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Home My WebLink About2020 Endicott Oil PoolHilcorp Alaska, LLC Post Office Box 244027 Anchorage, AK 99524-4027 3800 Centerpoint Drive Suite 1400 Anchorage, AK 99503 Phone: 907/777-8486 Joleen.oshiro@hilcorp.com April 1st, 2021 Jeremy Price, Chair Alaska Oil & Gas Conservation Commission 333 W. 7th Avenue, Suite 100 Anchorage, Alaska 99501-3539 RE: DUCK ISLAND UNIT, ENDICOTT FIELD, ENDICOTT OIL POOL, STATE OF ALASKA, 2010 ANNUAL RESERVOIR REVIEW Dear Commissioner Price: In accordance with Conservation Order No. 462, Hilcorp Alaska, LLC (“Hilcorp”), as Operator, hereby submits for your review the following Annual Reservoir Review for the Endicott Field. This is the Annual Reservoir Review and corresponds to events during the 2020 calendar year. The Endicott Field has been on production since October 1987. A.Progress of Enhanced Recovery Project and Reservoir Management Summary During 2020, no new wells were drilled in the Duck Island Unit. Therefore the locations of all the wells in the Northstar Unit have remained unchanged. Production and injection statistics are summarized in Table 1. Average daily oil production from the Endicott Oil Pool was 6,641 bopd and average daily gas injection was 336 mmscfpd. During 2020, injected fluid was calculated to be 9,968 thousand-reservoir barrels (MRB) less than reservoir voidage. At year end, the reservoir overall cumulative voidage replacement ratio was 0.93. The average reservoir pressure varies between zones. The average of surveys run in 2020 was 3,951 psia. Hilcorp became the official operator of the Endicott Field effective November 18, 2014. As a result, the historic reservoir simulation model developed by the previous operator will no longer will be utilized in the enhanced recovery or reservoir management. Hilcorp will continue to identify and improve waterflood pattern efficiency by allocating existing water injection volumes and adding perforations in active injection wells. Hilcorp progressed modeling of the SDI portion of the Kekiktuk K2B reservoir. The model was used to study and sanction additional attic oil recovery with lean gas injection from SDI. This project was initiated in January 2020. Page 2 B.Voidage Balance by Month of Produced Fluid and Injected Fluids – 2020 As of 12/31/2020 Full year (1)As of Dec-20 (2) Producers 58 58 Injectors 26 26 2020 Cumulative Start- Up through 12/31/20 2,430,130 481,667,164 134,992,174 3,791,309,769 87,242,408 1,919,311,135 87,626,568 2,264,161,407 122,799,232 3,375,689,176 181,503,680 4,907,182,239 171,535,283 4,530,762,619 -9,968,397 -376,419,620 6,641 368,894 238,429 239,483 335,577 3,951 psiaAverage of surveys obtained in 2020 Water, BWPD Injection Water, BWPD Gas, MCFPD AVERAGE RESERVOIR PRESSURE DAILY AVERAGE RATE DATA 2020 Production Oil, BOPD Gas, MCF/D Gas (MCF) Balance Cum Production (MRB) Cum Injection (MRB) Over/Under (MRB) Oil (BBL) Gas (MCF) Water (BBL) Injection Water (BBL) (1) Well count data reflects ONLY those w ells which contributed to production/injection during the respective year (2) Active wells as of December 2020 PRODUCTION/INJECTION STATISTICS Production Table 1: ENDICOTT FIELD 2020 OVERVIEW STATISTICAL SUMMARY WELL STATISTICS NOTES: Page 3 C.Summary and Analysis of reservoir pressure surveys within the pool The following key wells in the Endicott Pool were proposed in 2020: 2020 Key Well Program 1-09A K2A, K2B 2-70 K3B, K3C 4-14A K3B, K3C 1-17A K3A 3-01 K2A 4-18 K3C 1-25A K1 3-23A K2B 1-11 SDN - Ivishak 2-14 K3A, K2B 4-38 K2A, K2B 2-56A Sag River - Eider Endicott Oil Pool & Ivishak Datum:-10,000 ssTVD Eider Oil Pool Datum: -9,700 ssTVD Static bottomhole pressures collected in 2020 are summarized and submitted quarterly on the form 10-412 form below. Produced water injector well 3-01’s reservoir pressure survey was replaced with a reservoir pressure survey in produced water injector 5-02. Month Oil, RB Free Gas, RB Water, MRB Total Voidage, MRB Year Cum, MRB Cum since start-up, MRB Formation Gas, MRB Water, MRB Total Injection, MRB Year Cum, MRB Cum since start-up, MRB Net Injection, MRB Year Cum, MRB Cum since start-up, MRB Jan-2020 277,760 7,649,949 7,423,221 15,350,930 15,350,930 4,732,415,036 7,030,798 7,436,231 14,467,029 14,467,029 4,398,856,806 -883,901 -883,901 -333,558,229 Feb-2020 265,012 7,200,642 7,091,758 14,557,412 29,908,342 4,746,972,448 6,638,853 7,118,667 13,757,520 28,224,549 4,412,614,326 -799,893 -1,683,794 -334,358,122 Mar-2020 290,765 7,751,632 7,543,933 15,586,330 45,494,672 4,762,558,778 7,174,963 7,494,076 14,669,039 42,893,588 4,427,283,365 -917,291 -2,601,085 -335,275,413 Apr-2020 274,037 7,523,381 7,435,520 15,232,938 60,727,611 4,777,791,716 6,951,676 7,477,075 14,428,751 57,322,339 4,441,712,116 -804,187 -3,405,272 -336,079,600 May-2020 258,386 7,136,330 6,656,646 14,051,361 74,778,972 4,791,843,078 6,566,837 6,652,045 13,218,882 70,541,221 4,454,930,998 -832,480 -4,237,751 -336,912,080 Jun-2020 276,271 7,481,789 6,909,334 14,667,394 89,446,367 4,806,510,472 6,926,588 6,975,629 13,902,217 84,443,438 4,468,833,215 -765,177 -5,002,928 -337,677,257 Jul-2020 291,746 7,597,641 7,473,681 15,363,068 104,809,434 4,821,873,540 7,015,260 7,542,297 14,557,557 99,000,995 4,483,390,772 -805,511 -5,808,439 -338,482,768 Aug-2020 281,332 7,596,598 7,467,719 15,345,650 120,155,084 4,837,219,190 7,006,836 7,522,396 14,529,232 113,530,227 4,497,920,004 -816,417 -6,624,857 -339,299,185 Sep-2020 268,891 7,448,831 7,233,365 14,951,086 135,106,171 4,852,170,276 6,869,358 7,272,735 14,142,093 127,672,321 4,512,062,098 -808,993 -7,433,850 -340,108,178 Oct-2020 256,173 7,631,974 6,967,458 14,855,604 149,961,775 4,867,025,881 7,033,033 7,026,723 14,059,756 141,732,077 4,526,121,854 -795,848 -8,229,698 -340,904,027 Nov-2020 264,068 7,868,005 7,343,276 15,475,348 165,437,123 4,882,501,229 7,242,856 7,381,465 14,624,321 156,356,399 4,540,746,175 -851,027 -9,080,725 -341,755,054 Dec-2020 278,665 8,091,395 7,696,497 16,066,557 181,503,680 4,898,567,786 7,451,656 7,727,229 15,178,885 171,535,283 4,555,925,060 -887,672 -9,968,397 -342,642,726 3,283,106 90,978,167 87,242,408 181,503,680 83,908,715 87,626,568 171,535,283 -9,968,397 Produced Fluids Injected Fluids (Injection - Production) Page 4 The following key wells in the Endicott Pool will have static bottomhole pressure measurements captured in 2021; 2020 Key Well Program 1-09A K2A, K2B 2-64 K3C 4-42 K3C 1-17A K3A 2-70 K3B, K3C 1-11 Ivishak 2-14 K3A 3-47 K3B, K3C 2-56A Sag River - Eider 2-22 K3A, K3B, K3C 4-38 K2A, K2B Endicott Oil Pool Datum:-10,000 ssTVD Eider Oil Pool Datum: -9,700 ssTVD Page 5 D.Summary and Analysis of Gas-Oil Contact or Gas Monitoring Surveillance Plan. The following table summarizes the results of the logs run in 2020 for gas monitoring. A field wide current GOC is not likely to be identified as the Kekiktuk sands have several subzones that are vertically separated and have different permeability. In addition, faulting in the reservoir may lead to hydraulic isolation or partial pressure communication within a sub zone. E.The Following Year Gas-Oil Contact or Gas Monitoring Surveillance Plan. In 2020, we will run at least one cased hole pulsed neutron logs. The logs will be used to monitor GOC and any potential remaining oil zones following additional rig intervention/workover. Additional candidates may be identified and logged to continue GOC surveillance of the Endicott Oil Pool. F.Results and Analysis of Production and Injection log surveys, tracer surveys, observation well surveys and any other special monitoring One production profile was obtained in 2020. A 2021 waterflood DNA tracer program is planned for late 2021 initiation, to monitor K2B and K3A fluid movement patterns. G. Future Development Plans & Review of Annual Plan of Operations and Development In 2020, Hilcorp increased unit production through well intervention projects and other optimization opportunities. The ongoing field study of the Duck Island Unit ongoing updates with additional well intervention results. The re-mapping of horizons, analyzing production and injection data, and geophysical work is ongoing. Some additional wellwork was initiated due to data provided by surveillance activities, summarized below. Page 6 Projects completed during the 2020 calendar year: ·MPI 1-31 (Prod) - Endicott Oil Pool – Kekiktuk K2A (Non-rig) – Twin surface flowlines (March 2020) ·MPI 2-48 (Prod) - Endicott Oil Pool – Kekiktuk K3A (Non-rig) – Twin surface flowlines (March 2020) ·MPI 2-68 (Prod) - Endicott Oil Pool – Kekiktuk K3C, K3B (Non-rig) – Twin surface flowlines (May 2020) ·SDI 4-10A (Prod) - Endicott Oil Pool – Kekiktuk K2B (Non-rig) – Quad surface flowlines (May 2020) ·MPI 1-25A (Prod) - Endicott Oil Pool – Kekiktuk K2A (Non-rig) – Add Perforations (July 2020) ·MPI 2-28B (Prod) - Endicott Oil Pool – Kekiktuk K2B (Non-rig) – Liner patch pull and twin surface flowlines (August 2020) ·MPI 2-14 (Prod) - Endicott Oil Pool – Kekiktuk ____ (Non-rig) – Add Perforations (Dec 2020) ·SDI 4-26A (Prod) – Endicott Oil Pool – Kekiktuk K2B (Non-rig) – GINJ Conversion (December 2019/January 2020); ·SDI High Flow test separator upgrade In 2021, Hilcorp will pursue increased unit production through additional well intervention projects, any necessary infrastructure and facility repairs, and other optimization opportunities as they arise.Slickline, e-line, coiled tubing, and other rigless interventions and planned throughout the year. Workover operations may be planned for 2021 execution. No drilling activities are planned at Endicott within the 2021 calendar year. Projects planned for the 2021 calendar year: ·Add Perfs in existing production wells o Add perf in bypassed pay in Endicott Oil Pool. o Identify additional oil pay with gas saturation logging ·Perform WSO/GSO o Identify excessive water or gas production with PPROF/RST logging o Perform water/gas shut off using wireline/coil. ·Perform water/gas flood maintenance work o Run several static BHP surveys or IPROF logs to identify unhealthy water flood patterns ·MPI & SDI – possible opportunities such as RWO(s), return long-term-shut-in-wells to service, downhole integrity mitigations, producer-to-injector conversion(s), and injector-to-producer conversion(s) will be evaluated and possibly executed. ·Facility Work: o Upgrade SDI test separator High Flow and Low Flow separator o TEG contactor internals removal/inspection/reinstall o NGL reboiler inspection/cleaning o TEG plate exchanger clean-out o Propane turbine overhaul o Propane seal oil demister install o Vessel inspections (multiple) Hilcorp will continue to progress the field study of the Duck Island Unit. This may include re-mapping potentially productive horizons, updating well histories, reviewing all production and injection data, material balance calculations, and reviewing results of recent well intervention projects. Page 7 Sincerely, Joleen Oshiro Reservoir Engineer - Endicott