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208-207
0 • Image roject Well History File Cover Page XHVZE This page identifies those items that were not scanned during the initial production scanning phase. They are available in the original file, may be scanned during a special rescan activity or are viewable by direct inspection of the file. OQQ 8 - Q2 d 7 Well History File Identifier Organizing (done) ❑ Two -sided III 1E11 I II II III ❑ Rescan Needed 1 1 1111 1111 RESCAN DIGITAL DATA OVERSIZED (Scannable) ❑ Color Items: ❑ Diskettes, No. ❑ Maps: reyscale Items: ❑ Other, No/Type: ❑ Other Items Scannable by a Large Scanner ❑ Poor Quality Originals: OVERSIZED (Non - Scannable) ❑ Other: ❑ Logs of various kinds: NOTES: ❑ Other:: BY: Date: 7/1 41/(P--- /s/ Project Proofing I 11111111111 BY: (Maria Date: 7///o/ p2 is/ Scanning Preparation f x 30 = 30 + /7 = TOTAL PAGES 47 (Count does not inlsl y clude cover sheet) �/1 /i BY: Maria Date: / 1 d — Production Scanning 1 flhlllhIIIIIIII � � I Q' Stage 1 Page Count from Scanned File: �`'i" v (Count does include cover sheet) Page Count Matches Number in Scanning Preparation: VES NO BY: Date: 7/(ff. is/ f Stage 1 If NO in stage 1, page(s) discrepancies were found: _ YES NO BY: Maria Date: /s/ Scanning is complete at this point unless rescanning is required. I I ReScanned 1 I BY: Maria Date: /s/ Comments about this file: Quality Checked III IIIIII IIIIIII f III 12/22/2011 Wet History File Cover Page.doc DATA SUBMITTAL COMPLIANCE REPORT 7/3/2012 Permit to Drill 2082070 Well Name /No. STEGODON 24 -6 -8XX Operator UNION OIL CO OF CALIFORNIA API No. 50- 287 - 20026 -00 -00 MD TVD Completion Date Completion Status Current Status CANC UIC N REQUIRED INFORMATION Mud Log Yes Samples No Directional Survey No DATA INFORMATION Types Electric or Other Logs Run: (data taken from Logs Portion of Master Well Data Maint Well Log Information: Log/ Electr Data Digital Dataset Log Log Run Interval OH / Type MedlFrmt Number Name Scale Media No Start Stop CH Received Comments Well Cores /Samples Information: Sample Interval Set Name Start Stop Sent Received Number Comments Cores and /or Samples are required to be submitted. This record automatically created from Permit to Drill Module on: 1/7/2009. ADDITIONAL INFORMATION Well Cored? Y / N Daily History Received? Y / N Chips Received? Y / N Formation Tops Y / N Analysis Y / N Received? Comments: t \ \© 0. ,ti L � 1. F C f e Compliance Reviewed By: Date: ) N S- ) ' • Page 1 of 1 - 1/13/2010 &u McMains, Stephen E (DOA) .20? - 010 From: Kanyer, Christopher V [Chris.Kanyer @chevron.com] Sent: Wednesday, January 13, 2010 1:10 PM To: McMains, Stephen E (DOA); Aubert, Winton G (DOA) Cc: Brandenburg, Tim C; Bonnett, Nigel (Nigel.Bonnett); Tyler, Steve L Subject: Cancellation of open sundries /permits After reviewing the following open permits to drill (form 10- 401) /sundries (form 10 -403) for Union Oil Company of California, it has been determined these open AOGCC permits /sundries should be cancelled: PTD Sundry API Well Name /Number 209 -011 N/A 50- 233 - 20025 -00 Panthera 21-6 -9 208 -207 N/A 50- 287 - 20026 -00 Stegodon 24-6 -8 209 -058 N/A 50- 733 - 20586 -00 Trading Bay Unit M -08 197 -067 308 -252 50- 733 - 20043 -02 A -08RD2 201 -117 308 -269 50- 733 - 20254 -01 Trading Bay Unit K -18 195 -083 308 -268 50- 733 - 20097 -04 Trading Bay Unit K -26RD 208 -184 309 -198 50- 283 - 20130 -00 Ivan River Unit (IRU) 11 -06 Please let me know if you have any questions. Thanks, Chris Kanyer •• Technical Assistant Wellbore Maintenance Team Office: (907) 263 -7831 Cell: (907) 250 -0374 Chevron North America Exploration and Production Midcontinent/Alaska SBU 3800 Centerpoint Dr, Suite 100 Anchorage, AK 99503 1/13/2010 4 1 ,,,,,,ti, i r I ` A ` ( (` �. / / @ ; L Q j ,�.� L � L.� I. .1.),J /1- "� SARAH PAL1N, GOVERNOR ALASKA OIL AND GAS , I 333 W. 7th AVENUE, SUITE 100 CONSERVATION COMMISSION ANCHORAGE, ALASKA 99501 -3539 PHONE (907) 279 -1433 Tim Brandenburg FAX (907) 276 -7542 Drilling Manager Unocal 3800 Centerpoint Dr., Ste 100 Anchorage, AK 99503 Re: Exploratory, Stegodon 24 -6 -8 Unocal Permit No: 208 -207 Surface Location: 1004' FNL, 1630' FWL, SEC. 24, T6N, R8E, UM Bottomhole Location: 1004' FNL, 1630' FWL, SEC. 24, T6N, R8E, UM Dear Mr. Brandenburg: Enclosed is the approved application for permit to drill the above referenced exploration well. All dry ditch sample sets submitted to the Commission must be in no greater than 30' sample intervals from below the permafrost or from where samples are first caught and 10' sample intervals through target zones. This permit to drill does not exempt you from obtaining additional permits or approvals required by law from other governmental agencies, and does not authorize conducting drilling operations until all other required permits and approvals have been issued. In addition, the Commission reserves the right to withdraw the permit in the event it was erroneously issued. A weekly status report is required from the time the well is spudded until it is suspended or plugged and abandoned. The report should be a generalized synopsis of the week's activities and is exclusively for the Commission's internal use. Operations must be conducted in accordance with AS 31.05 and Title 20, Chapter 25 of the Alaska Administrative Code unless the Commission specifically authorizes a variance. Failure to comply with an applicable provision of AS 31.05, Title 20, Chapter 25 of the Alaska Administrative Code, or a Commission order, or the terms and conditions of this permit may result in the revocation or suspension of the permit. When providing notice for a representative of the Commission to witness any required test, contact the Commission's petroleum field inspector at (907) 659 -3607 (pager). b nce -1 V 6 aniel T('Seamount, Jr. Chair DATED this if day of January, 2009 cc: Department of Fish & Game, Habitat Section w/o encl. Department of Environmental Conservation w/o encl. 1 V ..,...., 1 STATE OF ALASKA ili DEC 23 2008 ALASKA OIL AND GAS CONSERVATION COMMISSION .,t G as cons. Comml$SICS1 PERMIT TO DRILL At ,........ Alaska ���,� 20 MC 25.005 / Aild 1a. Type of Work: 1b. Current Well Class: Exploratory S Development Oil ❑ 1c. Specify If well is proposed for. Drill 0 Redrill ❑ Stratigraphic Test ❑ Service ❑ Development Gas ❑ Coalbed Methane ❑ e as Hydrates ❑ Re -entry ❑ Multiple Zone ❑ Single Zone ❑ Shale Gas ❑ 2. Operator Name: 5. Bond: Blanket Si Single Well ❑ 11. Well li.. me and Number. Union Oil Company of California Bond No. 086S103515406BCM • Stegodon •4-6 -8 3. Address: 6. Proposed Depth: , 12. Field /•ooI(s): 3800 Centerpoint Drive, Suite 100, Anchorage, AK 99503 MD: 5000 • TVD: 5000 Exploratio 4a. Location of Well (Governmental Section): 7. Property Designation: Surface: 1004' FNL, 1630' FWL, Sec 24, T6N, R8E, Umiat Meridian ADL 390931 • Top of Productive Horizon: 8. Land Use Permit: 13. Appro imate Spud Date: 1004' FNL, 1630' FWL, Sec 24, T6N, R8E, Umiat Meridian ADNR LAS 26542 2- Feb-09 Total Depth: 9. Acres in Property: 14. Distan - to Nearest 1004' FNL, 1630' FWL, Sec 24, T6N, R8E, Umiat Meridian 5760 Property: 37,946 / 4b. Location of Well (State Base Plane Coordinates): 10. KB Elevation K$ Say/ A! 15. Distan - to Nearest Well Surface: x- 495,910 • y- 5,800,029 . Zone- ASP4 (Height above GL): 44,, 483 f et /404 Within Po I: None 16. Deviated wells: Kickoff depth: feet 17. Maximum Anticipated Pressures psi (s 20 AAC 25.0 5) Maximum Hole Angle: degrees Downhole: 2165 • Surface: 969 ' 18. Casing Program: Specifications Top - Setting Depth - Bottom Ce ent Quantity, c.f. or sacks Hole Casing Weight Grade Coupling Length MD TVD MD TVD (including stage data) Augered 16 65 N -80 Weld 165 0 0 186 186 As Requir d to Surface 12 -1/4 9 -5/8 40 L -80 BTC 1850 0 0 . 1850 • 1850 Lead: 246 bbls(333 sx) of 10.7 ppg(4.15 sx) PF "L" (250% excess) Tail: 53 b• s (254 sx) of G @ 15.8 ppg (1.16 ft/sx (40% Excess) 8 -1/2 4 -1/2" 12.6 L -80 IBT -M 3300 1700 1700 5000 5000 288 bbls (.79 sx) of G with Econlite @ 11.5 ppg (•.8 ft/sx) (40% excess) 19. PRESENT WELL CONDITION SUMMARY (To be completed for Redrill and Re -Entry Operations) Total Depth MD (ft): Total Depth TVD (ft): Plugs (measured): Effect. Depth MD (ft): Effect. Depth TVD ( ): Junk (measured): Casing Length Size Cement Volume MD TVD Conductor/Structural Surface Intermediate Production Liner Perforation Depth MD (ft): Perforation Depth TVD (ft): 20. Attachments: Filing Fee ❑ BOP Sketch El Drilling Program 61 Time v. Depth Plot 0 Shallow Hazard Analysis0 Property Plat 0 Diverter Sketch 0 Seabed Report ❑ Drilling Fluid Program 0 -0 AAC 25.050 requirements 21. Verbal Approval: Commission Representative: Date 22. I hereby certify that the foregoing is true and correct. Contact Walter Q = y 263 - 7812 Printed Name Tim Brandenburg Title Drilling Manager Signature - J Phone 263 -7657 Date 12- Dec-0; Commission Use Only Permit to Drill • API Number. ,, Permit App ova See cove letter for other Number. z j ^� / 50- '2 ? zpoz6 "'0IDate: I. • ® requirem ts. Conditions of approval : If box is checked, well may not be used to explore for, test, or produce co Ibed methane, gas hydrate-, or gas contained 1 s: Other: Samples req'd: Ye No ❑ Mud log req'd: 4 1 N 4j vv hj ` �..� . � \ 4; - c5�,,,. ovs., 3GYS H measures: Ye ✓ No❑ Direct •nal svy req'd: Ds o ig ) %der \e -- C.+r-k.**'/ k)1' Av :c_CLCx.Ct'7kaVfc i x - ..G1/4s �t - i/Z /� AP•ROVED BY THE COMMISSION !// DATE: I�l COMMISSIONER A /. 7 # Form 10-401 Revised 12/2005 ! h i Submit in Duplicate Chevron • Timothy C Brandenburg Union Oil Company of California %O. Drilling Manager 3800 Centerpoint Dr. Suite 100 Anchorage, AK 99519 -6247 Fax 907 263 7884 December 17, 2008 :DE:Gas2Econi3Vs2.0Ec008mDmission Commissioner Alaska Oil & Gas Conservation Commission 333 W. 7 Avenue Anchorage, Alaska 99501 Alaska Re: Application for Permit to Drill Stegodon 24 -6 -8 Exploration Well Anchorage Dear Commissioner: Enclosed for approval is a Permit to Drill (form 10 -401) for Union Oil Company Of California to drill the Alaska North Slope White Hills Exploration well, Stegodon 24 -6 -8. Subject to AOGCC approval, it is intended to drill Stegodon 24 -6 -8 with an anticipated spud date of February 2, 2009. A variance from requirements of 20 AAC 25.035, to utilize a diverter vent line diameter of 12" is requested. This is smaller than the planned surface hole of 12 -1/4 ". A similar request was approved for Smilodon 9 -3 -9, Mastodon 6- 3-9, Panthera 28 -6 -9 and Muskoxen 36 -7 -8 wells with Nabors 106E rig. The AOGCC is requested to treat as confidential all information included in the Application for Permit to Drill as information in these documents is drawn from research and data proprietary to Union Oil Of California a wholly owned subsidiary of Chevron Corporation. If additional information is required, please contact either myself or Mr. Walter Quay at 263 -7812. Pertinent information attached to this application includes the following: 1. Form 10 -401 Application for Permit to Drill — 2 Copies 2. Well Program 3. Wellbore Schematic 4. Drilling Fluids Program 5. Directional Program 6. As Staked Location Plat 7. Days Vs Depth Drilling Plot 8. MASP Calculation & Casing Design 9. Diverter, BOP and Choke Manifold Schematics 10. Shallow Hazard Analysis Sincerely, Timo . randenburg Drilling Manager Cc: Well File Union Oil Company of California / A Chevron Company http: / /www.chevron.com Chevron OP II Drilling Department Z Stegodon 24 -6 -8 Well Plan Summary Surface Location: X = 495,910' • Y = 5,800,029 • As - Staked • 1004' FNL, 1630' FWL, Sec. 24, T6N, R8E UM Target Location: X = 495,910' Y = 5,800,029 Schrader Bluff A 1004' FNL, 1630' FWL, Sec. 24, T6N, R8E UM Target Location: X = 495,910' Y = 5,800,029 Schrader Bluff B 1004' FNL, 1630' FWL, Sec. 24, T6N, R8E UM Target Location: X = 495,910' Y = 5,800,029 Schrader Bluff C 1004' FNL, 1630' FWL, Sec. 24, T6N, R8E UM Bottom Hole Location: X = 495,910' Y = 5,800,029 1004' FNL, 1630' FWL, Sec. 24, T6N, R8E UM The well approaches within 37946' of the nearest UOCC White Hills lease line. Estimated Start Date: 102/02/2009 1 1 Operating days to complete: 128 I MD: (5000' • 1 TVD: 15000' - I Elev. GL: 1483' • 1 ( RKB: 121' Formation Markers: Formation Tops MD - RKB TVD - RKB TVD-GL Comments Base Permafrost 1338 1338 1317 Top Prince Creek A 1339 1339 1318 Top Schrader Bluff A 2696 2696 2675 Top Schrader Bluff B 3503 3503 3482 Top Schrader Bluff C 4102 4102 4081 Top Coleville • 4249 4249 4228 Est. TD 5000 5000 4979 Casing Program: Hole Csg/ Wt/Ft Grade Conn Length Top Btm Size Tbg O.D. MD/TVD MD/TVD rkb Augered 16" 85# L -80 Welded 165' GL 186' 12 -1/4" 9 -5/8" 40.0# L -80 BTC 1839 GL 1850/1850 8-1/2" 4-1/2" 12.6# L -80 I BT -M 3300' 1700'/1700' 5000'/5000' 12/12/08 2 of 41 • 1 Mud Program: 12 -1/4" Surface Hole (0- 1850'): Fresh Water Mud Initial Value Final Value Density (ppg) 8.5 9.0 -9.4* • Funnel Viscosity 100 -200 70 -150 (seconds) Yield Point 30-40 20 -30 (cP) Plastic Viscostiy (lb/100 10 -30 12 - 25 sf) 10 second Gel Strength 10 -15 10 -15 (lb/100 sf) 10 minute Gel Strength 20-40 20-40 (lb/100 sf) pH 9 -9.5 9 -9.5 API Filtrate(cc) Unrestricted <10 8 -1/2" Production Hole (1850' — 5000'): Fresh Water Mud — 6% KCL/PHPA /Clayseal with Calcium Carbonate Initial Value Final Value Density (ppg) 9.1 9.5 Max • Funnel Viscosity 45 -70 45 -70 (seconds) Yield Point (cP) 15 -25 15 -25 Plastic Viscostiy (lb/100 10 -22 12 -24 sf) 10 second gel 4 -8 4 -8 10 minute gel 6 -13 6 -14 pH 9 -9.5 9 -9.5 API filtrate <3.5 <3.5 Solids % 0 <6 Hydraulics: Surface Hole: 12 -1/4" Interval GPM Mfg Bit Pump PSI ECD ppg- Nozzles TFA emw (in 0' -1850' >600 Hughes MX -L1X 1800 9.7 13/15/15/1E 0.65 Production Hole: 8 -1/2" Interval GPM Mfg Bit Pump PSI ECD ppg- Nozzles TFA (in`) emw 1850' — 5000' 450 Reed DS619S -A3 2400 9.6 6 x 12/32" .66 Hycalog 12/12/08 3 of 41 Logging Program: Logging While Drilling Hole Size Services Run 1 0 -surf csg LWD: GR /Res /Sonic /Directional • Run 2 surf csg -TD LWD: GR /Res /EcoScope /Sonic /Directional • Run 3 Mud Logging_ Services 0 -surf csg Mudlogger required from surface to TD ° Company Geologist required from Surface to TD • 0 -TD Bagged samples of cuttings every 30 feet, with 10 ft samples caught from sandstones and other potential reservoirs from surface to TD (both legs); three washed and dried cuts, one unwashed cut. Check all sandstones with drilloffs for oil fluorescence and cut. Isptube gas sample from mudlogger over all zones of interest. Coring Hole Size Services surf csq - TD I Rotary sidewall cores • Open Hole Logging Services Hole Size Run 1 8 -1/2" GR- SP- CNL -LDT -Res W /Micro Restivity • Run 2 8 -1/2" MREX W /Micro Restivity Run 3 8.1/2" RCOR Run 4 8 -1/2" WL RCI (Pressures & Temperature Measurements) Run 5 8 -1/2" DP Conveyed RCI(MDT Type Formation Sampler & Pressure) Run 6 8 -1/2" VSP (Minimum checkshot) If WLD data is of sufficient quality, then the GR -CNL NOTE LDT restivity will be omitted. Integrity Testing: Test Point Depth Test Type EMW Surface Casing Shoe At least 20 feet but not more than LOT Estimated 12.5 ppg EMW. • 50 feet of new formation Take the test to Leak Off Cement Calculations: Casing Size 1 9 -5/8" Surface Basis: Lead: Based on conductor set at 180', 1137' of annulus in the permafrost @ 250% excess. Tail: Based on 533' open hole volume + 40% excess + 85' shoe track volume. Total Cement Volume: Lead 246 bbl / 1382 ft / 333 sks of Permafrost Type L at 10.7 ppg and 4.15 cf /sk. Tail 53 bbl / 295 ft'/ 254 sks of Premium 'G' at 15 8 ppg and 1.16 cf /sk. Production /Abandonment Liner: Casing Size 14 -1/2" Liner Basis: Float Collar 60' below liner hanger, cemented inside liner from float collar to TD. 40% excess volume in OH from shoe to surface shoe, 150' of liner lap inside surface casing + 100' of excess above the liner top (DP Out) Total Cement Volume: Cement 288 bbls / 1621 ft 579 sks of Premium Cement, 3% Econlite slurry at 11.5 ppg and 2.8 cf /sk 12/12/08 4 of 41 I 1 1 Well Control: Surface hole will be drilled with a diverter. The MASP is 969 psi. (See Attached) The intermediate /production hole well control equipment (of at least 3000 psi working pressure) consisting of will be equipped with pipe ra s, blind rams, and an annular preventer will be installed and is capable of handling the MASP p essure. Based upon the planned casing test of 2000 psi for casing integrity conside =tions, the BOP equipment will be tested to 2500 psi. Disposal: • Cuttings Handling: Cuttings generated from drilling operations hauled to a approved disposal facility. • Fluid Handling: All Mud and Used drilling and completion fluids and oth-r Class 11 wastes hauled to an approved disposal facility. Wastes Handling See the Comprehensive Waste Management plan for all details on Waste Handling Excess/Used Liquid Mud & Excess Cement Returns Used liquid mud will be stored in a heated tank farm on the first drill site for the 2109, then hauled overland to a disposal site in GPB. Cement returns and wash will be citrate treated, then stored in the used mud tank f. rm. This cement should be blended with used mud to dilute the cement concentration. Drill cuttings Drill cuttings will be processed by the rig solids control equipment to remove as m ch liquid from them as possible. The "dry" cuttings will be stored in an ice containment pit in the pad. NO LIQUIDS ARE ALLOWED IN THE CONTAINMENT PIT. The drill cuttings with be stored in the containment pit until: 1) they are backhaul =• to Deadhorse via Cat 730 ejector trucks with tundra tires to an approved disposal are.. 12/12/08 5 of 41 • Summary of Drilling Operations Pre -Rig Work: 1. Set and cement 16" conductor 2. Install cellar Rig Operations: 1. Nipple Up the 13 -5/8" BOP diverter spool and riser in diverter mode. Function test div-rter system. Provide the AOGCC at least 48 hours notice of each BOPE function pressure test so t at a commission representative can witness the test 2. MU 12 -1/4" drilling assembly. Drill surface hole to approximately casing point ( -500' blow the permafrost). Drift the drillpipe to 2.4" min. ID for the stab -in dart. 3. Run and cement the 9 -5/8 ", 40.0# surface casing back to surface. A Stab -in cementing system will be utilized. 4. RU the BOPE in BOP Mode and test to 250/2500 psi. Provide the AOGCC at least 48 ours notice of each BOPE function pressure test so that a commission representative can witness th- test 5. MU 8 -1/2" drilling assembly and RIH to float collar. Test the 9 -5/8" casing to 2000 psi or 30 minutes. 6. Drill out shoe joints and new formation greater than 20' and Tess than 50'. Perform t Leak Off Test. 7. Drill ahead to planned TD 8. Circulate and condition hole and perform wiper trip to surface casing shoe. POOH an. stand back BHA. 9. RU Open Hole Wireline and run Logging Suite. 10. Run and cement the 4 -1/2" Completion Liner. Test liner and packer to 2000 psi. 11. TOOH and LD drill pipe. 12. Run 4 -1/2" Completion String. Stab into the liner tie -back. 13. Rig down and move off 12/12/08 6 of 41 1 0 • Stegodon 24 -6 -8 DIR /LWD FORM DEPTH- RKB(21') Est. El. GL 483' HOLE CASING MUD INFO MWD MD I TVD TVD DEPTH -RKB 21 SIZE SPECS Cement Info INFO 0' 0' 483' 16" 651b/ft, L -80 16" Conductor 180' 180' 303' I . ,.' N/A N/A _WD /GR /RES /Sonic I I $urface Csq £ 9 -5/8" lu PI,' 40.0 Ibs/ft 27 Bbls, 366 sx Wellbore Stability L -80, BTC -M 10.7 ppg Lost Circulation Base PF 1,338' 1,338' -834 ID. = 8.835" .1 ft3 /sx Hole Cleaning Top of Tail Cement II Casing Sections Int. Yield 5750 psi i'I fly Collapse 3090 psi � Casing Wear Prince Creek A 1,339' 1,339' -835 ,g,::;::::. "} Tit 1 £ i N ail slurry S t l ' 50 Bbls, 243 sx o- ii ii r { 15.8 ppg Top of Liner i i Hanger 1.16 ft3/sx & Packer Assbly 1,700' 1,700' - 1,196' E € : € i 4 -1/2" Landing Collar ! A , z I, ` ' - 9.0 - 10.0 ppg 9 -5/8" Casing 1,850' 1,850' -1,346' ' : `' 333 ' if 12-1/4" 60 o F Wate Based Mud • LWD /GR /RES /EcoSco e 1 ft z P 44£ €,z% z t i €€ Inter. � ,E� � � � ; Dead Slurry Wellbore Stability s Lost Circulation 4-1/2" 161 Bbls, 366 sx POI Hole Cleaning Of 1 - 1� y 3 E £ I£ 12.6 #/ft 112.5 ppg t # = L -80, IBT I ££ t . l # € Torque &Drag E £ z 3 # kFt I D. = 3 958" F.36 ft3 /sx Schrader Bluff A 2,696' 2,696' - 2,192' ti I Int. Yield 8430psi 1 n a � € � �( Collapse g t Casing Sections ff � t f Er f E# 7500 psi f tF Schrader Bluff B 3,503' 3,503' - 2,999' ES ' £$ €f I ii I E I Mirth Tail Slurry 1 u€ # I P R I 1 �€ 72 Bbls, 346 sx Schrader Bluff C 4,102' 4,102' - 3,598' E ` # # g# " i 4 15.8 ppg i Keg .17 ft3 /sx RCI Sampling Coleville 4,249' 4,249' - 3,745' £� ix €E € ' g' : € €� :} 0 - 9.4 ppg 4 -1/2" Liner 5,000' 5,000' - 4,496' I , } . #f "€ 8 -1/2" 85�F Wat Based Mud 12/23/2008 Halliburton BAROID Chevron Mud Program chevron IWO White Hills Stegodon 24 -6 -8 Baroid Mud Program Halliburton Baroid Name (Printed) Signature Date Originator Dave Soquet Reviewed by Dave Higbie Customer Approval Walter Quay Version No: Date: 1.0 December 8, 2008 Stegodon v 1.0 1 12/8/08 12/12/08 8 of 41 • Hailiburton BAROID Chevron M d Program Stegodon 24 -6 -8 General Discussion This exploration well will be drilled from an ice pad south of Kuparuk. Due to the remo le location, waste • management is critical on this well. A 12 -1/4" surface hole will be drilled vertically to = depth of —1,950' where 9 -5/8" casing will be set and cemented. An 8 -1/2" production hole will then be d illed vertically to a depth of — 5,000'. After logging the production interval, a 4 -1/2" liner will be run and cem -nted. Spud the well with a conventional gel -based spud mud system Our primary focus for s rface hole drilling operations will be adequate mud weight for well control and sufficient mud viscosity and flowrates for efficient hole cleaning. A mud chiller will be utilized to minimize thawing of the pe mafrost and hole washout. • A new fresh water, 6% KCI / PHPA / Clayseal system with calcium carbonate will be uses for the production interval. The calcium carbonate will provide bridging and additional filtrate co trol in an attempt to reduce filtrate invasion into the wellbore. • Special Considerations: i. While gas hydrates are unlikely, maintain a sufficient quantity of Driltreat (lecithin) o accomplish a 2 ppb treatment in the event gas hydrates are noted. Contact the Technical Represe tative prior to any additions of Driltreat. ii. Lime and zinc carbonate should be on location for H2S contingency ( @1 pallet No Sulf and 2 pallets lime). iii. Maintain an adequate barite supply (and other necessary products) to increase the mud weight of the current circulating volume by 1.5 ppg at any time ( @1500 sx barite on location at all irises). iv. Due to the remote nature of this location, maintain an adequate supply of LCM -nd the other mud additives, which may be required to support this drilling program. v. Sticky clays have been problematic in the area. Maintain Dril -N- Slide /Condet at a otal concentration of —1% to minimize screen blinding and the agglomeration of the clays. vi. Reduce the potential for hole erosion /destabilization, hold the jet velocity belt 200 fps while achieving pump rates to deliver AV's around the drill pipe in the 150 -200 fpm range. vii. Some shale instability has been noted on offset wells (maintain tight filtrate control/ ud weight). viii. Obtaining good logs and fluid samples are a key component of this drilling progra . Maintaining low filtrate and using the inhibitive mud system will limit fluid invasion and help drill a gauge hole. ix. Maintain an adequate supply of STEELSEAL should losses be observed. String 3 -5 sx/hr immediately after noting losses. Again, this may also improve the post well fluid samples by Ii iting drilling fluid invasion. Well Specifics: Casing Program MD TVD Footage 12 -1/4" hole (9 -5/8" casing) 1,950' 1,950' 1,950' 8 -1/2" hole (4 -1/2" liner) 5,000' 5,000' 3,050' Stegodon v1.0 2 1 2/8/08 12/12/08 9 of 41 • Halliburton BAROID Chevron Mud Program Surface Interval: 12 -1/4" to —1,850'; Spud Mud Mud Properties Initial Value Final Value Density (ppg) 8.5 9.0 - 9.4* Funnel Viscosity (seconds) 100 - 200 70 - 150 Yield Point 30 - 40 20 - 30 (cP) Plastic Viscostiy (lb /100 sf) 10 - 30 12 - 25 10 second Gel Strength (lb /100 st) 10 - 15 10 - 15 10 minute Gel Strength (lb /100 sf) 20 20 - 40 pH 9 - 9.5 9 - 9.5 API Filtrate(cc) Unrestricted <10 *Weight increase due to natural progression of solids. A weight up is not programmed. Surface Interval The surface interval of this well will be drilled with a conventional spud mud as formulate below: Base Formulation: Fresh Water - .982 bbl /bbl Aquagel - 25 ppb X -Tend II - .1 ppb (250 viscosity) Caustic soda - .2 ppb (pH 9 -9.5) Spud the well with maximum flow rates (600 gpm minimum assuming 12 -1/4" hole w /4" drill pipe) to ensure good cuttings transport. Target an initial YP in the 30 -40 range with a 100 -2 0 viscosity. After penetrating the upper gravels and the permafrost, gradually reduce the funnel viscosity to ca. 70 -150 sec as the hole allows. Reduce the API FL to under 12 cc /30 min with additions of Dextrid. At interval TD, pump a high viscosity or Barolift sweep and condition the mud for runring casing. Once the casing is landed, pre -treat the system for cement with a minimum of 0.5 ppb citric acid and 1.0 ppb bicarb. Add 0.25 -0.5 ppg Carbonox or Barathin to thin mud to target properties (converse with the cementers to see what properties they have based there design on). With an initial mud density of 8.5 ppg, please note the other issues of concern as listed I:elow: 1. Make sure all members of the drilling team are aware of the potential of encountering gas hydrates. 2. A mud weight increase is not currently programmed for drilling the gas hydrate interval of the well, if encountered. 3. If gas hydrates are noted, treat the system with 2.0 ppb of Driltreat (Lecithin) aid 1 /2% by volume Dril -N- Slide. Some defoamer additions may also be necessary to help the gas break out. 4. Maintain the mud as cool as possible (40 - 60 °F if possible). Efforts to keep the fluid cool include mudding up with cold water, diluting the mud with cold water, and utilizing a mud chiller. Stegodon v 1.0 3 12/8/08 12/12/08 10 of 41 • • Halliburton BAROID Chevron Mud Program Mud maintenance issues for this interval of the well are as follows: 1. Use Aquagel and X -Tend II for viscosity and YP requirements. Initially target a viscosity of 100 -200 range, allowing it to gradually decrease as the permafrost is exited. 2. Use Dextrid for API filtration control. No filtrate control is planned initially, but drop the fluid loss to the 12 cc range prior to exiting the permafrost. 3. Hold the pH in the 8.5 -9.5 range with caustic soda. 4. DriI -N- Slide /Condet additions will be required to minimize screen blinding. Maintain a total concentration of 1% v /v. 5. Control penetration rates based upon the ability of the surface system to process the drilling mud. 6. Daily additions of X -Cide 207 will be necessary to control bacterial action after adding Dextrid. 7. Minimize dilution requirements and keep the mud as clean as possible through aggressive use of solids - control equipment. 8. Once casing is on bottom, thin the mud with Carbonox or Barathin to minimize channeling and improve the cement job. A strong focus on minimizing waste needs to be in place before and while drilling all sections of this well. Do not jeopardize the integrity of the fluid system; however, all efforts need to be made to this end. Allow the pit volume to deplete prior to TD on the surface hole. This will leave more room in the pits for displaced mud when cementing. Ensure all solids control equipment is working properly prior to spudding. Utilize shakers, desanders /desilters, mud cleaners and centrifuge(s) to reduce solids and reduce dilution. No processes should take place that will lead to a build up of low gravity solids in the mud. Build and maintain the system with COLD water. All attempts to keep the temperature of the mud 40 — 60 °F should be made. A mud chiller will be utilized to minimize thawing of the permafrost and hole washout. Normal surface hole viscosities should be adequate for this vertical well. Maximum flow rates should be used to ensure good cuttings transport. Target an initial YP in the 30 -40 range then adjust as dictated by the actual hole cleaning requirements of the well. However, do not hesitate quickly raise the viscosity if hole cleaning problems develop. Aquagel and X -Tend II additions should be utilized to provide rheological support as needed. Utilize high viscosity sweeps to supplement the hole cl aning capabilities of the system. On Smilodon, it was noted that adequate flowrates were not achieved due to shak r screen blinding. Maintain Dril -N -Slide /Condet at a total concentration of -1% to minimize screen blinding and the agglomeration of the clays. It is important to exercise caution to minimize the potential for creating a situation of lost circulation. Tripping speeds and casing running speeds should be slowed to reduce the effects of surge pressures on the formation especially with this elevated rheology. Do not attempt to run casing if the well is not in stable condition. Pumps should be "staged" on line slowly to avoid surging the hole and the pipe rotated to break the mud's gels before turning the pumps on. While tripping out of the Panthera surface hole, significant tight spots, packing off, and lost circulation were encountered resulting in stuck pipe and the inability to run casing. This was likely due to running gravel and the resultant increased hole diameter. Pay careful attention to detect any pctentially sloughing gravel early. Stegodon v1.0 4 12/8/08 12/12/08 11 of 41 • Halliburton BAROID Chevron M d Program Production Interval: 8 1 /2" to 5,000'; 6% KCI /PHPA/Clayseal with Calcium C • rbonate Mud Properties Initial Value Final Value Density (ppg) 9.1 9.5 max * Funnel Viscosity (seconds) 45 - 70 45 - 70 Yield Point 15 - 25 15 - 25 (cP) Plastic Viscostiy (lb /100 s f) 10 - 22 12 - 24 10 second gel 4 - 4 - 10 minute gel 6 - 13 6 - 14 pH 9 - 9.5 9 - 9.5 API filtrate <3.5 <3.5 Solids % <6 <6 * Unless hole conditions dictate otherwise Base Formulation: Fresh Water - 0.911 bbl KCI - 20 lbs (30 -32K ppm chlorides) EZ Mud DP - 0.75 lbs (.15 ppb in initial mix) Clayseal - 0.84 gal (none in initial mix) Dextrid - 3 lbs (API filtrate <3.5 cc) Barazan -D - 1 -2 lbs (as required for an initial 20 YP) KOH - 0.1 -.25 lbs (pH = 9 -9.5) Baracarb 5 - 9 lbs Baracarb 25 - 9 lbs Baracarb 50 - 12 lbs DriI -N -Slide - 1.0% v/v X -Cide 207 - 0.25 lbs Baracor 700 - 1 ppb Barascav D - 0.5 ppb (to be added at the rig when first circulating ** Use Barite or Baracarb for any needed weight ups on this well. NOT drill solids. While drilling, gradually increase the EZ Mud DP until the full 0.75 ppb is reached. On e the full EZ Mud concentration is reached, begin to gradually add Clayseal to a final concentration of 0.:4 gal /bbl. Ensure the shakers can handle a flowrate of 450 gpm at all times while increasing the EZ ud and Clayseal concentrations. Once the full concentrations are achieved, maintain them until interval D. Decrease the API filtrate to <3.5 cc /30 for the interval using Dextrid and /or PAC L. Kee. low gravity drilled solids to a minimum ( <6% by volume if possible). Maintain the MBT at <12 ppb through dilution and solids control. Maintain the pH between 9.0 -9.5 with KOH. Daily additions of X -Cide 207 -hould be made to control bacterial action. The chloride level should be kept in the 28 -34K range through additions of KSI. The EZ Mud concentration should be maintained at .75 ppb. A 15 -25 YP should be maintained using Barazan D +. Extremely sticky clays were noted on the Smilodon well. Maintain —1% Dril -N -Slid= in the system to combat screen blinding from sticky clays. Condet additions can also be made to com • at screen blinding and clay agglomeration. The system will be weighted to 9.1 initially. Maintain the Baracarbs in their recommen•ed concentrations for effective bridging. Expect a natural weight progression as drill solids build up in t e fluid. Maximize Stegodon v 1.0 5 12/8/08 12/12/08 12 of 41 • Halliburton BAROID Chevron Mud Program solids control usage and anticipate additional Baracarb additions when running the centrifuge to control drill solids. Do not allow the mud weight to increase over 9.5 ppg. If necessary, use wiole mud dilutions to keep the mud weight in range. A 15 -25 YP should be maintained using Barazan D +. Periodic sweeps should be pumped and monitored to gauge their effectiveness. Special efforts should be made to keep ECD's and surge /swab pressures to a minimum. This will reduce the chances of lost circulation and also reduce damage to the exposed shales. If seepage losses are noted while drilling the sands, immediately string in STEELSEAL at 3 -5 sx/hr. Obtaining good logs and fluid samples are key goals of the well. Tight hole can be anticipated for the first time tripping through new hole after it has been drilled. If backreaming becomes necessary, extreme caution must be used to avoid the potential for packing off and stuck pipe. Extended circulating times may be required to remove cuttings from the hole and minimize cuttings loading in the annulus. Mud plant support is available for this well. All efforts must be made to keep the mLd system in good shape and maintain the mud weight as low as possible. Should whole mud dilution ba needed, contact the mud plant well in advance to plan for any needed whole mud requirements. Stegodon v 1.0 6 12/8/08 12/12/08 13 of 41 • • Halliburton BAROID Chevron M d Program Recommended Drilling Parameters: Penetration Rates: Please see the following optimization chart for maximum allowable penetration rates. T ese rates are set for rotating not sliding. Penetration rates might need to be controlled to minimize overt.ading the annulus with cuttings. Close monitoring of PWD data will assist in diagnosing this potential probl-m and allow real - time, timely remedial actions. Due to the vertical profile of this well, rpm has little effect • n hole cleaning. Hydraulics Optimization Chart Actual P rates will need adjusted to how well the surface equipment can handle the flow =nd cuttings. 12 -1/4" Maximum Acceptable ROP in fph at Specified GPM and RPM GPM—> 500 600 700 60 rpm 141 194 223 80 rpm 141 194 _ 223 8 -1/2" Maximum Acceptable ROP in fph at Specified GPM and RPM GPM—) 300 400 500 60 rpm 159 251 333 80 rpm 159 251 333 Hole Cleaning: Maintaining the programmed flow properties is essential to the successful completion of this well. Any indication of a failure to keep the annulus clean of excess cuttings (drag, torque, partial pack offs) should be countered by increasing the circulation time on subsequent connections and prior to t ips. Pipe rotation should also be used in conjunction with the pumping of high viscosity sweeps. If these sweeps seem ineffective, other type sweeps (Barolift, weighted, etc.) should be tried. The return at surface of all sweeps should be monitored at the shakers to gauge their effectiveness. When circ lating bottoms up prior to POH, it is advisable to pull one stand every half hour to reduce the hole ashout effects of circulating over one short interval. Waste Minimization: 1. Solids Control Equipment — for reduced dilution volume. Monitoring shaker screen mesh size and checking for screen damage (holes) is a pri ary responsibility of both the fluids engineer and rig contractor. The centrifuge must be r n as much as possible to reduce dilution throughout all hole sections. 2. Gauge Hole — for reduced cuttings volume. • Inhibitive Mud System — Use of 6% KCI /PHPA/Clayseal system as outlined in the mud program to reduce washout in clay /shale sections of the production interval • Hydraulics and Rheology as recommended in the mud program to reduce washo is in unconsolidated formations, especially on surface hole. • Use of near freezing water for mud make -up and dilution to reduce thawing of Pe mafrost. Note: the close proximity of heat generating equipment (power plants) to the mud pits on some rigs can increase the surface mud temperatures by 10 to 15 deg F while drilling surface hole. • Drilling the surface hole and running casing as efficiently as possible to reduce tine, thus thawing and washout of the Permafrost. Tracking and Reporting of Waste Streams and Costs: Stegodon v1.0 7 12/8/08 12/12/08 14 of 41 • Halliburton BAROID Chevron Mud Program We consider this to be of vital importance. TFM reports will be completed daily. Interval and well summaries will also be done. Lubrication: Due to the vertical nature of this wellbore, lubricant support is not anticipated. If regjired, 1 -2% of EZ Glide or Torq Trim II can be added. Risks and Contingencies: Lost Circulation: Preventing the initiation of lost returns should be a primary goal of the drilling fluid in the production zone. To that end the rheology of the system has been reduced while still providing ample hole cleaning. Maintaining a low ECD while circulating, and eliminating high pressure spikes while tripping, will both go a long way toward reducing the risk of lost returns. Should lost returns occur check wits MWD personnel prior to pumping any pills to assure that no plugging will occur. Wellbore Instability: Some splintered shale was noted on Smilodon. Ensure the mud has tight filtrate control and minimize mechanical disturbance of the wellbore. Should any signs of shale splintering be seen immediately raise the mud weight a minimum of 0.4 ppg. Stuck pipe: Two forms of stuck pipe are possible. One is from hole pack -off as related to poor hole cleaning. Stuck pipe can occur if the hole isn't clean or if the wellbore exhibits severe instability. The best cure is to pro - actively prevent the occurrence of either scenario, and one does occur, correct drilling practices must be employed. If pulling up into a tight spot, do not jar up further, but attempt to get below the problem. Backreaming is an invitation to packing off and resulting stuck pipe so backreaming must be done with care and only when necessary. If stuck pipe occurs across a sand zone and there are indications of differential sticking, there are drilling fluid solutions. If possible, reducing the fluid density by a minimum of 0.5 ppg may provide some relief. Stegodon v1.0 8 12/8/08 12/12/08 15 of 41 • r Haillburton BAROID Chevron M d Program 12 -1/4" Surface — Modeled hole cleaning °pa adtenm Rig 1% : SpudMud _... 15169ZCADgloll :arhadorNa6ors WelSkgodm; How Bale =600gaVmn_.....__.._ 1101 11 1533XCtfl EN Cuttings lraz pal Average Hae (CD MudWeiji.9.36Ngal CAI Dia =.bi Load.% ED % V,ft) Angle Ngal H•lifWilth pm /HC60rxemlC I/ 1.88 __,.. _.._. � C w1oG1 ,. nIG1 M'. s t � ; I I', { I I �I I I I j I1 !' s 1 ' 1 I I <., 4.030159201 , ' 1, ;,:i ' , ; ! 1 , \: ! i ! 1 44 -:-, ! I � 4 v j Y : j 1 :I jl' • 31 f[ 'I : 7: ' : is 1 Ile t 1 .' If. II ■ , i ; 1 .:, ,: H . , I 1 L w H' 12%i) % 4. x 2%3 x 200081 1$80 5881g __._. . 9119/9 71 h/gd 8. x 2613 x 1E0 81 291 1 2010.0 5 10 15 20 25 0 50 1 0 65 111 3 . 0 90 933 91 1030 .1hCU1haa Good hole cleaning can be achieved with 600 gpm at 100' per hour. Baroid does not ref ommend drilling at rates above 150' /hr on surface. Elevated penetration rates may cause problems with `clay chunks " / clay rings plugging off the flowline and causing pack offs. Stegodon V 1.0 9 1 2 /8 /08 12/12/08 16 of 41 i 0 1 Halliburton BAROID Chevron M d Program 8 -1/2" Production — Modeled hole cleaning OP Demo Rig 101 6Lfl[1IPHPAI[ eaIONN _._...._ l.q]f i l .utdnr.Nabws Wet Slgodm„ FltrNde 400gahm _....._, ....._. ? l�fih - 1.478Xf dpgE6 Di*: Irrapod Average Role M�Wa�I CulfigDa =.15 _ ..... _ F�1s @1 d% _ EN % V.IVm . _. .�._. __ .44 . __ dD I 1:IHC•E M3mi Dill Loa 18 wlofil ; ■ w/ Di ' 1 1 a 1000 __ _.. —, -_ , ' P.1';:';".4.!':.111:'': iz ' I I '_ ? 1" 1 1 %11100 v 170 r ... .n.. 1 . , ► ' t, ! Ifx334x4587.dfl ft: i i t. '''' ' ., ppyy� I dR ,V® 1 i E t x 1 . ! 1 , ' X � 1 I fI ;; , 1 ` v,` 4'16)5751 e1D10R 11 "1 100 , 1 z 21 v 9: 0 " " .03 i j ik x83QOfl 1 �� — xF _ _ 05n a ° ` 0,000P6111 v � . r1D1D 4'„ t9R1 N• 5 10 15 20 i5 0 50 100 0 184 3 7 30 6D S9 9D 980 108] .511 COI fee Excellent hole cleaning is achieved at 150 fph at 400 gpm. Pump rates over 600 g , •m cause a sharp increase in ECD and are not necessary to clean this hole section. Stegodon v 1.0 10 12/8/08 12/12/08 17 of 41 Chevron - kill''' tiat Sc bl u m b or g er Stegodon 24 -6 -8 (P1) Proposal Report Date: December 4, 2008 Survey 1 DLS Computation Method: Minimum Curvature / Lubinski Client: Chevron Vertical Section Azimuth: 90.000° Field: White Hills Chevron Vertical Section Origin: N 0.000 ft, E 0.000 ft Structure / Slot: Stegodon 1 Stegodon 2008 StUdY TVD Reference Datum: Rotary Table Well: Stegodon ® TVD Reference Elevation: 504.00 ft relative to MSL Borehole: Stegodon 24 -6 -8 ® ® Sea Bed / Ground Level Elevation: 483.00 ft relative to MSL • UWIIAPI #: 50 Magnetic Declination: 22.287° Survey Name 1 Date: Stegodon (P1) / December 4, 2008 Total Field Strength: 57581.105 nT Tort 1 AHD / DDI 1 ERD ratio: 0.000° / 0.00 ft/ 0.000 / 0.000 Magnetic Dip: 80.438° Grid Coordinate System: NAD27 Alaska State Planes, Zone 04, US Feet Declination Date: July 02, 2008 Location Lat/Long: N 69.86485973, W 150.03244097 Magnetic Declination Model: BGGM 2008 • Location Grid N/E Y/X: N 5800028.880 ftUS, E 495909.600 ftUS North Reference: True North Grid Convergence Angle: - 0.03045829° Total Corr Mag North .> True North: +22.287° Grid Scale Factor: 0.99990002 Local Coordinates Referenced To: Well Head Measured Vertical Mag /Gray Directional Comments Depth Inclination Azimuth Sub•Sea TVD TVD Section NS EW Tool face DLS Difficulty Northing Easting Latitude Longitude (ft) _ (deg) (deg) (ft) (8) (ft) (ft) (ft) _ (deg) (deg /100ft ) Index (ftUS) (ftUS) RTE 0.00 0.00 0.00 - 504.00 0.00 0.00 0.00 0.00 - 0.00 0.00 • 5800028.88 • 495909.60 N 69.86485973 W 150.03244097 GL 21.00 0.00 0.00 - 483.00 21.00 0.00 0.00 0.00 - -- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 200.00 0.00 0.00 - 304.00 200.00 0.00 0.00 0.00 -- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 400.00 0.00 0.00 - 104.00 400.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 MSL 504.00 0.00 0.00 0.00 504.00 0.00 0.00 0.00 -- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 600.00 0.00 0.00 96.00 600.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 800.00 0.00 0.00 296.00 800.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 1000.00 0.00 0.00 496.00 1000.00 0.00 0.00 0.00 -- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 Prince Creek A 1148.00 0.00 0.00 644.00 1148.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 1200.00 0.00 0.00 696.00 1200.00 0.00 0.00 0.00 -- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 1400.00 0.00 0.00 896.00 1400.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.0324 Base Perm 1491.00 0.00 0.00 987.00 1491.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.0324 1600.00 0.00 0.00 1096.00 1600.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244 1800.00 0.00 0.00 1296.00 1800.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 9 -5/8" Csg 1950.00 0.00 0.00 1446.00 1950.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 2000.00 0.00 0.00 1496.00 2000.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 :.:: - 200.00 0.00 0.00 0.00 - 0.00 0.00 ;000020.00 49io910.00 N 691G405973 W 150.03244097 2400.00 0.00 0.00 1896.00 2400.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 2600.00 0.00 0.00 2096.00 2600.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 SchraderA 2617.00 0.00 0.00 2113.00 2617.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 2800.00 0.00 0.00 2296.00 2800.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 3000.00 0.00 0.00 2496.00 3000.00 0.00 0.00 0.00 -- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 WellDesign Ver SP 2.1 Bld( docA0x 100) Stegodon 2008 \Stegodon\Stegodon 24-6 -8 \Stegodon (P1) Generated 12/8/2008 2:09 PM Page 1 of 2 12/12/08 18 of 41 1 Measured Vertical Mag /Gray Directional Comments Depth Inclination Azimuth Sub -Sea TVD TVD Section NS EW Tool Face DLS Difficulty Northing Easting Latitude Longitude - (ft ) (deg) (deg) (ft) (ft) (ft) (ft) (ft ) (deg) (deg /100ft) _ Index _ (ftUS) (ftUS) 3200.00 0.00 0.00 2696.00 3200.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 Schrader B 3277.00 0.00 0.00 2773.00 3277.00 0.00 0.00 0.00 -- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 3400.00 0.00 0.00 2896.00 3400.00 0.00 0.00 0.00 - -- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 3600.00 0.00 0.00 3096.00 3600.00 0.00 0.00 0.00 -- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 3800.00 0.00 0.00 3296.00 3800.00 0.00 0.00 0.00 - -- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 Schrader C 3943.00 0.00 0.00 3439.00 3943.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 4000.00 0.00 0.00 3496.00 4000.00 0.00 0.00 0.00 -- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 4200.00 0.00 0.00 3696.00 4200.00 0.00 0.00 0.00 - -- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 4400.00 0.00 0.00 3896.00 4400.00 0.00 0.00 0.00 -- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 4600.00 0.00 0.00 4096.00 4600.00 0.00 0.00 0.00 - 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244097 4800.00 0.00 0.00 4296.00 4800.00 0.00 0.00 0.00 -- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.03244 7 TD / 4 -1/2" , 5000.00 0.00 0.00 4496.00 .5000.00 0.00 0.00 0.00 --- 0.00 0.00 5800028.88 495909.60 N 69.86485973 W 150.032 Survey Error Model: SLB ISCWSA version 24 * ** 3 -D 95.00% Confidence 2.7955 sigma Surveying Proq: MD From (ft) MD To ( ft) EOU Freq Survey Tool Type Borehole -> Survey 0.00 21.00 1/100.00 SLB_MWD- STDAA1 -Depth Only Stegodon 24 -6 -8 -> Stegodon (P1) 21.00 1950.00 1/100.00 SLB_MWD- STDAA1 Stegodon 24 -6 -8 -> Stegodon (P1) 1950.00 5000.00 1/100.00 SLB STDAA2 Stegodon 24 -6 -8 -> Stegodon (P1) Legal Description: Northing (Y) fftusl Easting (X) fftUSI Surface : 1004 FNL 1630 FWL S24 T6N R8E UM • 5800028.88 495909.60 BHL : 1004 FNL 1630 FWL S24 T6N R8E UM 5800028.88 495909.60 • WellDesign Ver SP 2.1 Bld( docA0x_100) Stegodon 2008 \Stegodon \Stegodon 24 -6 -8 \Stegodon (P1) Generated 12/8/2008 2:09 PM Page 2 of 2 12/12/08 19 of 41 Chevron • 1%10 Sc Iumberger 11 11110 WELL FIELD MIXTURE Stegodon (P1) White Hills Chevron Stegod• n Magnetic Parameters Surface Location 98027 4)0.4. State P4.nes.2ane 04. US Feet Miscellaneous Medal: EIGGM 2005 Date: Arty 02, 2008 Lat: 1469 51 51456 Mathew SSWE2tB8SUS 0,14 00,0: 003046529 Slat 00908012009 7VD RIF Ratery Table (5040011 above 1451) Mao Dec .22 267 FS 57581.1 87 Lon: W150 156 787 Seating: 456209 50 ItUS Scale P102 0308800019 Plan: SeapoOon (Pt) Snry Date. December Oa. 2008 -1200 -600 0 600 12.0 0 0 SL• 600 600 • !ince ereek A 1200 1200 8058 Pemi 1800 1800 . L 9-5/8" Csg 2400 2400 it 0 -chrader (.) 3000 3000 " .chraderB 3600 3600 -chrader C 4200 4200 4800 4800 . L TD (4-1/2" tegodon (P1) 12/12/08 20 of 41 -1200 -600 0 600 1200 Vertical Section (ft) Azim = 90°, Scale = 1(in):600(ft) Origin = 0 N/-S, 0 E/-V REV DATE BY CK APP • DESCRIPTION REV DATE BY a APP DESCRIPTION 1 DEC 08 RRM KWA UPDATED SECTION \ LINE OFFSETS STEGODON 24 -6 -8 DRILL PAD _! LOCATED WITHIN PROTRACTED =- -4 - ' SEC. 24, T 6 N, R 8 E, i UMIAT MERIDIAN. 1004' F.N.L, 1630' F.W.L. ASP ZONE 4 k , STEGODON NAD 27 COORDINATES _ 24-3-8 LAT = N 69' 51' 53.4950" ..� 24 • LONG = W 150' 01' 56.7875" "" - Y = 5,800,028.88' ..t,,,,„ " X = 495,909.60' _ ' _- .,,,.. w '65 NOTES: ct i -- T 6 1 1. COORDINATES SHOWN ARE NAD 27 ALASKA - -- _- ___. -.0 __._ STATE PLANE ZONE 4. 2. GEOGRAPHIC COORDINATES ARE NAD 27. VICINITY MAP 3. ALL DISTANCES ARE GROUND. 1" = APPROX. 1/2 MILE 4. PAD IS ROTATED 20' WEST FROM NORTH. USGS QUAD: 5. VERTICAL DATUM IS GPS DERIVED BASED ON UMIAT D -1 GEOID 06. Epp k N 1° / f / N r STEGODON / co -s 24 -6 -8 0 A l i _ o r j / LEGEND W bpd 5 �p —IN- DENOTES SPILL TRAJECTORY STAKED ; ONDUCTOR LOCATION LOUNSBURY STEGODON 2 DRILL PAD /I\ & ASSOCIATES, INC. SC ALE: SURVEYORS ENGINEERS PLANNERS 1 " = 200' 'yob 907-272 -5451 CHEVRON STEGODON 24 -6 -8 DRILL PAD AS— STAKED DRAWING UNION OIL OF CAUFORNIA WITH TOPO AND SPLL TRAJECTORY CADD F 1*Qg DRAWING NO: SHEET: 21 of 4REV: STEGOOOtf 2 4 SEPTEMBER 2008 06- 025 /2008_SURVEY /DRAWINGS /STEGODON 2.DWC 1 OF 1 ro Stegodon Chevron Depth vs. Time Mob Rig /RU —�— Stegodon Actual —♦— Stegodon Plan 0 • • It • 2 -1/4 "Hoe SPUD 1000 — • ng 2000 8 -1/2" Hole 63000 -1/2" Liner /P &A A ' _ 4000 • 5000 • • Loggi g 6000 0 5 10 15 20 25 30 35 40 45 50 Time (Days) 12/12/08 22 of 41 Calculation & Casing Design Factors Chevron Stegodon 24 -6-8 White Hills Exploration WELL: Stegodon 24-6 -8 FIELD: White Hills DATE: 10- Dec-08 DESIGN BY: W. Quay Sect. 1 12 1/4" hole MUD WT. 9.5 PPG MASP= 0 Diverter Sect. 2 8 1/2" hole MUD WT. 9.3 PPG MASP= 969 psi TENSION MINIMUM COLLAPSE COLLAPSE WEIGHT TOP OF STRENGTH PRESS @ RESIST. MINIMUM DESCRIPTION W/O BF SECTION TENSION WORST CASE BOTTOM w/o TENSION WORST CASE MASP YIELD WORST CASE • SECTION CASING BOTTOM TOP LENGTH WT. GRADE THREAD LBS LBS 1000 LBS SF TENSION PSI` PSI SF COLL. PSI" PSI SF BURST 1 9 -5/8" 1,850 0 1850 40 L -80 BTC 74,000 74,000 916 12.38 836 3,090 3.70 969 5,750 5.93 TVD 1,850 0 ' Collapse pressure is calculated; Normal Pressure Fluid Gradient for external stress (.452 psi /ft) and the casing evacuated for the internal stress (0 psi/ft) "` See attached sheet for calculation of MASP • 12/12/08 23 of 41 • • % Che Maximum Anticipated Surface Pressure Calculation Stegodon 24-6 -8 White Hills Exploration Assumptions: 1. Based on offset drilling data & G &G evaluation and analysis, the pore pressure gradient i. predicted to be a a normal 0.433 psi /ft gradient from surface to planned total depth at 5000' TVD BRT. 2. The M.A.S.P. during drilling operations will be governed by the 9 -5/8" shoe frac gradient, :nd is calculated based on a full column of gas between the 9 -5/8" shoe and the surface. With the shoe for Stegodon at 1850' TVD, the Leak -off is anticipated to be —12 ppg EMW. 3. The M.A.S.P. during production operations will be the estimated SIBHP minus the gas hy',rostatic pressure between TD & the surface. M.A.S.P. Drilling 8 - 1/2" Hole at 5000' TVD Max. pore pressure at T.D. = 5,000 ft. x 0.433 psi /ft = 216 psi M.A.S.P. = 2165 psi - ( 0.1 psi /ft x 5000 ) = 166', psi Or Max. At Casing Shoe = 1,850 ft. x 12.0 ppg = 115 psi M.A.S.P. = 1154 psi - ( 0.1 psi /ft x 1850 ) = 96' psi 12/12/08 24 of 41 • • • Chevron Diverter Schematic Date - October 17, 2007 Location - White Hills - North Sipe ill/Wl. Rig - Nabors 106E t, ,, ,,, ,, em. Stack: Size 13 5/8" Pressure Rating - 5000 PSI Annular: Hydril 13 -5/8' GK t$ ti t tttt t °1 ` tlt tIIt tit - b Double Gate BOP Deactivated Drilling Spool , -FS '1* 11 7,7 Single Gate BOP Deactivated Knife Valve: 12" Diverter Line • 12/12/08 25 of 41 Z. 1200(1001 it !' Frl1= r , • lilt -d71 I 11 mo= = i1 1 • _ AIL _ I� 1. If ' i alma. 111 I•�: I�I� 7 I ' i� ( _ �. <. g �, i t is ► ■1�1��1� II►! 141171- . f � ■ f ■1 -I BUILDING 1 I_il■i I, �■a■l unili lghlilml , ; , .. ni —� it �.. EN rill limi ibli gi�it _d i�l I ,! 7 ,I� T i� BUILDING 2 _��I�p� • II .� ®� w� - - ■�= • . ,_ 1 .11 1 1 I� ■1 I■ v �iri 11��1swwew �1 f � / �r'i� -��i1 ■1 - I BUILDING 3 1_ ■I0 1 I� ®�I�i illElm= 1 1 !I n. —N �j1 Mtn-_ � : Eimmiii� Imiimi I gdii � r g al! ! ■ � ± is � , ��" it ■I�I��I�1 ■I � � __ -- , iait�r 1iiar It 'fq ' ■h r. ■ICI I� ■ 151111= O 01:= i) BUILDING 4 ' I 1IM1 i1 " _ -,. II III I E.1111 BUILDING 5 EMI II • ( I, BUILDING 8 HELI RIG 106 - DIVERTER LINE LAYOUT 14 • Chevron ONO BOP Schematic Date - October 17, 2007 Location - White Hills - Nort North Slpe Rig - Nabors 106E Stack: Size - 13 5/8" Pressure Rating - 5000 PSI iiIu!t i Wart ins — Annular: l pdril 13 -5/8" GK tifit , Double Gate BOP Shaffer 13 -5/8" SL Drilling Spool ti 3€2iF Single Gate BOP Shaffer 13 -5/8" SL aiit fxtt;SBSt Blanked Off Diverter Outle: i�D39Bt i tz € s_i�ii. i'11131 141t ; P� i tliit F3 12/12/08 27 of 41 \ABORS DRILLING a i . .. __ T T .Qo CC (min, elm BB - : � / � • *0 :I Q ; : 1 3 IV : 0 0° K :1Te7 1 ) itiok041.. — tg' 7 VIEW ; ate. AA - .!�ciP1. e, r 4Ilit lii: row away dare r ift Ph /45(..> ? 1111 . 1 ._: 110 c � ^ � � � K � ` � ( VIEW ( VIEW VIEW ® �r CC _ - - AA BB Scale: Date: Description: N.T.S APR 11 2007 3 -1/8" 5,000# NACE Drawn by: DWG# RAVI MANI NDR #106 TRIM CHOKE & KILL : MANIFOLD SYSTEM Checked REV ' a by: 00 PACIFIC VALVE SERVICES INC. • Chevron LEAK OFF TEST PROCEDURE 1. Clean out the rathole below the shoe, and drill 20' of new hole. Circulate and condition mud. 2. Pull the drill string into the shoe. Rig up to observe annulus pressures. 3. Close the pipe rams and pump down the drillpipe at a slow rate (1/4 - 1/3 BPM) if exposed formation is permeable. A non - permeable formation should be step tested to a predetermined pressure. 4. Measure the volume pumped and plot annulus pressure -vs- cumulative volume pumped. Compare annulus pressure to drill pipe pressure and confirm both are the same. Record and plot pressure versus volume pumped. The pumps should be shut down immediately upon indication of leak -off. Record the inital, shut down pressure and the pressure after 1, 2, and 3 minutes. 5. Release pressure and record the volume of fluid recovered in the trip tank. The point "B" shown in the attached graph at which the plot of drillpipe pressure stops inc equally as the volume is pumped is called the P.I.T. limit, Leak Off, or pressure integrity test limit. The leak -off pressure is calculated as follows: Leak -off (EMW) = Mud weight in hole + P.I.T. (PSI) (0.052) X (shoe depth in TVD ft.) This equivalent mud weight should be made known to all drilling personnel to ensure it is nDt exceeded. See the drilling procedure for guidelines on expected LOT's or pressure integrity test limits for eaci casing shoe. C B � SURFACE PRESS. TYPICAL PIT PLOT (psi) A ' VOLUME PUMPED SHUT -IN -TIME (BBLS) (MIN) NOTES: Point "A" will have some variance until the system begins to pressure up. Point `B" is the leak off and is abbreviated LOT. Point "C" is known as the injection pressure and is usually dependent on rate. Point "D" is known as the fracture closure pressure and may not stabilize if permeable formations are exposed. 12/12/08 29 of 41 , • 0 Chevron U NOC b onta B o Company 4Pi Chevron North Am rica 'IWO Alaska Resources Exploration and Produc Houst n, Wil inent /Al Houston, TX 77009 North Slope Alaska White Hills Prospect SHALLOW HAZARD ANALYSIS STEGODON 24 -6 -8 CHEVRON ACREAGE aaF'- A din -us — X17 _ �,. LOId IS LAND F 57 ` rn#1 r *p HSTAR 3 I 2 -- eft " 1'� _ .a*O �p Xi 4. lE ► �-' 43 1 9 X11 .5e '; . . r ��:� • -.+ 7 N ,, ,.r `"4 , , �) _ �' .'-_ ` ,f. �, X 1 4 C' a t _✓ l ■ i i z +c' 4 Y icF � Lf' y ' i 1 r er v -++Y l 1 a 1 " „.ice ' �� ,, ` ,, 'I 4 t. -...,- i " � I ti;l . f ¢� ' � I C s i,J� s ky - ''-'',4) s 4x9 a - . .. �" \ ` , `t s��" . s , f `p ) - 12/12/08 30 of 41 • Chevron UNOCAL a Alaska Resources %11 10 Union Oil Company of California (UOCC), a wholly owned indirect subsidiary of Chevron Corporation currently has leased approximately 20 x 40 square miles of acreage on the Central North Slose of Alaska (Fig 1). UOCC holds a 70% working interest and TOTAL holds a 30% working interest in t e prospect which is bounded by the National Petroleum Reserve of Alaska (NPRA) to the West, the Trans - Alaska Pipeline (TAPS) to the East, Kuparuk River and Prudhoe Bay Fields to the North and the Brooks Range F•othills to the South. STRATIGRAPHY & RESERVOIR OBJECTIVES Ma SW Gubi k_Fm. NE ,, , .„ 4 ,„ 4 IF:4 , ,,-,.,-,., 4 , , ,v,,, 4 ' 1 40 ‘.■ n-5..."'—' ° d ad �i ®i•4 A`-°.�+,�a. - *.. : w 0 r 3 irk CRETACEOUS : „ ' il } Q - k; . - z - 7. - 1:q.- 7,0 . , ; .?' . ' Hue Shale I R • ra' zone . _ �k - - + ''7,r• I , N ` � , LTi , ill - ti . 'l I 0 ai J URAS I C '' i 1L1 208 s1 . �._ . -, y TRIASSIC L _ 245 lid -1 al W PERMIAN s y �r y t Cf.) PENNSYLVANIAN- 286' y LEsburne Group Z � m [ rSiS.SIPPCt�l . 4 MISSlSSIPPIAN Z PRE P; ; .4`” s MEGASEQUENCES * Allochthonous rock units Fig 2: White Hills Stratigraphy The Stegodon 24 -6 -8 well will target reservoir objectives in the shallow Tertiary throu o h Uppe at Cretaceous strata referred to as the Saganivriktok, Prince Creek, Ugnu and West Sak Formations sounded top by the permafrost and down to a total depth of approximately 5000 ft MD. Overall, the sequence records a regressive- transgressive cycle starting with the West Sak (Schrader Bluff) shallow marine prograding shelf sands, overlain by Ugnu fluvial - deltaic and then Non - marine Prince Creek and Sagay.nirktok clastic strata. . (From USGS Open -File Report 2005 -1182) 2 12/12/08 31 of 41 • • Chevron UNOCAL Alaska Resources % MO PRINCE CREEK FORMATION Saqavanirktok Group and Prince Creek Formation The Stegodon 24 -6 -8 well will spud in Tertiary generally upward- coarsening Sagavanir tok siltstones, fine to very-fine grained sandstones, interbedded bentonitic mudstones with minor lignite orizons, and gravels deposited under shallow marine to non - marine conditions. Below the Sagavanirktok Gro p are undifferentiated Prince Creek coarse clastic strata, comprised of gravels, coarse lithic sands, lignites, and siltstones. The Prince Creek sandstones typically exhibit 8 -30% clay content, with porosities to 38% and permeabilities to several darcies. UGNU FORMATION Uqnu Sands The Early Paleocene Ugnu Formation consists of upper -fine to medium and coarse grai ed lithic sandstones, siltstones, bentonitic shales, lignites, and some gravels deposited in a non - marine del a plain environment. The sandstones are poorly indurated to unconsolidated, with porosities exceeding 35% - nd to several darcies permeability. Heavy oil saturation is common 30 miles to the north in Kuparuk River, Mil e Point, and Prudhoe Bay fields. WEST SAK FORMATION West Sak Sands The West Sak consists of a shallowing upward shallow marine sequence comprised of v =ry fine- grained, single and amalgamated hummocky cross - stratified sandstone beds. The formation is typically characterized by fine to medium - grained, unconsolidated but well sorted sands interbedded with siltstones, udstones, and coals. The West Sak sands were deposited in a shoreface to proximal shelf environment. Low =r West Sak members were deposited in a lower shoreface to inner shelf setting by storm - generated waves -nd currents, both the upper and lower members showing good continuity both in the subsurface in areas with g•od control and in the outcrops to the southwest and south. The Stegodon 24 -6 -8 well will TD at the base of the West Sak Formation at approximately 5000 ft MD. 3 12/12/08 32 of 41 rl la . D O 0 O CA SD co T . N . (D W � s r (D 6s mi in d a y u. co cl) . N c° (a 1 ( p � ? i ', i i C! O 01 0 w i p .. i s # t ° 1 �� , p 4 :1 � � d � , 7 °i ( c4'. il,fi,..A Hill ,4*.Se)r .,, 5,(Do(-i3F0,13) (., gt a - F, -0 cn 0 ., E t ) ` i y 1 ! , ,,,,, G N n O Z O O O (p a r A Pf ` 0 ,� CD O a a L If � ft a + 3 1 1 / ` ts� ,cc, I 4 % it .3:3 t;thect tt,"„ 4' 6 d 4 4 ', „ 4 r.);.r` 3- \ 4 of 9, ' , tr,,...",„1 t , b y� w Y ` 1 2k ' J , i \ kF f i5i i�- . y i .4 1 1: 1 f(4�6 f ,��iMa Y # ,7a. (.1 n (D N 7 Q o O c m aa66 { .4 �- �f ' I l'',4114-' ` al 0 i • fn N— 3 OW ' t° r ° s A 4 �* i „t:::),;c:4,” .t.4'..;1,4 t '''i - A.' .)lifilli-A, O O O — —s Q } $ 9 � 4 ' a Y ! � ft1.1* ) ( 4 c 11)t ?,.? Co 0 , s . , ,fr, 0 C) tD • - n 4,4 r: 'y a k ,:. r r l a + ,p. _ FD' ,z., 4 i„, X - .4 i it • — cpv 5(uorn �. t) 14' � � , : JA-ii i*WiNviri c'D '00. ,0 4 Ili o . 5/1,°4- i 1 .4 o v 4 . 2T elf . cp _ '¢ , .a c° � r 41 . t,t. :44 1:4„.4.''; '17:: )) 1, s ' Q....toctI PrA: :'' :I'll .17,,,,;:it-44764,4t*„ '1..‘tv.?1,,'''1., -' ; ' ' I tt 1 $ 1,$ l'i.a, 4, Att. ,,,,„ ca �mvmv m QCn � ° � ,, A A A o f t � , , I . iii , ''c,' (O (D (p Q S O (7 -- ) � y } * i ' } # 1- q 4 a ' 4 ` ° m • 0 Chevron UNOCAL Alaska Resources GEOPHYSICAL DATA QUALITY 1P tca i1K -U3 .- st_A_ -A- 4114444UI �i LON ISL IDY F _ 5 , J .,�IK -71a UBIK1 'Oe a NTO t ". ' — i0 HSTAR3 Ni - y •C1 + �` r 9� LUBIK-• .p m S \ R!fi ______4. FLI. y � 3iR� I Pi O vi q "fir" BP ?1 11 ♦ F •'�' o • , i ,4 - _ . fi r � � is r . 7 -: - 4 y U • P'1 0& Y ti � yR r „ p b iii° r , :� , a ' NE; l'''' f 1 o a +., , - f h 4 -.. ' t • .J �� ,. ■ ∎ a1 -3 g � } CIRQUE 2 CIRQ { j " I � �� ms s ; GRQUE 1 t i �' � tr 1 './ � �oo� ;�� � - ' j E , : , rig; . 7 P.UB� i - r i ILLIK 01 Zs'-4-48 J .. � f . "r'" c. '' , , I ,, , 3 r1rR�:aa FI Bach 'Data Area�i; ' ' ..--71 - -, - ,--. y '.1.+'�RS1 ,Ct7LrT'u,TJ[d.�c ^, 17 �' ., 1 �. LS I h . ( ,, -, ,,',EuK #1 RY h C \ � w. t/ ' t �; ' s ,,,� � � BUSH FZe t , £ k '� J4 f 1. �` C � f �� Fig 4: Approximate mapped extent of poor quality 2D seismic data Chevron has an extensive grid of 2D spec data in addition to 9t proprietary 2D lines acqui ed in 2007 within the White Hills area and north bound through our working interest fields of Kuparuk and Pru•hoe Bay. There are no 3D seismic volumes which entirely cover the White Hills area. Currently, our key 2D li es through the White Hills prospective area have undergone several stages of reprocessing. In 2002, GeoT ace produced a pre - stack migration data set which was later reprocessed by Unocal in 2005 to attempt �• apply newer noise reduction techniques. However, after the merger with Chevron, and high grading of the W itea Hills prospective area, it was decided to try and increase the signal to noise ratio of the data further by app ing Chevron's 5 12/12/08 34 of 41 n ^ 1 Chevron UNOCAL Ca Alaska Resources proprietary noise attenuation technique. This was in effort to enhance the image in : large swath of low frequency, poor quality data (Fig 4). This poor data zone is coincident with a large p l rtion of the Chevron acreage on the Central North Slope. Consequently, Chevron decided to acquire 9 li es of (see below) of proprietary 2D seismic in 2007 to better resolve the stratigraphy, structure, identify pote tial shallow hazards, and aid in well placement. 2007 DATA ACQUISITION In the winter of 2007 (Jan 5 -Feb 11) nine 2D lines, approximately 170 sq miles as ou lined on Fig 5, were acquired over the White Hills area by CGGVeritas. The survey was designed to tie the urrent proposed well locations in a North -West — South -East strike direction with two long North –South tie lines. Every attempt was made to avoid water bodies whenever possible due to the statics issues that ice Ia es induce on seismic data. The drilling program for the White Hills area was developed from both geologic and g- ophysical data sets. Regional, reprocessed, and the 2007 White Hills 2D were evaluated to assess the pot-ntial for any shallow hazards. However, in general, the 2D seismic data quality is not adequate in some of the proposed well locations to fully determine the potential for shallow hazards. r r ..4. _ imIrevi ..........—,..,....,:•. „....41.27.4.,,...t.., Fil., ,° %.L.'-' 'N.., flt ° - * ` . 4' �I E III oit, m za I i ,$ a ". ".aK v WArr • w..a..r � �: ., •, :�»w• - ..✓` ire. �r �' - . . '^'v'= - "4 x it ::, .„5,,t4 . l , .44 " ' ., ¢t 7';_ • ,,::: _ 4 4S it 4 Vr 014 "" j„ , 1,\-c, ,„...2,,,:s.; ._ '',, ..,,p, .. i 0 6 . , 7 7,i .I. .. '1.- ,,. _ A"'"- Fig 5: Chevron 2007 2D seismic acquisition lines; acquired by CGG Veritas 6 12/12/08 35 of 41 • • Chevron UNOCAL O 111•1 Alaska Resources POTENTIAL SHALLOW HAZARDS 151°O 00 J 50° 4- 149 1 ! 148 FREE GAS 3 mi .... E ' dONT a Tarn *�I . "4 Ilia I . tip .. ' ... r { p 3 ty,r e F 0 �� f �� yyd, c m atk Atiii r limi '4" i �`. i 1 i . p ,-a * " � " f a � •, :. • .r # � " -, n '� T i t *�, e � - 4. mulair 1 ; vvr . .■;14 ,k . - f ' , - 4111- 1 -iirkoor .444 i iihi , y l Q , � ' ` `$, „ i ; ' ' Accu n 2 i' —"1-7-::"'13."4"itil,;:c) `'.° . - A N ' ►IRAT �y c► ,if A � . . ., . White Hills �. , � „ .._ _ _ 400r , A . ii � _• Area Fig 6: Alaska North Slope Gas Hydrate Energy Resources, USGS Open File Report 2004 -1454; by Timothy Collett Permafrost is expected at approximately 1200 feet measured depth below the surface, a d thickens northward. There is the possibility that gas hydrates could be present although not expected. The current known accumulations of gas hydrates (Fig 6) do no appear to be present in the White Hills prosp-ctive area. The 2D pre -stack time migration line, tying the Cirque wells (Fig 7a, b), shows a high am +litude reflector at the base of permafrost and bounded by faults. We suspect that this well blow out is possibly • ue to shallow gas. 7 12/12/08 36 of 41 00 ' r* WI/ - * :t >",t''' ' ‘I) Fi # w f :, ` `��r�kr } ��' 7:6: i � 1,1 41' ++fP` I. 4.#4 y itt i.t` r ?r• M } L � °Sl l v fi: t s. ^'g'` � err { t r F� y P [ � i '. • . Stiat , .7C• r;c -, ify;,,.1,„,46.447,,,i4 T 14 � YY'*. ..�' _ i f c 1 t ., , _ 4 I j.4. l { ..- $" °i i y'( (PJ��� . r �l � ' F I l :'f k q" a � 4 t 4,,,,,t,, c ., 0 4,,,, i ? , . , ., / - i ) , t .1,:. ti 7 �V # � 1, R ) f i 4 # • . l #+ I. R } R e. . iotto. 1 i ) ' ' ' ' ' , • .,.:atil, .,,,,7t...414,,r .,„ guff.- ,../44,,,"*" ./,,...! '''' —**, ,' ti it ' Li/ { x "� r � q s �1 J ( t °mo t . t } ��`ff >L 3i.. "''#'i ` 'R 3.} fpM / e ° *'� t = a .� �: �' , . 5 ..(4, I ji - — cr il ,..T.j. 4,1 I ° � � r d ,� / � . o f � � . ' } � ��1 _ (, � � : fi � �'ra =. ,a f it R :1 ` 7 . . 5 . y r {� ' c } 1 ! l � 14 s Et a 1 ' .-..t1 f , ,„1,.. . 1 - .. i ., 4 ' ' ' e,),\ L L a' i , .fi, Li Cc' 0 fl Q a .� 7 v,•. � �. �. _: "'#�d x* �, � � p � f Su � � �� B i � € O � 1 1 } 1 � , � a � . as '. � s .. .,,, — i ./:„ .4.4.-‘,"" , , ,-6.11‘11,i 1 ‘ z-,.; 1: : 8 '''-' ' 4' ',i,,V , ' . 6' - ii,,,,ki., .'I.*.',s,:,'-47,4*iI34xo-o",,t.=.e -',./..f....?;,..,/ r tit .2) y Chevron UNOCAL b Alaska Resources 1 The Wolfbutton 25 -6 -9 state is the most proximal checkshot to the proposed Stegod0'n 24 -6 -8 well. We expect similar velocities as shown in (Fig 9) on the Interval Velocity (Vint) vs Depth plot; Interval Transit Time (ITT) vs Depth. The plots show, as expected, faster velocities through permafrost and slo er velocities through the zone of interest below the base of permafrost. From the velocity analysis, we expect a normally pressured regime through the Prince Creek, Ugnu, West Sak formations, and Colville zone. ?. 1 Time -Depth 9- 0reckshots 8 Picks 11.aleckshats l 12 -Om , ND: 011 1 ....._w:. ,.. ... , <.DT:rt:vl» i Qik: Viet Picks QM: I1T thk: Time (2 Way Travel) w , pi [ 941 usltt Ws 124 picks usllt sec lime Feet 200 180 160 140 120 100 BO 60 40 20 ° 10000 15000 20000 100 9 displayed 40 60 80 100 120 140 0.0 0.5 1.0 1.5 2.0 2.5 3A � 0 j � .„,....5 50 ...... ..... __�__ Base _ ........ __ " —__. _.. ... s .......... ._.__.._.___..___ ......._. 0 600 50 800 -,-- Permafros 100 1000 ' '�, �� ' ., + Top (Mace Ck A 150 1200 . � Base P110c0 Ck A 200 1400 ' I.. ,.._. .=.- ws.�.i.. 250 1600 z1 .. ■ 1 UONU 300 1800 ( i 350 2000 400 2200 ': - �� ... .. Schrader Bluff A .. - - ... 450 2400 500 2600 2 550 2000 •l 600 3000 . r I Schrader Bluff El .. ....... ... .. t .... .... 650 3200 3400 - Scl ratler Blufff C Mark 700 ... Co1v810 Sm1tl Equiv er � .... 3600 Schrader Bluff C 750 a i 3600 BBD 4000 _ - - - -- 050 a200 900 4400 ' 4 7:,.. ( 950 4600 ■ t 1000 4800 1050 5000 I 5200 1100 5400 _. 1150 5600 1913:0N N N D:ON I D:ON Fig 9. Wolfbutton 32 -7 -8: Time vs Depth, Vint vs Depth, ITT vs Depth 10 12/12/08 39 of 41 w 0 • Chevron UNOCAL- 11110/ Alaska Resources MUD WEIGHT, SHALE RESISTIVITY, AND DOWNHOLE SAM PLER PRESSURE ANALYSIS e Key data in the vicinity of the proposed Stegodon 24 - - we ll include mudweight and resistivity of shale plots to indicate abnormal subsurface reservoir pressures, and downhol p sampler data from the Mastodon well. These wells were used in addition to the checkshot and VS da ta from the Wolfbut.on 32 well in order to • examine the possibility of pressure and velocity anomalies. Mud Wei ghts (MW) in ppg were plotted vs. depth for the Mastodon 6 -3 -9 well (Fig 10). The graphs indicate that drilling was balanced through our zone of • interest and there were no abnormally pressured reservoirs. During the 2088 drillinc season, we did not encounter any pressure anomalies. Mastodon Mastodon Q Mudweight ppg Ft-shale (o rn m 8.6 8.8 9 92 9.4 9.8 9. 140 1 4 1 0 s - _ 0 x . k S. .£ 8 4: �' w R ", a `4,17L", a V 44".44.1,4,„,'----;,,-,1),j-,? ', : , =. . ' . . : ,47 T I 1 400 � 0,--'4.'-- x ' '' f 1000 9 ,i.., „/ ,,,,-Lt--, 4,..4ione r 2000 2000 s =" '047.4 44, it-ts y n a 3000' ; *4 r ,tr 3400 o m ' v� � r 0 $ 4 i S 7? ' p 4000 4000 > �n+ 'T i t „ ' g /a n y' r Y A-44,44;1' Fig 10. Mudweight and Y a d y F, ; , 4 Shal Resistivity versus ▪ - # h (, Mea s u red Depth plot for ' 4� 1 the M astodon 6 -3 -9 well. 6000 6000 ` n d Y " "r 9 -5 8" casing was run to 1872 11 12/12/08 40 of 41 4 +1 • Chevron UNOCAL. b ONO Alaska Resources White Hills Field Mastadon Well Pressure - All Points 2150.000 - 2650.000 — Pressure gradient shift below the Schrader Bluff A Sand 3150.000 - 2 Slope 1: 0.4515 psi /ft Slope 2: 0.4773 psi/ft 3650.000 4150.000 4650.000 600.000 800.000 1000.000 1200.000 1400.000 1600.000 1800.000 Pressure, psi —40—Pressure Profile Figure 11. Reservoir pressure trends from down -hole sampler log (RCI log), indicating normally pressured reservoirs to the proposed total depth. SUMMARY In conclusion, there is one coherent high amplitude event near the base of permafrost (9W ft TVDSS) evident on 2D seismic lines. That high amplitude event may represent shallow gas. Extra caution ishould be taken when drilling just below the base of permafrost here. Prepared by: Dave Buthman Qiang Sun Geologist / Technical Team Lead Exploration Geophysicist Alaska New Ventures Team Alaska New Ventures Team MidContinent / Alaska BU MidContinent / Alaska BU (281) 561 -3401 (281) 561 -4958 buthbdb(@,chevron.com a nsutaa..chevron.com 12 12/12/08 41 of 41 • TRANSMITTAL LETTER CHECKLIST WELL NAME .S .1e J ft. Z4`' - - PTD# 2.4)8 - Zo 7 Development Service / Exploratory Stratigraphic Test Non - Conventional Well FIELD: POOL: Circle Appropriate Letter / Paragraphs to be Included in Transmittal Letter CHECK ADD -ONS WHAT (OPTIONS) TEXT FOR APPROVAL LETTER APPLIES MULTI LATERAL The permit is for a new wellbore segment of existing well (If last two digits in Permit No. , API No. 50- - - API number are between 60 -69) Production should continue to be reported as a function of the original API number stated above. PILOT HOLE In accordance with 20 AAC 25.005(0, all records, data and logs acquired for the pilot hole must be clearly differentiated in both well name ( PH) and API number (50- - - ) from records, data and logs acquired for well SPACING The permit is approved subject to full compliance with 20 AAC EXCEPTION 25.055. Approval to perforate and produce / inject is contingent upon issuance of a conservation order approving a spacing exception. assumes the liability of any protest to the spacing exception that may occur. DRY DITCH All dry ditch sample sets submitted to the Commission must be in SAMPLE no greater than 30' sample intervals from below the permafrost or from where samples are first caught and 10' sample intervals through target zones. Non - Conventional Please note the following special condition of this permit: Well production or production testing of coal bed methane is not allowed for (name of well) until after (Company Name) has designed and implemented a water well testing program to provide baseline data on water quality and quantity. (Company Name) must contact the Commission to obtain advance approval of such water well testing program. Rev: 1/11/2008 s ' , -, f ) Field & Pool Well Name: STEGODON 24-6 -8 Program EXP Well bore seg ❑ PTD#: 2082070 Company UNION OIL CO OF CALIFORNIA Initial Class/Type EXP / PEND GeoArea 890 Unit On /Off Shore On Annular Disposal ❑ Administration 1 Permit fee attached NA 2 Lease number appropriate Yes 13 Unique well name and number Yes 4 Well located in a definedpool No Exploratory well 5 Well located proper distance from drilling unitboundary Yes 6 Well located proper distance from other wells Yes Nearest well is 3 -1/2 miles to ESE (Panthera 28 -6 -9) 7 Sufficient acreage_ available in drilling unit Yes 8 If_deviated, is wellbore plat_incJuded NA Vertical well 9 Operator only affected party Yes Lease is 70% Unoca 30% Total E &P 10 Operator has appropriate bond in force Yes 11 Permit can be issued without conservation order Yes Appr Date 12 Permit can be issued without administrative approval Yes 13 Can permit be approved before 15 -day wait Yes SFD 1/212009 14 Well located within area and strata authorized by Injection Order # (put IO # in comments) (For NA 15 All wells within 1/4 mile area of review identified (For service well only) NA • 16 Pre- produced injector: duration of pre production less than 3 months (For service well only) NA 17 Nonconven, gas_conforms to AS31.05.030(y1.A),((2.A -D) NA 18 Conductor string provided Yes Engineering 19 Su face_casing protects all_known USDWs NA No subsurface water sources in area. Surface casing -500' below permafrost, 20 CMT vol adequate to circulate on conducto & surf csg Yes 21 GMT vol adequate to tie -in long string to surf csg Yes 22 CMT will cover all known productive horizons Yes 23 Casing designs adequate for C, T, B & permafrost Yes '24 Adequate tankage_or reserve pit Yes Rig equipped with steel pits. No reserve pit planned. All waste to approved disp osal well(s). 25 If are- drill, has a 10403 for abandonment been approved NA 26 Adequate wellbore separation_proposed Yes Nearest well -3 -1/2 miles distant. 27 If_diverter required, does it meet regulations Yes 12- 1 /4 " hole _planned. Rig equipped with 12" diverter_line. Ths has been approved previously. Appr Date 28 Drilling fluid program schematic_& equip list adequate Yes ,Maximum expected formation pressure 8.4 EMW. MW planned up to 9.5 ppg or as need ed. TEM 1/5/2009 29 BOPs,do they meet regulation Yes 30 BOPI= _press rating appropriate; test to (put psig in comments) Yes MASP calculated at 969 psi. 2500 psi BOP test planned. 31 Choke manifold co mplies w /API RP -53 (May 84) Yes fr 32 Work will occur without operation shutdown Yes • 33 Is presence of H2S gas probable No H2S has not been reported in the offsetwells. _ Mud shold preclude H2S on rig. Rig has sensors and alar ms. 34 Mechanical condition of wells within AOR verified (For service well only) NA , 35 Permit can be issued w/o hydrogen sulfide measures No Remote exploratory well,will be mudiogged; mud scavengers will _boon location. Geology 36 Data_presented on potential overpressure zones YeS Normal pressure gradient expected; will be drilled with 9.0 to 9.5 ppg mud. Appr Date 37 Seismic_analysis of shallow gas zones Yes Seismic maplitude indicates shallow gas may be present near the base of p ermafrost. SFD 1/2/2009 38 _Seabed _condition survey(if off - shore) NA ,39 Contact name /phone for weekly_ progress reports [exploratory only] Yes Tim Brandenburg 907 - 263 -7657 Geologic Engineering Public Commissioner: Date: Commissioner: Date Co i - Date 6,4 - i -o, V / -6--a
