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2008 Northstar Oil Pool
Annual Reservoir Performance Report Northstar Field Northstar Oil Pool January 2008 through December 2008 March, 2008 2 Table of Contents A. Progress of Enhanced Recovery Project B. Voidage Balance by Month of Produced Fluid and Injected Fluids 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 2008 Overview Statistical Summary Attachment 3: Northstar Field 2008 Reservoir Pressure Report, Form 10-412 3 A) Progress of Enhanced Recovery Project During 2008, well NS-16 was sidetracked and completed in the Ivishak reservoir (as NS16A) with initial production at 3,000 bbls/day. Also during 2008, well NS- 34A was drilled and completed in the Ivishak reservoir in a satellite structure adjacent to the main field. Well NS-34A’s produced fluids are not included in the main field’s balance calculation in Section B. Well NS-34A’s 2008 production was Oil=1,149,819 Bbls, Gas=2,087,703 MScf, and Water=155,547 Bbls. The location of these wells is shown in Attachment 1. Production and injection statistics are summarized in Attachment 2. Average oil production was 31,258 bopd and average gas injection was 507.6 mmscfpd. The balance values reported do not include oil production from satellite well NS-34A During 2008, gas injection was calculated to be 272 thousand-reservoir barrels (MRB) more than reservoir voidage. At year end, the reservoir overall cumulative voidage replacement ratio is 1.00. The average of reservoir pressure control for 2008 was 5097. 4B) Voidage Balance by Month of Produced Fluid and Injected Fluids – 2008 2008 MonthOil, MRBFree Gas, MRBWater, MRBTotal Voidage, MRBYearCum, MRBCum since start-up, MRBFormation Gas, MRBImport Gas, MRBTotal Injection, MRBYearCum, MRBCum since start-up, MRBNet Injection, MRBYearCum, MRBCum since start-up, MRBJan-2008 2,327 7,783 476 10,110 10,110 551,258 9,318 783 10,100 10,100 551,213 -10 -10 -44Feb-2008 2,172 7,699 440 9,870 19,981 561,128 9,136 740 9,875 19,976 561,089 5 -5 -39Mar-2008 2,205 8,534 445 10,739 30,720 571,867 9,990 796 10,787 30,762 571,875 48 43 8Apr-2008 1,932 7,194 401 9,126 39,846 580,993 8,468 655 9,123 39,885 580,998 -3 40 5May-2008 1,743 6,253 375 7,996 47,842 588,989 7,392 725 8,117 48,002 589,115 121 161 126Jun-2008 1,883 8,870 419 10,752 58,594 599,742 10,110 503 10,613 58,615 599,728 -140 21 -14Jul-2008 1,899 9,220 457 11,118 69,712 610,860 10,475 636 11,111 69,726 610,839 -7 14 -21Aug-2008 1,772 9,057 437 10,829 80,541 621,689 10,229 633 10,862 80,588 621,701 33 47 13Sep-2008 1,839 9,360 454 11,199 91,740 632,888 10,575 633 11,208 91,796 632,909 9 56 21Oct-2008 1,715 8,741 429 10,456 102,196 643,343 9,872 650 10,522 102,318 643,431 66 122 87Nov-2008 1,812 10,228 448 12,041 114,236 655,384 11,429 603 12,031 114,349 655,462 -10 113 78Dec-2008 1,756 10,018 451 11,775 126,011 667,159 11,180 754 11,934 126,283 667,396 159 272 2372008 Totals 23,055 102,956 5,232 126,011 118,173 8,110 126,283 272Produced Fluids Injected FluidsNet Injection (Injection - Production) 5 C) Summary and Analysis of reservoir pressure surveys within the pool Static bottom hole pressures collected in 2008 are summarized below. Well Date Extrapolated Pressure at -11,100' TVDss Datum, psia Data Source NS05 05/05/2008 00:00 5075 SBHP NS08 01/13/2008 14:42 5130 Cidra NS08 02/14/2008 15:08 5134 Cidra NS08 04/28/2008 05:16 5133 Cidra NS08 05/27/2008 09:02 5136 Cidra NS08 06/16/2008 08:26 5133 Cidra NS08 06/28/2008 00:00 5127 Cidra NS08 07/09/2008 00:00 5126 Cidra NS08 08/17/2008 00:00 5121 Cidra NS08 09/11/2008 00:00 5124 Cidra NS08 09/27/2008 00:00 5124 Cidra NS08 10/14/2008 00:00 5122 Cidra NS09 05/24/2008 19:35 5070 SBHP NS09 12/17/2008 00:00 5051 SBHP NS13 04/24/2008 11:36 5071 Cidra NS13 05/11/2008 23:56 5071 Cidra NS13 07/26/2008 00:00 5063 Cidra NS13 08/17/2008 00:00 5063 Cidra NS13 09/05/2008 00:00 5062 Cidra NS13 10/10/2008 00:00 5100 Cidra NS13 11/02/2008 00:00 5096 Cidra NS13 12/27/2008 00:00 5095 Cidra NS14A 01/21/2008 02:20 5104 Cidra NS14A 02/09/2008 01:16 5103 Cidra NS14A 04/23/2008 00:00 5103 Cidra NS14A 05/11/2008 00:00 5101 Cidra NS14A 05/24/2008 06:32 5106 Cidra NS14A 06/16/2008 17:48 5105 Cidra NS14A 06/25/2008 00:00 5100 Cidra NS14A 07/14/2008 00:00 5098 Cidra NS14A 08/17/2008 00:00 5098 Cidra NS14A 09/22/2008 00:00 5094 Cidra NS14A 09/27/2008 00:00 5094 Cidra 6 NS14A 10/09/2008 00:00 5093 Cidra NS14A 10/22/2008 00:00 5093 Cidra NS14A 12/05/2008 00:00 5092 Cidra NS14A 12/31/2008 00:00 5089 Cidra NS15 04/21/2008 00:00 5108 SBHP NS16A 04/05/2008 00:00 5121 SBHP NS19 05/04/2008 00:00 5086 SBHP NS20 05/04/2008 00:00 5111 SBHP NS21 05/04/2008 20:20 5129 Cidra NS21 08/17/2008 00:00 5062 Cidra NS21 10/07/2008 00:00 5062 Cidra NS22 05/03/2008 00:00 5093 Cidra NS24 05/23/2008 00:00 5112 SBHP NS28 02/18/2008 00:52 5116 Cidra NS28 03/12/2008 00:02 5117 Cidra NS28 03/31/2008 16:40 5114 Cidra NS28 04/24/2008 00:00 5115 Cidra NS28 05/18/2008 00:00 5113 Cidra NS28 06/30/2008 00:00 5099 Cidra NS28 07/24/2008 00:00 5092 Cidra NS28 09/07/2008 00:00 5093 Cidra NS28 09/30/2008 00:00 5086 Cidra NS28 10/12/2008 00:00 5096 Cidra NS28 11/02/2008 00:00 5087 Cidra NS28 12/31/2008 00:00 5078 Cidra NS30 05/04/2008 19:34 5080 Cidra NS34A 04/20/2008 00:00 5116 RFT - Stethescope NS34A 12/16/2008 4930 SBHP NS34A 12/16/2008 4928 Cidra These pressures are graphically represented in the next figure that is a plot of pressure by well versus time. These data indicate pressures declined during 2008. As of March 2009, additional imported gas from the PBU is being injected into the reservoir to increase the reservoir pressure. A complete listing of data from these surveys is shown in Attachment 3 on the AOGCC Reservoir Pressure Report form. 7 Northstar Well Pressure Data 500050505100515052005250Oct-01Dec-01Feb-02Apr-02Jun-02Aug-02Oct-02Dec-02Feb-03Apr-03Jun-03Aug-03Oct-03Dec-03Feb-04Apr-04Jun-04Aug-04Oct-04Dec-04Feb-05Apr-05Jun-05Aug-05Oct-05Dec-05Feb-06Apr-06Jun-06Aug-06Oct-06Dec-06Feb-07Apr-07Jun-07Aug-07Sep-07Nov-07Jan-08Mar-08May-08Jul-08Sep-08Nov-08Reservoir Pressure (at Datum 11,100' TVD), PSIANS06NS07NS08NS09NS12NS13NS14NS15NS16NS17NS18NS19NS20NS21NS22NS23NS24NS25NS27NS29NS31NS05NS28NS11NS30 8D) Results and Analysis of Production and Injection Log surveys, tracer surveys, observation well surveys and any other special monitoring. No injection profiles and 6 production profiles were obtained in 2008. In addition to the production logs, Baker Gas/Fluid View logs were run in an attempt to understand fluid saturations in the reservoir. The following table summarized these as well as previous profile results. Well Name Well Type Date Log Type Shublik DIvishakZone EIvishakZone DIvishakZone C3IvishakZone C2IvishakZone C1IvishakZone BNS23 Injector 7/13/2003 Memory S/T/P 6 29 13 18 16 18NS27 Injector 7/21/2004 S/T/P 5 12 19 26 38NS13 Producer 10/4/2004 S/T/P/Gradio/Ghost 12 59 19 10NS08 Producer 12/7/2004 S/T/P/Gradio/Ghost/DEFT 55 31 9 5NS09 Producer 12/11/2004 S/T/P/Gradio 54 29 17 0NS24 Producer 3/26/2005 Memory S/T/P/Gradio 43 57 0NS24 Producer 3/27/2005 RST/Borax-PNLNS14 Producer 3/29/2005 S/T/P/Gradio/Ghost 55 43 2NS19 Producer 5/16/2005 Memory S/T/P 100NS14 Producer 6/26/2005 Memory S/T/P/FCAP 17 45 38NS06 Producer 6/30/2005 S/T/P/Gradio/Ghost 49 40 11NS28 Producer 8/20/2005 Memory S/T/P/DEFT/Ghost 100NS05 Producer 10/7/2005 Memory S/T/P 60 40 0NS16 Producer 5/5/2006 S/T/P/Gradio/Ghost 43 42 15NS11 Producer 12/20/2006 Memory S/T/P/DEFT/Ghost 82 18NS09 Producer 12/22/2006 S/T/P/Gradio 65 30 5NS08 Producer 4/10/2007 Memory S/T/P 20 0 27 53NS24 Producer 4/11/2007 Memory S/T/P 50 50NS19 Producer 4/24/2007 S/T/P/Gradio/Ghost/DEFT 98 2NS13* Producer 7/14/2007 Memory S/T/P/Gradio 0 100---NS15* Producer 5/10/2008 Memory S/T/P/Gradio 87 13-NS09 Producer 8/29/2008 Baker Gas/Fluid ViewNS24 Producer 8/30/2008 Baker Gas/Fluid ViewNS16A Producer 9/12/2008 S/T/P/Gradio/Ghost/DEFT 100 0NS16A Producer 9/16/2008 S/T/P/Gradio/Ghost/DEFT 100 0NS16A Producer 10/21/2008 S/T/P/Gradio/Ghost/DEFT 100 0NS24 Producer 12/3/2008 S/T/P/Gradio/Ghost 100 0NS24 Producer 12/5/2008 S/T/P/Gradio/Ghost 0 100 0* Did not log across entire perforation interval; therfore, unknown contibutions from open zones below logged interval are indicated by -.Percentage of flow from/to interval. Blank intervals are not perforated. 9 A tracer study was initiated in 2004. Unique chemical tracers were injected into the six Northstar gas injection wells (NS17, NS23, NS25, NS27, NS29 and NS31) on April 12, 2004. Gas samples are taken from key producer once per month. Results to date are shown in the following plots. 10NS05 Produced Tracer00.050.10.150.20.250.30.350 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS23Tracer Response NS27Tracer Response NS29Tracer Response NS31 11NS06 Produced Tracer0.0.050.10.150.20.250.30.350 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS27Tracer Response NS29Tracer Response NS23 12NS07 Produced Tracer0.0.10.20.30.40.50.60.70.80 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS27Tracer Response NS17Tracer Response NS23Tracer Response NS29 13 NS09 Produced Tracer0.0.10.20.30.40.50.60 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS23Tracer Response NS31Tracer Response NS27Tracer Response NS29 14 NS11 Produced Tracer00.020.040.060.080.10.120 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS17Tracer Response NS23Tracer Response NS25Tracer Response NS31Tracer Response NS27Tracer Response NS29 15NS12 Produced Tracer0.0.020.040.060.080.10.120.140 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS31Tracer Response NS27Tracer Response NS29Tracer Response NS17 16 NS15 Produced Tracer00.10.20.30.40.50.60 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS23Tracer Response NS17Tracer Response NS27Tracer Response NS29Tracer Response NS31 17 NS16A Produced Tracer00.10.20.30.40.50.6500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS23Tracer Response NS29 18 NS18 Produced Tracer0.0.10.20.30.40.50.60 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS17Tracer Response NS27Tracer Response NS29Tracer Response NS23 19 NS19 Produced Tracer0.0.020.040.060.080.10.120.140.160.180 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS23Tracer Response NS31Tracer Response NS27Tracer Response NS29Tracer Response NS17 20 NS20 Produced Tracer00.050.10.150.20.250 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS23Tracer Response NS17Tracer Response NS27Tracer Response NS29 21 NS21 Produced Tracer00.020.040.060.080.10.120 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS29Tracer Response NS17 22 NS22 Produced Tracer0.0.050.10.150.20.250 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS31Tracer Response NS27Tracer Response NS29Tracer Response NS17Tracer Response NS23Tracer Response NS25 23 NS24 Produced Tracer0.0.10.20.30.40.50.60.70.80.91.0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS23Tracer Response NS31Tracer Response NS29 24 NS30 Produced Tracer00.10.20.30.40.50.60.70 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS27Tracer Response NS29 25 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: ltheoreticaaof n whsi whfproduced QQP Phours =×⎟⎟ ⎠ ⎞ ⎜⎜ ⎝ ⎛ ⎟⎟ ⎠ ⎞ ⎜⎜ ⎝ ⎛−× 124 Where: hoursproduced = hours on line Pwhf = average wellhead flowing pressure Pwhsi = 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 Pwhsi ) 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. Allocation factors for 2008 had an average value of 1.12 26 F) Review of Annual Plan of Operations and Development and Future Development Plans Northstar concluded 2008 with six injection wells, nineteen producing wells and two Class I disposal wells on line. Historical well count is summarized in the following table. Northstar - Year End Wells Year Count Producers Injectors Class I Disposal 1 NS07 NS27 NS10 2 NS08 NS29 3 NS09 NS31 4 NS13 5 NS14 2002 6 NS15 1 NS07 NS27 NS10 2 NS08 NS29 3 NS09 NS31 4 NS13 NS17 5 NS14 NS23 6 NS15 7 NS24 8 NS18 9 NS22 10 NS06 11 NS12 12 NS19 2003 13 NS20 1 NS07 NS27 NS10 2 NS08 NS29 NS32 3 NS09 NS31 4 NS13 NS17 5 NS14 NS23 6 NS15 NS25 7 NS24 8 NS18 9 NS22 10 NS06 11 NS12 12 NS19 13 NS20 14 NS16 2004 15 NS21 27 Northstar - Year End 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 NS12 NS31 7 NS13 8 NS14 9 NS15 10 NS16 11 NS18 12 NS19 13 NS20 14 NS21 15 NS22 16 NS24 2005 17 NS28 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 12 NS18 13 NS19 14 NS20 15 NS21 16 NS22 17 NS24 18 NS28 2006 19 NS30 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 2007 12 NS18 28 Northstar - Year End Wells Year Count Producers Injectors Class I Disposal 13 NS19 14 NS20 15 NS21 16 NS22 17 NS24 18 NS28 19 NS30 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 NS16A 12 NS18 13 NS19 14 NS20 15 NS21 16 NS22 17 NS24 18 NS28 19 NS30 2008 20 NS34A Future Development Plans We recognize the possibility that satellite hydrocarbon accumulations may exist within expected drilling reach from the island. These targets will be the subject of additional appraisal. Infill wells and or sidetracks to optimize recovery from the Northstar pool are also possible. As of March 2009, drilling is ongoing on extended reach well NS33A (sidetrack of NS-33). It is anticipated to complete the well in the 2009 drilling season. 29 G) Status of Wells Shut-in for 365 days or More (20 AAC 25.115) No Northstar wells were shut-in for 365 days or more during 2008. Sw Name Date Shut- In Reason for Well Shut-In1 Current Mechanical Condition of Well2 Future Utility Plans & Possibilities3 Comments Northstar Shut-In Wells 2007 30 Attachment 1: MAP OF NORTHSTAR WELL LOCATIONS Well Status 12/31/08 Bottomhole Locations Abandoned Disposal Well Gas Injector Not Complete Oil Producer Sidetracked Well Ivishak Boundary Lease Boundary Unit Boundary Township / Range Boundary Northstar Well Status for AOGCC Annual Performance Report E. M. Fueg 1/12/09 Projection Information Alaska State Plane Zone 4 Clarke 1866, NAD 1927R13ER12E R14ER14ET14N T13N R13ER13ER12ER13ER13ER14E ADL312799 ADL312808 Y0181 Y0179 Y1645 ADL312798 ADL312809 NS21 NS20 NS33 NS25 NS28 NS15 NS14 NS29 NS16A NS08NS14A NS13 NS23 NS16 NS17 NS26 NS31 NS24 NS27NS07 NS10 NS32 NS05 NS11 NS19 NS06 NS09 NS30 NS12 NS34ANS22 NS18 bp LEGEND T R A N S - A L A S K A PIP E LIN E 32 MILES 10 31 Attachment 2 2008 12/31/2008 Full year (1)As of 12/08 (2) Producers 20 19 Injectors 8 8 2008 Cumulative Start-Up through 12/31/08 11,440,424 133,830,976 175,958,065 836,973,051 5,123,801 23,301,651 5,480,887 26,046,927 185,796,945 983,913,221 126,011 667,159 126,283 667,396 272 237 31,258 480,760 14,975 14,975 507,642 5097 psiaAverage of surveys obtained in 2008 Oil, BOPD Gas, MCF/D Water, BWPD Water, BWPD Gas, MCFPD Injection Balance (excludes satellite new well NS-34A oil Production ) AVERAGE RESERVOIR PRESSURE DAILY AVERAGE RATE DATA 2008 Production Cum Production (MRB) Cum Injection (MRB) Over/Under (MRB) Gas (MCF) Water (BBL) Injection Water (BBL) into NS10 & NS32 Disposal Wells Gas (MCF) NORTHSTAR FIELD 2008 OVERVIEW STATISTICAL SUMMARY WELL STATISTICS PRODUCTION/INJECTION STATISTICS Oil (BBL) Production NOTES: (1) Well count data reflects ONLY those wells which contributed to production/injection during the respective year (2) Active wells as of December 2008 32Attachment 3: Reservoir Pressure Report 6. Oil Gravity:428. Well Name and Number:9. API Number 50XXXXXXXXXXXX NO DASHES10. Type See Instructions11. AOGCC Pool Code12. Zone 13. Perforated Intervals Top - Bottom TVDSS14. Final Test Date15. Shut-In Time, Hours16. Press. Surv. Type (see instructions for codes)17. B.H. Temp.18. Depth Tool TVDSS19. Final Observed Pressure at Tool Depth20. Datum TVDSS (input)21. Pressure Gradient, psi/ft.22. Pressure at Datum (cal)NS08 50029230680000 O 590100 IVISHAK 11073-11094 1/13/2008 303 OTHER 199 8834 4801 11100 0.14 5115NS14A 50029230260100 O 590100 IVISHAK 11055-11094 1/21/2008 170 OTHER 248 10556 5028 11100 0.11 5089NS14A 50029230260100 O 590100 IVISHAK 11055-11094 2/9/2008 337 OTHER 248 10556 5027 11100 0.11 5088NS08 50029230680000 O 590100 IVISHAK 11073-11094 2/14/2008 15 OTHER 206 8834 4805 11100 0.14 5119NS28 50029232480000 O 590100 IVISHAK 11052-11094 2/18/2008 409 OTHER 244 10480 5024 11100 0.12 5101NS28 50029232480000 O 590100 IVISHAK 11052-11094 3/12/2008 456 OTHER 244 10480 5025 11100 0.12 5102NS28 50029232480000 O 590100 IVISHAK 11052-11094 3/31/2008 329 OTHER 245 10480 5022 11100 0.12 5099NS16A 50029230960000 O 590100 IVISHAK 11029-11090 4/5/2008 0 SBHP 262 11000 5070 11100 0.43 5107NS34A 50029230090000 O 590100 IVISHAK 11048-11091 4/20/2008 0 RFT 148 10953 5118 11102 0.12 5118NS15 50029230730000 O 590100 IVISHAK 11037-11087 4/21/2008 1560 SBHP 250 10950 5039 11100 0.36 5093NS14A 50029230260100 O 590100 IVISHAK 11055-11094 4/23/2008 24 OTHER 249 10556 5027 11100 0.11 5088NS28 50029232480000 O 590100 IVISHAK 11052-11094 4/24/2008 888 OTHER 244 10480 5024 11100 0.12 5101NS13 50029230170000 O 590100 IVISHAK 11055-11074 4/24/2008 36 OTHER 224 10390 4966 11100 0.13 5056NS08 50029230680000 O 590100 IVISHAK 11073-11094 4/28/2008 197 OTHER 201 8834 4804 11100 0.14 5118NS22 50029231280000 O 590100 IVISHAK 10988-11044 5/3/2008 144 SBHP 253 11059 5070 11100 0.20 5079NS19 50029231220000 O 590100 IVISHAK 10980-11000 5/4/2008 384 SBHP 252 11001 5053 11100 0.18 5071NS20 50029231180000 O 590100 IVISHAK 10990-11040 5/4/2008 792 SBHP 251 11044 5083 11100 0.23 5096NS30 50029232930000 O 590100 IVISHAK 10915-11021 5/4/2008 164 OTHER 241 10499 4929 11100 0.23 5065NS21 50029231260000 O 590100 IVISHAK 11002-11080 5/4/2008 164 OTHER 245 10576 4995 11100 0.23 5114NS05 50029232440000 O 590100 IVISHAK 10964-11084 5/5/2008 192 SBHP 253 11023 5043 11100 0.22 5060NS14A 50029230260100 O 590100 IVISHAK 11055-11094 5/11/2008 336 OTHER 245 10556 5025 11100 0.11 5086NS13 50029230170000 O 590100 IVISHAK 11055-11074 5/11/2008 456 OTHER 224 10390 4966 11100 0.13 5056NS28 50029232480000 O 590100 IVISHAK 11052-11094 5/18/2008 1464 OTHER 243 10480 5022 11100 0.12 5099NS24 50029231110000 O 590100 IVISHAK 11007-11047 5/23/2008 888 SBHP 250 11037 5084 11100 0.21 5097NS14A 50029230260100 O 590100 IVISHAK 11055-11094 5/24/2008 33 OTHER 248.64 10556 5030 11100 0.11 5091BP Exploration/Alaska Inc.P.O. Box 196612, Anchorage, Alaska 99519-66127. Gas Gravity:Northstar UnitNorthstar Field/Northstar Oil Pool -11,100 0.793. Unit or Lease Name:4. Field and Pool: 5. Datum Reference:STATE OF ALASKAALASKA OIL AND GAS CONSERVATION COMMISSIONRESERVOIR PRESSURE REPORT1. Operator:2. Address: 33NS09 50029230520000 O 590100 IVISHAK 11063-11084 5/24/2008 500 SBHP 251 10991 5042 11100 0.12 5055NS08 50029230680000 O 590100 IVISHAK 11073-11094 5/27/2008 57 OTHER 204 8834 4807 11100 0.14 5121NS08 50029230680000 O 590100 IVISHAK 11073-11094 6/16/2008 536 OTHER 201 8834 4805 11100 0.14 5119NS14A 50029230260100 O 590100 IVISHAK 11055-11094 6/16/2008 90 OTHER 249 10556 5029 11100 0.11 5090NS14A 50029230260100 O 590100 IVISHAK 11055-11094 6/25/2008 72 OTHER 248 10556 5024 11101 0.11 5085NS08 50029230680000 O 590100 IVISHAK 11073-11094 6/28/2008 72 OTHER 241 8834 4798 11100 0.14 5112NS28 50029232480000 O 590100 IVISHAK 11052-11094 6/30/2008 312 OTHER 244 10480 5007 11100 0.12 5084NS08 50029230680000 O 590100 IVISHAK 11073-11094 7/9/2008 168 OTHER 199 8834 4797 11100 0.14 5111NS14A 50029230260100 O 590100 IVISHAK 11055-11094 7/14/2008 144 OTHER 249 10556 5022 11100 0.11 5083NS28 50029232480000 O 590100 IVISHAK 11052-11094 7/24/2008 240 OTHER 245 10480 5000 11100 0.12 5077NS13 50029230170000 O 590100 IVISHAK 11055-11094 7/26/2008 264 OTHER 251 10390 4958 11100 0.13 5048NS08 50029230680000 O 590100 IVISHAK 11073-11094 8/17/2008 133 OTHER 200 8834 4792 11100 0.14 5106NS14A 50029230260100 O 590100 IVISHAK 11055-11094 8/17/2008 48 OTHER 250 10556 5022 11100 0.11 5083NS13 50029230170000 O 590100 IVISHAK 11055-11094 8/17/2008 24 OTHER 251 10390 4958 11100 0.13 5048NS21 50029231260000 O 590100 IVISHAK 11002-11080 8/17/2008 24 OTHER 245 10576 4928 11100 0.23 5047NS13 50029230170000 O 590100 IVISHAK 11055-11094 9/5/2008 480 OTHER 251 10390 4957 11100 0.13 5047NS28 50029232480000 O 590100 IVISHAK 11052-11094 9/7/2008 768 OTHER 245 10480 5001 11100 0.12 5078NS08 50029230680000 O 590100 IVISHAK 11073-11094 9/11/2008 1152 OTHER 199 8834 4795 11100 0.14 5109NS14A 50029230260100 O 590100 IVISHAK 11055-11094 9/22/2008 240 OTHER 250 10556 5018 11100 0.11 5079NS08 50029230680000 O 590100 IVISHAK 11073-11094 9/27/2008 1117 OTHER 205 8834 4795 11100 0.14 5109NS14A 50029230260100 O 590100 IVISHAK 11055-11094 9/27/2008 120 OTHER 248 10556 5018 11100 0.11 5079NS28 50029232480000 O 590100 IVISHAK 11052-11094 9/30/2008 1320 OTHER 245 10480 4994 11100 0.12 5071NS21 50029231260000 O 590100 IVISHAK 11002-11080 10/7/2008 24 OTHER 246 10576 4928 11100 0.23 5047NS14A 50029230260100 O 590100 IVISHAK 11055-11094 10/9/2008 168 OTHER 247 10556 5017 11100 0.11 5078NS13 50029230170000 O 590100 IVISHAK 11055-11094 10/10/2008 96 OTHER 231 10390 4953 11100 0.19 5085NS28 50029232480000 O 590100 IVISHAK 11052-11094 10/12/2008 1608 OTHER 243 10480 5004 11100 0.12 5081NS08 50029230680000 O 590100 IVISHAK 11073-11094 10/14/2008 576 OTHER 209 8834 4793 11100 0.14 5107NS14A 50029230260100 O 590100 IVISHAK 11055-11094 10/22/2008 192 OTHER 248 10556 5017 11100 0.11 5078NS13 50029230170000 O 590100 IVISHAK 11055-11094 11/2/2008 240 OTHER 231 10390 4949 11100 0.19 5081NS28 50029232480000 O 590100 IVISHAK 11052-11094 11/2/2008 2112 OTHER 243 10480 4995 11100 0.12 5072NS14A 50029230260100 O 590100 IVISHAK 11055-11094 12/5/2008 192 OTHER 248 10556 5016 11100 0.11 5077NS34A 50029230090000 O 590100 IVISHAK 11048-11091 12/16/2008 72 SBHP 249 11048 4894 11100 0.40 4915NS09 50029230520000 O 590100 IVISHAK 11063-11084 12/17/2008 96 SBHP 254 11049 5029 11100 0.14 5036 34NS13 50029230170000 O 590100 IVISHAK 11055-11094 12/27/2008 120 OTHER 231 10390 4948 11100 0.19 5080NS14A 50029230260100 O 590100 IVISHAK 11055-11094 12/31/2008 168 OTHER 248 10556 5013 11100 0.11 5074NS28 50029232480000 O 590100 IVISHAK 11052-11094 12/31/2008 3528 OTHER 244 10480 4986 11100 0.12 5063Comments: Surveys indicated as "OTHER" were obtained from Cidra data.Robert O. Younger23. All tests reported herein were made in accordance with the applicable rules, regulations and instructions of the Alaska Oil and Gas Conservation Commission.I hereby certify that the foregoing is true and correct to the best of my knowledge.SignaturePrinted NameTitleDateBPXA Northstar Lead Production EngineerMarch 20, 2009
