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Home My WebLink About2006 Northstar Oil Pool Annual Reservoir Performance Report Northstar Field Northstar Oil Pool Januar y 2006 through December 2006 March, 2007 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 2006 Overview Statistical Summary Attachment 3: Northstar Field 2006 Reservoir Pressure Report, Form 10-412 3 A) Progress of Enhanced Recovery Project During 2006, two additional production wells (NS11 and NS30) were brought on line. One production well was sidetracked to a new location (NS14). The locations of these wells in addition to the other Northstar wells are shown in Attachment 1. Production and injection statistics are summarized in Attachment 2. Average oil production was 51,729 bopd and average gas injection was 449.5 mmscfd. During 2006, gas injection was greater than reservoir voidage. At year end, the reservoir had an overall cumulative voidage replacement ratio of 0.998. 4 B) Voidage Balance by Month of Produced Fluid and Injected Fluids – 2006 2006 Notes: • Jan-2006 Oil MRB does not include oil produced from Kuparuk reservoir test (9 MRB) • Jan-2006 Formation Gas MRB does not include gas produced from Kuparuk reservoir test (70 MRB) • Jan-2006 Import Gas MRB includes gas produced from Kuparuk reservoir test (70 MRB) 5 C) Summary and Analysis of reservoir pressure surveys within the pool Static bottom hole pressures collected in 2006 are summarized below. Well Date Extrapolated Pressure at -11,100' TVDss Datum, psia Data Source NS05 1/7/2006 5,070 Cidra Data NS21 1/13/2006 5,077 Cidra Data NS28 1/21/2006 5,104 Cidra Data NS28 2/27/2006 5,099 Cidra Data NS28 3/8/2006 5,099 Cidra Data NS08 3/29/2006 5,147 Cidra Data NS30 4/15/2006 5,169 Cidra Data NS28 4/18/2006 5,100 Cidra Data NS14A 5/24/2006 5,175 SBHP NS11 5/30/2006 5,108 Cidra Data NS14A 5/31/2006 5,128 Cidra Data NS09 6/3/2006 5,097 SBHP NS13 6/4/2006 5,113 SBHP NS15 6/4/2006 5,110 SBHP NS07 7/23/2006 5,121 SBHP NS12 7/23/2006 5,051 SBHP NS14A 7/23/2006 5,122 Cidra Data NS30 7/23/2006 5,000 Cidra Data NS05 7/23/2006 5,077 Cidra Data NS21 7/23/2006 5,084 Cidra Data NS08 7/23/2006 5,077 Cidra Data NS16 8/20/2006 5,103 SBHP NS13 9/14/2006 5,098 Cidra Data NS28 9/19/2006 5,121 Cidra Data NS28 10/8/2006 5,090 Cidra Data NS05 10/11/2006 5,116 Cidra Data NS13 10/17/2006 5,099 Cidra Data NS21 11/16/2006 5,127 Cidra Data NS08 11/19/2006 5,144 Cidra Data NS30 11/22/2006 5,073 Cidra Data NS13 12/11/2006 5,098 Cidra Data NS14A 12/11/2006 5,165 Cidra Data NS21 12/11/2006 5,100 Cidra Data NS08 12/11/2006 5,167 Cidra Data NS11 12/11/2006 5,124 Cidra Data NS28 12/12/2006 5,136 Cidra Data 6 These pressures are graphically represented in the next figure that is a plot of pressure by well versus time. These data indicate average pressures were essentially unchanged during 2006 (from 5,115 psi to 5,108 psi). 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-01Nov-01Dec-01Jan-02Mar-02Apr-02May-02May-02Jul-02Jul-02Aug-02Sep-02Oct-02Nov-02Dec-02Jan-03Mar-03Mar-03May-03May-03Jul-03Jul-03Aug-03Sep-03Oct-03Nov-03Dec-03Jan-04Feb-04Mar-04Apr-04May-04Jun-04Jul-04Aug-04Sep-04Oct-04Nov-04Dec-04Jan-05Feb-05Mar-05Apr-05May-05Jun-05Jul-05Aug-05Sep-05Oct-05Nov-05Dec-05Jan-06Feb-06Mar-06Apr-06May-06Jun-06Jul-06Aug-06Sep-06Oct-06Nov-06Dec-06Jan-07Feb-07Mar-07Pressure (PSIA)Pressure, psiaNS06NS07NS08NS09NS12NS13NS14NS15NS16NS18NS19NS20NS21NS22NS24NS25NS05NS28NS11NS30NS17NS23NS27NS29NS31 8 D) Results and Analysis of Production and Injection Log surveys, tracer surveys, observation well surveys and any other special monitoring. No injection profiles and 3 production profiles were obtained in 2006. The following table summarized these as well as previous profile results. Well NameWell TypeDateTypeShublik D Ivishak Zone E Ivishak Zone D Ivishak Zone C3 Ivishak Zone C2 Ivishak Zone C1 Ivishak Zone BNS23Injector7/13/2003Memory S/T/P62913181618NS27Injector7/21/2004S/T/P512192638NS13Producer10/4/2004S/T/P/Grad/Ghost/DEFT12591910NS08Producer12/7/2004S/T/P/Gradio/Ghost553195NS09Producer12/11/2004S/T/P/Gradio5429170NS24Producer3/26/2005Memory S/T/P/Gradio43570NS24Producer3/27/2005RST/Borax-PNLNS14Producer3/29/2005S/T/P/Gradio/Ghost55432NS19Producer5/16/2005Memory S/T/P100NS14Producer6/26/2005Memory S/T/P/FCAP174538NS06Producer6/30/2005S/T/P/Gradio/Ghost494011NS28Producer8/20/2005Memory S/T/P/DEFT/Ghost100NS05Producer10/7/2005Memory S/T/P60400NS16Producer5/5/2006S/T/P Gradio/ Ghost434215NS11Producer12/20/2006Memory S/T/P/DEFT/Ghost8218NS09Producer12/22/2006S/T/P Gradio65305Percentage of flow from/to interval. Blank intervals are not perforated. 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 each producer once every two weeks. Results to date are shown in the following plots. 9 NS05 Produced Tracer00.050.10.150.20.250.30.3501002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS23Tracer Response NS31Tracer Response NS27Tracer Response NS29 10 NS06 Produced Tracer0.0.050.10.150.20.250.30.3501002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS27Tracer Response NS29 11 NS07 Produced Tracer0.0.050.10.150.20.250.30.3501002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS27Tracer Response NS29 12 NS08 Produced Tracer0.0.20.40.60.81.1.201002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS23Tracer Response NS31Tracer Response NS27Tracer Response NS29 13 NS09 Produced Tracer0.0.10.20.30.40.50.601002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS23Tracer Response NS31Tracer Response NS27Tracer Response NS29 14 NS11 Produced Tracer00.10.20.30.40.50.60.70.80.9101002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS17Tracer Response NS23Tracer Response NS25Tracer Response NS31 15 NS12 Produced Tracer0.0.020.040.060.080.10.120.1401002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS31 16 NS13 Produced Tracer0.0.20.40.60.81.1.21.41.61.82.01002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS23Tracer Response NS17Tracer Response NS31Tracer Response NS27Tracer Response NS29 17 NS14 Produced Tracer00.10.20.30.40.50.60.70.80.9101002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS23Tracer Response NS29 18 NS15 Produced Tracer00.10.20.30.40.50.601002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS23Tracer Response NS17Tracer Response NS27Tracer Response NS29 19 NS16 Produced Tracer0.0.10.20.30.40.50.60.70.80.91.01002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS23Tracer Response NS29 20 NS18 Produced Tracer0.0.10.20.30.40.50.601002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS17Tracer Response NS27Tracer Response NS29 21 NS19 Produced Tracer0.0.020.040.060.080.10.120.140.160.1801002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS23Tracer Response NS31Tracer Response NS27Tracer Response NS29 22 NS20 Produced Tracer00.050.10.150.20.2501002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS23Tracer Response NS17Tracer Response NS27Tracer Response NS29 23 NS21 Produced Tracer00.010.020.030.040.050.060.070.080.090.101002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS29 24 NS22 Produced Tracer0.0.020.040.060.080.10.120.140.160.1801002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS31Tracer Response NS27Tracer Response NS29 25 NS24 Produced Tracer0.0.10.20.30.40.50.60.70.80.91.01002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS23Tracer Response NS31Tracer Response NS29 26 NS28 Produced Tracer00.050.10.150.20.250.30.350.40.450.501002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS27Tracer Response NS29 27 NS30 Produced Tracer00.020.040.060.080.10.1201002003004005006007008009001000Days After Injectionconcentration (pm)Tracer Response NS25Tracer Response NS27Tracer Response NS29 28 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 2006 had an average value of 1.11. 29 F) Review of Annual Plan of Operations and Development and Future Development Plans Northstar concluded 2006 with six injection wells, nineteen producing wells and two Class I disposal wells on line. During 2006, the NS11 and NS30 producers were brought on line and NS14 was sidetracked to a new location. This drilling activity 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 30 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 MMS W ells in Bold 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. 31 As of March 2007, drilling is ongoing on one infill well (NS33) and a second well targeting a location outside the Northstar PA (NS34) is temporarily suspended. Timing for the resumption of the NS34 well is under evaluation. 32 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 2006. 33 Attachment 1: MAP OF NORTHSTAR WELL LOCATIONS W ell Status 12/31/06 Bottomhole Locations Abandoned Disposal Well Gas Injector Not Complete Oil Producer Sidetracked W ell Ivishak Boundary Lease Boundary Unit Boundary Township / Range Boundary Northstar Well Status for AOGCC Annual Performance Report E. M. Fueg 2/5/07 Projection Information Alaska State Plane Zone 4 Clarke 1866, NAD 1927R13ER12E R14ER14ET14N T13N R13ER13ER12ER13ER13ER14ER13EADL312799 Y0179 ADL312808 ADL312798 Y1645 Y0181 ADL312809 NS14NS15 NS13 NS26 NS33 NS05 NS06 NS07 NS08 NS09 NS10 NS11 NS12NS14A NS16 NS17 NS18 NS19 NS20 NS21 NS22 NS23 NS24 NS25 NS27 NS28 NS29 NS30 NS31 NS32 NS34 bp LEGEND T R A N S - ALA S K A PIP ELIN E 32 MILES 10 34 Attachment 2 NORTHSTAR FIELD 2006 OVERVIEW STATISTICAL SUMMARY WELL STATISTICS 2006 (12/31/06) Full year (1) As of 12/06 (2) Producers 19 19 Injectors 8 8 NOTES: (1) Well count data reflects ONLY those wells which contributed to production/injection during the respective year (2) Active wells as of December 2006 PRODUCTION/INJECTION STATISTICS Production 2006 Cumulative: Start-Up through 12/31/06 Oil (BBL) 18,877,092 108,513,279 Gas (MCF) 142,192,520 509,870,080 Water (BBL) 5,110,288 13,342,142 Injection W ater (BBL) into NS10 & NS32Disposal W ell 5,455,123 15,349,765 Gas (MCF) 164,065,661 630,640,343 Balance Cum Production (MRB) 111,028 427,978 Cum Injection (MRB) 111,489 427,300 Over/Under (MRB) 461 -678 DAILY AVERAGE RATE DATA 2006 Production Oil, BOPD 51,718 Gas, MCF/D 389,569 W ater, BW PD 14,001 Injection W ater, BW PD 14,946 Gas, MCFPD 449,495 AVER AGE RESERVOIR PRESSURE Average of surveys obtained in 2006, psia 5,108 Notes: • 2006 Oil and Cum Oil does not include oil produced from Kuparuk reservoir test (9 MRB, 4,087 BBL) • 2006 Gas and Cum Gas does not include gas produced from Kuparuk reservoir test (70 MRB, 103,742 MCF) • 2006 Cum Injection includes gas produced from Kuparuk reservoir test (70 MRB) 35 Attachment 3 Northstar Field 2006 Reservoir Pressure Report, Form 10-412