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Home My WebLink About2012 Northstar Oil PoolEs Katrina Cooper Head of Base Management, Alaska Strategic Performance Unit March 18, 2013 Cathy Foerster Commissioner Alaska Oil and Gas Conservation Commission 333 W. 7th Ave #100 Anchorage, Alaska, 99501-3539 BP Exploration (Alaska) Inc. 900 East Benson Boulevard P.0 Box 196612 Anchorage, Alaska 99519-6612 Main 907 564 5111 RE: Northstar Field, Northstar Oil Pool Annual Reservoir Performance Report Dear Ms. Foerster: BP Exploration (Alaska) Inc., as operator of the Northstar Unit, hereby submits the attached Annual Reservoir Performance Report in accordance with the requirements of Conservation Order 458A and 20 AAC 25.115. This report covers the period January 1, 2012 through December 31, 2012. The report is organized according to the outline provided in Rule 7 of the conservation order. Item f, Future development plans, and g, Review of Annual Plan of Operations and Development have been combined into a single item titled Review of Annual Plan of Operations and Development and Future Development plans. The final section addresses 20 AAC 25.115. BP reserves the right to alter the content of the analyses contained in this report at any time based upon the most recent surveillance information obtained. Please contact Eko Apolianto (564-4569) or Mark Sauve (564-4660) if there are any questions. Sincerely, Katrina Cooper WcaNLOa SLNINAGL Phone:(907) 564-4212 CO BCHyIF or, KATRINA nVVPE,Z Fax: (907) 564-4440 Email: Katrina.Cooper@bp.com Web: www by com cc: Mark Fesmire, BSEE Kevin Banks, DNR Bob Gage, Murphy R. L. Skillern, BP File Annual Reservoir Performance Report Northstar Field N'orthstar Oil Pool January 2012 through december 2012 by March, 2013 Table of Contents A. Progress of Enhanced Recovery Project and Reservoir Management Summary B. Voidage Balance by Month of Produced Fluids and Injected Fluids and Cumulative Status C. Summary and Analysis of reservoir pressure surveys within the pool D. Results and Analysis of Production and Injection Log surveys, tracer surveys, observation well surveys and any other special monitoring. E. Review of pool production allocation factors and issues over the prior year F. Review of Annual Plan of Operations and Development and Future Development Plans G. Status of wells shut-in for 365 days or more Attachment 1: Map of Well Locations Attachment 2: Northstar Field 2012 Overview Statistical Summary Attachment 3: Northstar Field 2012 Reservoir Pressure Report, Form 10-412 2 A) Progress of Enhanced Recovery Project and Reservoir Management Summary During 2012, no new wells were drilled or sidetracked in the Northstar Unit. The location of all the wells in the Northstar Unit is shown in Attachment 1. Production and injection statistics are summarized in Attachment 2. Average daily oil production from the Northstar field was 8,280 bopd and average daily gas injection was 359.4 mmscfpd. The reservoir voidage balance values reported do not include oil production from satellite well NS34A or Kuparuk zone production from well NS08. During 2012, gas injection was calculated to be 2,773 thousand -reservoir barrels (MRB) more than reservoir voidage. At year end, the reservoir overall cumulative voidage replacement ratio was 1.019. The average of reservoir pressure control for 2012 was 5,104 psia. 3 B) Voidage Balance by Month of Produced Fluid and Injected Fluids - 2012 2012 4 net infection (Injection - Production) Produced Fluids Cum Net Year Injected Fluids Injection, Cum, start-up, MRB MRB MRS. Cum 278 18,303 118 Cum 18,421 280 677 18,702 Total since Formation Import Total Year since 238 1,629 Free Gas, Water, Voidage, Year start-up, Gas, Gas, Injection, Cum, start-up, Month Oil, MRB MRB MRB MRB Cum, MRB MRB MRB MRB MRB MRB MRB Jan -2012 724 8,833 419 9,556 9,556 1,040.373 9,297 538 9,835 9,835 1,058,677 Feb -2012 536 6,955 370 7,491 17,048 1,047.865 7,213 396 7,609 17,444 1,066,286 Mar -2012 513 6,863 365 7,376 24,424 1,055,241 7,138 518 7,656 25,101 1,073,942 Apr -2012 442 6,149 342 6,591 31,014 1,061,831 6,378 541 6,920 32,020 1,080,862 May -2012 466 6,826 336 7,292 38,306 1,069,123 7,067 610 7,677 39,697 1,088,539 Jun -2012 435 6,846 334 7,281 45,588 1,076.404 7,084 435 7,519 47,217 1,096,058 Jul -2012 465 7,546 368 8,011 53,598 1,084,415 7,791 462 8,253 55,469 1,104,311 Aug -2012 312 4,994 260 5,306 58,904 1,089,721 5,149 358 5,508 60,977 1,109,819 Sep -2012 319 4,980 247 5,299 64,203 1,095,019 5,147 334 5,481 66,458 1,115,300 Oct -2012 468 7,469 341 7,937 72,140 1,102, 957 7,713 416 8,130 74,588 1,123,429 Nov -2012 396 5,923 321 6,318 78,459 1,109, 275 6,120 345 6,465 81,053 1,129, 894 Dec -2012 425 7.022 349 7,446 85,905 1,116, 722 7,239 386 7,625 88,677 1,137, 519 2012 Totals 5,500 80,405 4,053 85,905 83,336 5,342 88,677 4 net infection (Injection - Production) Cum Net Year since. Injection, Cum, start-up, MRB MRB MRS. 278 278 18,303 118 396 18,421 280 677 18,702 329 1,006 19,031 385 1,391 19,416 238 1,629 19,654 242 1,871 19,896 202 2,073 20,098 182 2,255 20,280 192 2,447 20,472 147 2,594 20,619 178 2,773 20,798 2,773 C) Summary and Analysis of reservoir pressure surveys within the pool Static bottom hole pressures collected in 2012 are summarized below. Well Extroplated Pressure at -11,100' Date Datum, psia TVDss Data Source NS06 5/18/12 5089 SBHP NS08 3/1/12 4266* Other NS08 4/21/12 4253* Other NS08 6/30/12 4259* Other NS08 7/8/12 4270* Other NS08 9/9/12 4264* Other NS09 4/17/12 5096 SBHP NS13 4/17/12 5108 SBHP NS14A 4/16/12 5116 SBHP NS18 4/15/12 5101 SBHP NS19 5/17/12 5064 SBHP NS21 5/25/12 5103 SBHP NS24 4/14/12 5117 SBHP NS28 3/23/12 5143 Other NS28 6/30/12 5129 Other NS28 9/30/12 5153 Other NS28 12/31/12 5144 Other NS33A 2/28/12 5096 SBHP NS34A 5/26/121 4996 SBHP * Datum for Kuparuk reservoir is 9000' TVDSS These pressures are graphically represented in the next figure that is a plot of Ivishak pressure by well versus time. These data show a slight decrease of reservoir pressures during 2012. The average Northstar field reservoir pressure for 2012 is 5,104 psia, down some 5 psi from the 2011 average. Please note that well NS -34A is a satellite well to the main field and the reservoir pressures reported from NS08 during 2012 are from the Kuparuk Reservoir. A complete listing of data from these surveys is shown in Attachment 3 on the AOGCC Reservoir Pressure Report form. 5 L; LO CV I � T R MMN O z z z M N � z z z N_ m ) (l r � I 0 LO z z !z f T CD rn z z z mCD U) (n U) z z z O n N U) fn N z z z �L�er L-po L1nr L -AV L-uer L-po Linr L jdV L-uer L-po L-Inr L -AV L-uer -Po 1nr -jdV -uer -PO 1nr -idV mer -PO 1nr -jdV -uer -PO -Inr -jdV -uer -PO 1nr AV -uler -PO 1nr AV -uer -:Po -Inr -jdV -Uer -Po 1nr AV -uer -Po 1nr AV -uer LO O LO O O LO LO LO LO LO LO VISd `(0A1.00 L `L L wn;ea ;e) ajnssaJd JIOAJOSO j Kel �� 1�I♦� mm 1 -AM Wy�il_ !P �p�MWAWMA ; t►,�r�r !� I r w� _ LO O LO O O LO LO LO LO LO LO VISd `(0A1.00 L `L L wn;ea ;e) ajnssaJd JIOAJOSO j Kel D) Results and Analysis of Production and Injection log surveys, tracer surveys, observation well surveys and any other special monitoring. No new production/injection profiles were obtained in 2012. The following table summarized these as well as previous profile results. ' Did not log across entire perforation interval; therfore, unknown contibutions from open zones below logged interval are indicated by -. Gas tracer status: The gas tracer program, initiated in 2004, was concluded in 2008 and no further updates are required for this reporting period. 7 Percents a of flow from/to interval. Blank intervals are not rforated. Well Name Well Type Date Log Type Ivishak Shublik D Zone E Ivishak Zone D Ivishak Zone C3 Ivishak Zone C2 Ivishak Zone C1 Ivishak Zone B NS23 Injector 7/13/2003 Memory SIT1P 6 29 13 18 16 18 NS27 In ector 7/21/2004 S!T/P 5 12 19 26 38 NS13 Producer 10/4/2004 S!f/P/Gradio/Ghost 12 59 19 10 NS08 Producer 12/7/2004 S/T/P/Gradin/Ghost/DEFT 55 31 9 5 NS 09 1 Producer 12/11/2004 S/T/P/Gradio 54 29 17 0 NS24 I Producer 3/26/2005 Memory SITIP/Gradio 43 57 0 NS24 Producer 312712005 RST/Borax-!PNL NS14 Producer 3/29/2005 S!r/P/Gradio/Ghost 55 43 2 NS19 Producer 5/16/2005 Memory s/T/P 100 NS14 Producer 6/26/2005 Memo S/T/P/FCAP 17 45 38 NS06 Producer 6/30/2005 SIT/PlGradWGhost 49 40 11 NS28 Producer 8/20/2005 1 Memo S/T/P/D EFT/G host 100 NS05 Producer 10/7/2005 Memo S/T/P 60 40 0 NS16 Producer 5/5/2006 S/T/P/Gradio/Ghost 43 42 15 NS11 Producer 12/20/2006 Memo S/T/P/D EFT/G host 82 18 NS09 Producer 12122/2006 S/T/P/Gradio 65 30 5 NS08 Producer 4/10/2007 Memo S/T/P 20 0 27 53 NS24 Producer 4/11/2007 Memo S/T/P 50 50 NS19 Producer 4/24/2007 S/T/P/Gradio/GhosttDEFT 98 2 NS13" Producer 7/14/2007 Memory SIrIP/Gradio 0 100 NS15' Producer 5/10/2008 Memory S/TArradlo 87 13 NS09 Producer 8/29/2008 Baker GaslFluid View NS24 Producer 8/30/2006 Baker Gas/Fluid View NS16A Producer 9/12/2008 S/T/P/Gred io/Ghost/DEFT 100 0 NS16A Producer 9/16/2008 S/T/P/Gradio/Ghost/DEFT 100 0 NS16A I Producer 10/21/2008 SIT1PIGradlolGhosVDEFT 100 0 NS24 Producer 12/3/2008 S/T/P/GradiolGhost 100 0 NS24 Producer 12/5/2008 STr/P/Gradio/Ghost 0 1 100 0 NS16A Producer 2/1212009 S/T/P/Gradio/Ghost/DEFT 100 0 NS05 Producer 2/14/2009 S/T/P/Gradio/Ghost/DEFT 73 27 NS19 Producer 4/19/2009 SIT/P/Gradio/GhosVDEFT 96 4 NS16A Producer 4/20/2009 SIT/P/Gradio1GhosVDEFT 90 10 NS33A Producer 11/12/2009 Neutron WF Jon and Memory STOP 100 NS05 Producer 11/16/2009 Memo S/T/P/Gradio/GhosVDEFT 70 30 NS30 Producer 11/19/2009 Memo S/T/P/GradiolGhosVDEFT 50 50 NS11 Producer 11/21/2009 Memo SIT/P/Gradio/DEFT 80 20 NS21 Producer 12/13/2009 Memo S/T/P/GradiolGhort/DEFT 100 NS20 Producer 12/15/2009 Memo S!T/P/Gradio/GhosVDEFT 50 50 NS22 Producer 12116/2009 Memo S/T/P/GradioJGhoaVDEFT 60 40 NS34A Producer 12/21/2009 Memo S/T/P/GradiolGhosVDEFT 100 NS16 Producer 5/4/2010 S/T/P/GradiolGhosVDEFT 65 30 5 N506 Producer10119120101 S/T/P/Gradio/Ghost/DEFT 1 p 1 70 30 ' Did not log across entire perforation interval; therfore, unknown contibutions from open zones below logged interval are indicated by -. Gas tracer status: The gas tracer program, initiated in 2004, was concluded in 2008 and no further updates are required for this reporting period. 7 E) Review of pool production allocation factors and issues over the prior year Theoretical production is calculated for each Northstar producing well on a daily basis. A well's theoretical production is calculated using average wellhead flowing pressure and hours on production as follows: n hours produced Pwhf _ X 1 — X Qaof — aheoretical 24 Pwhsi Where: hoursproduced ==hours on line Pwhf = average wellhead flowing pressure Pwhs; = shut-in wellhead pressure n = flow exponent Qaof = absolute open flow of well with Pwhf = 0 psi Qtheoretical = theoretical production The input parameters (n, Qaof and Pwhs;) for each well are determined from well test data and systems analysis and are reviewed each time new test data becomes available. The actual total production for a day is divided by the summation of the theoretical production from each well to calculate a daily allocation factor. This allocation factor is then multiplied by each well's theoretical production to calculate allocated production. Northstar field allocation factors for 2012 averaged 1.18 for oil, 1.16 for water and 0.98 for gas. E-3 F) Review of Annual Plan of Operations and Development and Future Development Plans Northstar concluded 2012 with six gas injection wells, twenty-one producing wells and two Class I disposal wells available for utilization. Historical well count for the last two ears are summarized in the following table_ • Year • Wells Year Count Producers Injectors Class I Disposal 1 NS05 NS17 NS10 2 NS06 NS23 NS32 3 NS07 NS25 4 NS08 NS27 5 NS09 NS29 6 NS11 NS31 7 NS12 8 NS13 9 NS14A 10 NS15 11 NS16 N 12 NS18 13 NS19 14 NS20 15 NS21 16 NS22 17 NS24 18 NS28 19 NS30 20 NS33A 21 NS34A 1 NS05 NS17 NS10 2 NS06 NS23 NS32 3 NS07 NS25 4 NS08 NS27 5 NS09 NS29 6 NS11 NS31 7 NS12 8 NS13 9 NS14A N 10 NS15 O 11 NS16 N 12 NS18 13 NS19 14 NS20 15 NS21 16 NS22 17 NS24 18 NS28 19 NS30 20 NS33A 21 NS34A BSEE wells in bold 0 Future Development Plans The possibility that satellite hydrocarbon accumulations may exist within expected drilling reach from the island is recognized. These and locations within the main Northstar Ivishak formation will be the subject of additional future appraisal. As of March 2013 no drilling activities are ongoing at Northstar. The Nabors 33 drilling rig was de -mobilized from Northstar Island during the 2010 summer barging season. 10 G) Status of Wells Shut-in for 365 days or More (20 AAC 25.115) Producers NS09, NS15, NS22, NS24, NS28 and NS33A were the only wells at Northstar shut-in for all of 2012. Northstar Shut-in Wells 2012 1 Reasons for Well Shut -In A. High GOR, curently uncompetitive to produce due to facility constraints, no known mechanical problems B. High water, currently uneconomic to produce, no known mechanical problems C. Low production rate, no known mechanical problems D. Mechanical Problem E. Other (Specify under comments) 2. Current Mechanical Condition Briefly describe the current mechanical condition including the condition of installed tubing and casing strings. 3. Future Utility 1. Evaluating remedial, sidetrack and/or redrill opportunities 2 Remedial well work planned 3, Long term Shut-in we1V No immediate plans 4 Suspended well 5. P&A planned 6 Other (Specify under comments) 11 Date Shut- Reason for Well Current Mechanical Condition of Future Utility Plans & SwName In Shut -In' Wahl Possibilities' Comments NS09 Dec -11 A High GOR - Operable - no known problems 2. Remedial well work Evaluating gas shut-off options. Uncom Detetive planned NS15 Mar -09 D. Mechanical Secured with down hole mechanical 3. Long term Shut-in/No Problem plug and BPV immediate plans NS22 Jun -10 D. Mechanical Secured with down hole mechanical 3. Long term Shut-in/No Problem dup and BPV immediate clans NS24 May -11 A High GOR - Operable - no known problems 3. Long term Shut-in/No Uncompetetive immediate plans NS28 Jan -10 A High GOR - Operable - no known problems 6. Other (Evaluating injection conversion potential Uncom tetive NS33A Feb -11 D. Mechanical Non-operable. Well shut-in awaiting 2. Remedial well work Problem wellwork Dlanned 1 Reasons for Well Shut -In A. High GOR, curently uncompetitive to produce due to facility constraints, no known mechanical problems B. High water, currently uneconomic to produce, no known mechanical problems C. Low production rate, no known mechanical problems D. Mechanical Problem E. Other (Specify under comments) 2. Current Mechanical Condition Briefly describe the current mechanical condition including the condition of installed tubing and casing strings. 3. Future Utility 1. Evaluating remedial, sidetrack and/or redrill opportunities 2 Remedial well work planned 3, Long term Shut-in we1V No immediate plans 4 Suspended well 5. P&A planned 6 Other (Specify under comments) 11 N Projection Information_ Alaska Slate Plane Zone 4 Clarke 1866, NAD 1927 Attachment 2: NORTHSTAR FIELD 2012 OVERVIEW STATISTICAL SUMMARY WELL STATISTICS As of 12131/2012 Full year (1) As of Dec -12 (2) Producers 15 11 Injectors 8 5 NOTES: (1) Well count data reflects ONLY those wells which contributed to production injection during the respective year (2) Active wells as of Decerrber 2012 PRODUCTION/INJECTION STATISTICS Cumulative Start - Up through Production 2012 12/31/12 Oil (1313L) 3,030,462 156,230,663 Gas (MCF) 131,832,953 1,496,965,795 Water (BBL) 4,901,354 44,871,200 Injection Water (BBL) into NS10 & NS32 Disposal Well 5,112,233 49,010,867 Gas (MCF) 131,555,304 1,676,780,209 Balance (excludes satellite well NS -34A and NS08 Kup oil Production Cum Production (MRB) 86,002 1,116,812 Cum Injection (MRB) 88,677 1,137,513 Over/Under (MRB) 2,676 20,702 DAILY AVERAGE RATE DATA 2012 Production Oil, BOPD 8,280 Gas, MCF/D 360,199 Water, BWPD 13,392 Injection Water, BWPD 13,968 Gas, MCFPD 359,441 AVERAGE RESERVOIR PRESSURE Average of surveys obtained in 2012 5104 psia 13 Attachment 3: Reservoir Pressure Report 14 STATE OF ALASKA ALASKA OIL AND GAS CONSERVATION COMMISSION RESERVOIR PRESSURE REPORT I. Operator: BP Exploration/Alaska Inc. 2 Address: I P.O. Box 196612. Anchorage. Alaska 99519.6612 3. Unit or Lease Nana: Alorthstar thrift 4 Field and Pool: 5. Datum Reference: Northstar ReldlNorthstar Oil Pool -11.100 6.01 Gravity: 7. Gas Gravity: 42 0.79 5. Vnkll Haan and Nunber: 9. AA Number 10. Type 50XXXXXXXXX)O(X See NOD.4SFES Instructions 11. AOGCC 12 Zane Pool Oode 13. Pertorated 14. Final Test Intervals Date Top - Bottom TVDSS 15. Shut-in 15. Press. Time, Hours Surv. Type (see instructions for codes) 17. B.H. 16. Depth Tenp. Tool TVDSS 19. Final Observed Pressure at Tool Depth 20 Datum 21. Pressure 22. Pressure at TVDSS (input) Gradient, psilft Datum(car)psig INS33A 50029233250100 0 590100 Nishak :25778-2583 2/28/12 9335 SBHP 250 11000 5068 11100 0 275 5096 INS08 50029230660000 0 5901 Ool Ku aruk +9924-6961 3/1/12 53 .Other 191 8834 4180 9000 0.26 4266 INS28 50029232480000 O 590100 Mshak 1052-1109 111052-11091" 3/23/12 6648 Other 242 10480 5001 11100 0.124 5143 INS24 50029223111000 0 590100 Mshak 10965-1104 4/14/12 8880 SBHP 251 11000 5106 11100 0.110 5117 INS18 50029223102000 0 590100 Mshak 10977-1104 4/15/121 1656 SBHP 252 11000 5091 11100 0.103 5101 INS14A 50029223026010 O 590100 Mshak 11091-1108 4/16/12 1998 SBHP 253 11000 5105 11100 0.109 5116 NS09 50029223052000 0 1 590100 Mshak 10930.1109 4/17/12 2904 SBHP 251 11000 5085 11100 0.1081 5096 NS13 50029223017000 0 590100 Mshak 10924-1109 4/17/12 2016 SBHP 253 110001 5098 11100 0.103 5108 NS08 50029230680000 0 590100 Kuparuk 19924-8961 4/21/12 36 Other 197 8634 4167 90M 0 26 4253 NS19 50029223102000 0 590100 Mshak 10953. I 103C 51171121 57 SBHP 253 11000 5054 11100 0 103 5064 NS06 50029223088000 0 590100 Ivishak 10900-1109 5/18/12 912 SBHP 252 11000 5078 11100 0.108 5089 NS21 50029223126000 0 590100 Ivishak 10996-1111 5/25/12 180 SBHP 249 11000 5092 111001 0.108 5103 N834A 50029223301010 0 590100 Ivishak 11049-11091 5/26/12 58 SBHP 252 49% 11100 0.426 4996 NS08 50029230680000 0 590100 Ku aruk 6924-8961 6/30/12 180 -Other 197 4173 9000 0 26 4259 NS28 50029232480000 O 590100 Mshak 11052-1109. 6/30/12 12912 Other 242 110480 4987 11100 0124 5129 NS08 50029230680000 0 590100 Kuparuk 8924-8961 718112 370 Other 197 4184 9000 0264270 NS08 50029230680000 O 590100 Ku aruk 8924-8961 9/9/12 439 Other 197 4178 9000 0 26 4264 NS28 50029232480000 0 590100 Mshak 11052-1109 9/30/12 15072 Other 242 10480 5011 11100 0.124 5153 NS28 50029232480000 0 5901001 Mshak 11052-1109 12/31/12 15072 Other 242 10480 5002 11100 0.124 5144 Comments: Surveys Indicated as "Other' w ere obtained from Cidra guages 23. Alitests reported herein were Trade in accordance w I hereby certify that the foregoing is true and t ine Signature Printed Name the applicable rules, e0guia and instructions est know Wrk Seuve of the Alaska 09 and Cas Conservation Commission. Title Dale Northstar Lead Production Engineer Wren 12, 2013 14