flange bolts with a Sawzall. 4 [1•"1 El! Figure 4. Cutting bolts to remove old gate valve. ® s k _ ,PS7 Figure 5. Removing gate valve with Bobcat — note artesian flow from well. PS -4 has an inner Bin and an outer 10in casing. The outer casing is corroded and thin. The 8in/10in annulus (space between the two casings) continued to produce water after the water level inside the Bin casing was drawn down. This indicates a likelihood that they are set to different depths and water is produced from a different production zone in the annular space than through the main hole. In order to weld on new tin nipples, this water would need to be drawn down. We were able to partly draw this water down with a lin suction tube, but it was ultimately decided to not risk changing the tin nipples after it was determined they are corroded but still sound (probably just as sound as the casing). Dan was not confident that the casing could be welded given its state of deterioration, so rather than risk creating a difficult to stop leak, the original nipples were left in place and only the tin valves were replaced with new stainless 2" valves (Figure 6). PS -4 new valves New 2in valves but nipples they attach to were not replaced N, l� �s Corroded old casing and the two nipplesare still weaknesses Figure 6. New valves. The flange on this well is partly eaten away but still appears to be sound. The well is artesian and produces clear water. We installed a new 10in stainless steel valve with reducer flange on top connected to a 3in threaded nipple with a stainless cap. The well has no visible leaks and has been re -connected to the hot tub via one of the new 2in valves. Further repairs on this wellhead will be needed in the near future. The 10in casing and the 2in nipples are thin and will eventually start leaking with no way to control or stop the flow. Dan recommends that the 8-10in annulus be cemented from the bottom up to the top via tremie pipe which would seal off the corroded outer casing from the well water and would extend the life of the well. We are also recommending locks on the 2in valves to guarantee flow to the hot tub, prevent accidently closure (or opening) and to prevent well freeze up since this well will presumably not be shut in through the winter. If this is the case, it is imperative that the 2in valve remains open to prevent the new gate valve from freezing. 1i PS -3 (Completed September 15 -16th) Prior to repairs, this well was leaking through the standpipe at the top of the well and later, after we started to remove buildup and scale (Figure 8), from a hole in the side of the 10in valve (Figure 7). We were unable to plug this leak so we dug a sump hole to drain the fluid and temporarily pump it away from the well and surrounding work space. PS -3 example of corroded standpipe crating off PS -3 Figure 7. Image showing leaks and corroded standpipe. of wellhead 7 PS -3 remove scale & mineral buildup from old vra lve Figure 8. Removing scale and buildup. There was significant corrosion to several of the bolts connecting the existing gate valve to the wellhead flange, which necessitated cutting them off with a torch. We were able to drive out some of the bolts once they were cut, but several posed additional challenges and had to be removed in chunks. The torch was damaged during this process. Eventually we were able to remove the old 10in valve and replace it with the new stainless valve and bolts. The lower flange of the wellhead is severely corroded and the new flange bolts are exposed. The flange thickness is about half of original thickness and there is barely enough material left to secure new flange bolts (Figure 9). The well was completed with a new capped gate valve and blind flange, with a 3in nipple and cap. There is a tin valve below the flange which was left in place as it is not currently leaking. Dan was not confident the well casing is sound enough to permit replacement of this valve. PS -3 exposed bolts and old 2 inch valve exposed bolts old flange in bad condition I' oLA old 2inch valve not replaced 4170. >, PS -3 Figure 9. Exposed bolts, new valves. PS -3 is hotter than PS -4 and produces clear water. There is also a 6in inner casing in this well that comes to the top of the 10in casing. Once the old valve was replaced, there were no visible leaks. Figure 10 shows a comparison of the old PS -4 valve flange and the old PS -3 valve flange. PS -3 & PS- -�.. old Valves a. F Figure 10. Old loin valves from PS -3 and PS -4. Note severe corrosion on lower PS -3 flange. Further repairs will be needed to this wellhead soon. Dan recommends cementing the 6-10" annulus from the bottom up with tremie pipe so that the side valve can be removed and the main well flange can be replaced. This will protect the well from a permanent leak if one develops from the corroded casing. MI -1 (Completed September 16 -18th) This well is located on adjacent Mary's Igloo Native Corporation land. The top of the 10in gate valve was split in half, probably due to a freeze break. We were able to open and close the old gate valve but could not completely stop the flow of the well. MI -1 is colder than PS -4, and the water temperature of this artesian well appears to fluctuate. When flowed for a short period of time it produced gray, silty fluids. The well has no visible inner well casing. Due to leaks in the wellhead, a small pond had formed around the well several inches deep. We cleaned out an existing trench leading away from the well and the pond drained away to ground level. We built a work platform around the well and removed mineral build up, rust and scale from the bolts. Dan cut the bolts and drove them out with the torch. We removed and replaced the 10in valve with new stainless steel valve and bolts (Figure 11). The new gate valve is capped with a blind flange with 3in welded nipple and cap. 9 IMAM MI -1 new valve Figure 11. Work commences on MI -1. Note artesian flow prior to pumping. Prior to repairs, the well was also leaking from several holes corroded through the casing below the gate valve flange. These leaks continued after installing, capping and shutting the new gate valve. The casing is paper thin midway between the flange and the cement. Dan welded a sleeve around the casing from about 2in above the cement level up to the flange, totaling about 14in. In order to weld on the sleeve, he completely removed the side valve, nipple and weldolet from the 10in casing. The sleeve stopped the leaks temporarily but the casing below the sleeve is thin and remains a significant weakness (Figure 12). Dan recommends installing a 6in inner casing and cementing the annulus from the bottom to the top via tremie in order to prevent further leaking once the casing corrodes further. KAI 1 MI -1 repair work on casing installation of new sleeves Figure 12. Casing conditions of MI -1. 10 PS -1 (Completed September 18t) PS -1 is the hottest of the repaired wells. This well was buried past the valve handle and covered with several inches of mineral buildup. Before repairs, it leaked out of a corroded two inch elbow from the top of the wellhead, as well as the remains of a tin valve and a lin hole in the top of the well cap (Figure 13). These holes were plugged with sticks driven into the openings after some of the mineral build up was removed. We then excavated around the well to just below the lower valve flange covering an 8ft by 10ft area, dug a sump hole for the water pump and laid down blocking and timbers for a work platform. We removed the mineral build up and de -scaled what remained of the bolts (Figure 14). PS-1� �- before repair work starts Figure 13. PS -1 after excavation but before repair work. 11 Max remove scale & mineral buildup from Figure 14. Removing scale and buildup prior to replacing gate valve. When the gate valve was removed, it was evident that the lower flange was almost completed corroded away with no bolt heads remaining and the bolt threads visible from the side of the flange. We used the torch to remove the bolts, removed the old gate valve, cleaned up the flange as much as possible, and installed the new 6in stainless valve topped with a stainless blind flange, 3in nipple and cap (Figure 15). new valve Figure 15. New valve installed on PS -1. Note collapsed suction hose due to high temperatures. This well has a 4in inner casing inside the 6in outer casing, and does not have any lower casing tin valves. There is not much left of the well flange, just barely enough to bolt on the new valve. The well is sealed and does not 12 leak at this time. We backfilled around the well but not to the previous level so it is possible to access valve handle. We left the remaining dirt piled to the side of the excavated area. Dan recommends installing a short (18in) spool section underneath the new gate valve to raise the valve above ground level and permit the well to be backfilled to ground level. This would also eliminate the standing water around the well, which is now below grade. He also recommends cementing the 4in-6in annulus and welding on a new casing flange in order to prevent future leaks. PS -2 This well is buried but inaccessible with rubber tired backhoe. We did not attempt to dig up this well. The wellhead valve is not corroded or leaking. We will attempt to make it accessible for instrumentation in 2011. Figure 16. PS -2 buried but not leaking. We will need to excavate and replace valve before this well can be accessed with instruments. PS -S This well is also not corroded or leaking so we did not replace the valve at this time. We will attempt to make it accessible for instrumentation in 2011. 13 Figure 17. PS -5 still appears to be in good shape, but not accessible by instrumentation. Winterization Plan for Wellheads (Dick Benoit and Gwen Holdmann) The trick to keeping a wellhead from freezing and then breaking during sub freezing weather is to inject a liquid that is both less dense than water and has a very low freezing point into the wellhead. This fluid needs to be environmentally benign so that when (not if) it is spilled or leaks out of the wellhead it does no environmental damage. Typically a food grade vegetable oil has been used in the lower 48. A small pump is used to pump the oil into the highest opening in the wellhead but if the pressures are very low even a hand operated pump may be enough to do the job. We expect this to be the case for the Pilgrim wells. This pump obviously needs to be able to overcome the internal wellhead pressure and can pump at low rates. You will need to know how much oil has been pumped into the wellhead. Enough oil needs to be pumped into the wellhead to push or displace the water down the well to a point below the freezing level, which is probably not more than a few feet. Therefore, it is necessary to calculate the volume of the wellhead above ground and a few feet of wellbore below ground. We expect this might amount of a few tens of gallons per well. It is important to check the wellhead for leaks, no matter how slow, before injecting the vegetable oil. If the oil leaks out of the wellhead then the water will flow back up in the wellhead and freeze. We recommend doing this on the 4 wells with new gate valves prior to hard freeze-up. 14
