The URL can be used to link to this page

Home My WebLink About2020 Greater Point McIntyre Area 3800 Centerpoint Drive, Suite 1400, Anchorage, AK 99503 Phone: 907/777-8300 hilcorp.com Hilcorp North Slope, LLC June 15, 2021 Jeremy Price, Chair Alaska Oil and Gas Conservation Commission 333 West 7th Avenue, Suite 100 Anchorage, AK 99501 Re: Prudhoe Bay Unit GPMA Annual Reservoir Reports, Annual Reservoir Property Reports April 1, 2020 – March 31, 2021 Chairman Price, Hilcorp North Slope, LLC, as operator of the Prudhoe Bay Unit, submits the enclosed Annual Reservoir Surveillance Reports for the Greater Point McIntyre Area (GPMA) Oil Pools covering the time period from April 1, 2020 through March 31, 2021. These Annual Reservoir Reports were prepared in accordance with the latest conservation orders for each pool. In addition, Hilcorp North Slope will simultaneously file the Annual Reservoir Properties Reports (ARPs, form 10-428) for the GPMA Oil Pools under this cover and to aogcc.reporting@alaska.gov. The Operators of the Prudhoe Bay Field reserve the right to alter the content of the analyses contained in this report at any time based upon the most recent surveillance information obtained. If you have any questions regarding the reports, please contact Abbie.Barker@hilcorp.com. Thank you, Tommy Nenahlo Senior Reservoir Engineer, GPMA Hilcorp North Slope, LLC Cc: Alex Youngmun, ConocoPhillips Alaska, Inc. Greg Keith, ConocoPhillips Alaska, Inc. Doug Sturgis, ExxonMobil Alaska, Production Inc. Jeff Farr, ExxonMobil Alaska, Production Inc. Gary Selisker, Chevron USA Dave Roby, AOGCC Aaron O’Quinn, DNR, Division of Oil & Gas Kevin Pike, DNR, Division of Oil & Gas Lisburne Oil Pool Page 1 ASR for Apr ’20 – Mar’21 Prudhoe Bay Unit Lisburne Oil Pool 2021 Annual Reservoir Surveillance Report This Annual Reservoir Report for the period ending March 31, 2021 is submitted to the Alaska Oil and Gas Conservation Commission for the Lisburne Oil Pool in accordance with commission regulations and Conservation Order 207D. This report covers the period from April 1, 2020 through March 31, 2021. A. Reservoir Management 1. Summary Oil production and reservoir management activity in the Lisburne Oil Pool continues under gas cap expansion supported by gas injection at LGI pad and water injection at L5-29. In the Central area, pressure support is supplemented by weak aquifer influx. Pilot seawater injection projects have been on-going in the central Alapah (NK-25), the southern periphery Wahoo (04-350) and the mid-field Wahoo (L5-15) area. Production and injection volumes for the 12-month period ending March 31, 2021 are summarized in Table 1. Oil production volumes include allocated crude oil, condensate and NGL production. 2. Reservoir Pressure Surveys Within the Pool A summary of reservoir pressure surveys obtained during the reporting period is shown in Table 2. The proposed number of Lisburne reservoir pressure surveys to be obtained in the coming plan year April 1 2021 to March 31, 2022 is six total. One apiece at each of the major Lisburne pads (L1, L2, L3, L4 & L5) and one in the Lisburne West Alapah accumulation (well NK-25 or NK-26A). 3. Results and Analysis of Production Logging Surveys There were no production logs obtained from Lisburne wells during the reporting period. Lisburne Oil Pool Page 2 ASR for Apr ’19 – Mar’20 B. Development and Production Activity 1. Enhanced Recovery Projects a. L5 Gas Cap Water Injection Surveillance (C.O. 207C) The L5 GCWI pilot project commenced injection in July of 2008. The initial injection rate was 2 mbd, and over time has been gradually increased to approximately 17 mbd. As of March 31, 2021, the cumulative volume of seawater injected in L5-29 was 24,420 mbbls. The L5-29 pilot injection demonstrated positive results with likely injection water breakthrough occurring in four offset producer wells (L5-28A, L5-32, L5-33 & L5-36). Pressure response has also been observed in offset wells. The GCWI Pilot was approved for permanent injection under AOGCC Conservation Order 207B.16. The injector was on-line for a portion of the time (60 days) during the reporting period. Three pressure fall-off (PFO) tests have been conducted in the L5-29 gas cap water injection well. The PFO analyses show a constant pressure boundary, and skin values of between -3.6 and -3.8. Based on these results, it is inferred that no fracture extension is occurring. Offset well annuli pressures are reported monthly to the Commission by the Hilcorp Well Integrity Engineer via the Monthly Injection Report sent to the AOGCC. b. Waterflooding Pilot Projects A review of the Lisburne development plan identified water injection as a mechanism to provide additional pressure support in the Lisburne reservoirs. A grass roots injection well, 04-350, was completed on the southern periphery of the Wahoo Formation in November 2011 and has injected 8,912 mbbls of seawater as of March 31, 2021. Seawater production has been observed in offset producers L3-22, L3-22A, L3-24 and L3-30. Another pilot water injection project has been undertaken in the mid-field area. Wahoo production wells L5-15 and L5-13 were converted to seawater injection service in March 2013. As of March 31, 2021 the cumulative volume of seawater injected in both these wells was 12,031 mbbls. Confirmed seawater production has occurred in offset L5-16A and L5-17A. L5-13 developed mechanical integrity issues and was plugged and abandoned in November 2017. In addition, a pilot water injection project into the Alapah Formation has been initiated from the Niakuk Heald Point pad. Alapah producer NK-25 Lisburne Oil Pool Page 3 ASR for Apr ’19 – Mar’20 was converted to seawater injection service in March 2013 and has injected 10,581 mbbls of seawater as of March 31, 2021. Offset producer well pressure response and seawater production have been observed. 2. Well Activity: Drilling Rig One new well (L5-07) was drilled & completed into the Lisburne Formation during the reporting period. 3. Well Activity: Non-Rig The L4 Drill Site was reinstated in late March 2021, bringing online production that had been shut in since 2014. Rate-adding non-rig interventions were also performed during the reporting period. These rate-adding interventions included perforations, hydrate & paraffin removal, hot oil treatment (HOT) jobs, acid stimulations, gas-lift work, profile modifications, fill cleanouts, well integrity repairs, SSSV replacements, continuous methanol injection for hydrate mitigation, and surface component repairs. 4. Other Activity a. Plant and Pipelines Various scheduled minor plant and pipeline repairs and modifications were completed to protect or enhance production from the Lisburne during the reporting period. b. Support Facilities Lisburne shares North Slope infrastructure with the Point McIntyre and Niakuk Fields. Nine wells from the IPA can produce to the LPC as part of the L2 Re-route Project: L2-03A, L2-07A, L2-08A, L2-11, L2-13A, L2-14C, L2-18A, L2-21B and L2-29A. c. Production Allocation The production of oil and gas, including those hydrocarbon liquids reported as NGLs, is allocated to the Lisburne Participating Area in accordance with conditions approved by the Alaska Department of Natural Resources, Alaska Department of Revenue, and Alaska Oil and Gas Conservation Commission. There is a test separator at each Lisburne Drill Site. Lisburne Oil Pool Page 4 ASR for Apr ’19 – Mar’20 5. Future Development Plans (C.O. 207) Lisburne Pool oil is predominantly processed at the Lisburne Production Center, which began permanent operation in December 1986. There are currently 84 development wells in the Lisburne Oil Pool. Future development plans are discussed in the 2020 Lisburne Plan of Development filed with the Division of Oil and Gas of the Alaska Department of Natural Resources, which the Commission received. The Commission will be copied when the 2021 update of the Lisburne Plan of Development is filed with the Division. Lisburne Oil Pool Page 5 ASR for Apr ’19 – Mar’20 Tables & Figures Oil + NGL Gas Water Oil + NGL Gas Water Monthly Cum Monthly Cum Date mstbo mmscf mbw mstbo mmscf mbw mmscf bscf mbw mbw 4/1/2020 363.831 5,918 512 202,017 2,283,370 75,931 5,335 2,197,314 552 61,169 5/1/2020 336.146 5,899 396 202,353 2,289,269 76,327 5,390 2,202,704 460 61,629 6/1/2020 310.058 5,403 367 202,663 2,294,672 76,695 5,311 2,208,015 402 62,031 7/1/2020 296.823 5,432 366 202,960 2,300,104 77,060 4,667 2,212,683 426 62,457 8/1/2020 358.916 6,527 438 203,319 2,306,631 77,498 5,370 2,218,052 294 62,751 9/1/2020 369.358 6,155 472 203,688 2,312,785 77,970 5,188 2,223,240 106 62,858 10/1/2020 372.133 6,485 496 204,060 2,319,270 78,467 5,413 2,228,653 423 63,281 11/1/2020 377.459 6,885 394 204,438 2,326,154 78,861 5,677 2,234,330 387 63,668 12/1/2020 379.672 7,075 379 204,817 2,333,229 79,240 6,231 2,240,562 483 64,151 1/1/2021 381.215 7,412 344 205,198 2,340,641 79,584 6,047 2,246,609 522 64,673 2/1/2021 330.695 6,465 285 205,529 2,347,106 79,869 5,747 2,252,356 452 65,126 3/1/2021 377.89 7,100 346 205,907 2,354,206 80,214 5,613 2,257,968 483 65,608 Table 1 - Lisburne Monthly Production & Injection Volumes Monthly Production Cumulative Production Gas Injection Water Injection Table 2 - Lisburne Pressure data April 1, 2020 to March 31, 2021 Well Name Survey Date Pressure (psi) (Datum = 8900' SS) L3-30 5/29/2020 2750 L3-30 5/30/2020 2750 Niakuk Oil Pool Page 1 ASR for Apr ’20 – Mar ‘21 Prudhoe Bay Unit Niakuk Oil Pool 2021 Annual Reservoir Surveillance Report This Annual Reservoir Surveillance Report is submitted to the Alaska Oil and Gas Conservation Commission for the Niakuk Oil Pool in accordance with commission regulations and Conservation Order No. 329A. This report covers the period from April 1, 2020 through March 31, 2021. A. Reservoir Management 1. Summary Oil production and reservoir management activity in the Niakuk Oil Pool continues under waterflood. Reservoir management activity in the Niakuk Oil Pool includes: 1) selective perforating and profile modifications to manage conformance of the waterflood, 2) production and injection profile logging to determine current production and injection zones for potential profile modifications, material balance calculations, and effective full field modeling, 3) pressure surveys to monitor flood performance and 4) analysis of production, Gas Oil Ratio, and Water Oil Ratio trends to highlight poorer performing wells for possible intervention activity. Production and injection volumes and resultant voidage data by month for the 12-month period ending March 31, 2020 are summarized in Tables 1 and 2. 2. Reservoir Pressure Surveys Within the Pool A summary of reservoir pressure surveys obtained during the reporting period is shown in Table 3. The proposed number of Niakuk reservoir pressure surveys to be obtained in the coming plan year April 1, 2021 to March 31, 2022 is three total. One survey apiece in each of the major Niakuk reservoir sector delineations (Segments 1, 2/4 and 3/5) 3. Results of Production Logging, Tracer and Well Surveys (C.O. 329A Rule 9d) No production logs were run during the reporting period. No tracer surveys were performed during this reporting period. Niakuk Oil Pool Page 2 ASR for Apr ’20 – Mar ‘21 B. Development and Production Activity 1. Enhanced Recovery Projects a. Progress of Niakuk Waterflood Project Implementation and Reservoir Management Summary (C.O. 329A Rule 9a) The Niakuk waterflood was started in April 1995, in conjunction with the commissioning of permanent facilities at Heald Point, using water from the Initial Participating Area Seawater Treatment Plant. Produced water from the Lisburne Production Center was used between August of 2000 and May 2004. Conversion to seawater injection was completed in September 2004, and seawater injection continues throughout this reporting period. All producing segments (1, 2/4 and 3/5) are receiving pressure support from water injection. There were 4 active injectors in the Niakuk Pool with an average total injection rate of approximately 12,000 bwpd for the reporting period. There were four injectors completely off-line during the reporting period (NK-16, NK-17, NK-23, and NK-28). The current injection strategy is to maintain balanced voidage replacement in each segment, however current voidage is slightly less than 1.0. The producer to injector interactions are being evaluated with decreased injection to monitor production impacts in order to better evaluate depletion options. b. Voidage Balance of Produced and Injected Fluids (C.O. 329A Rule 9b) Tables 1 and 2 detail hydrocarbon production, water injection and resultant voidage data by month for the reporting period. c. Analysis of Reservoir Pressure Surveys Within the Pool (C.O. 329A Rule 9c) Table 3 shows results from the reservoir pressure surveys taken during the reporting period. The pressures in Segments 2/4, 1, and 3/ 5 are generally managed with the original reservoir pressure of approximately 4500 psi as a target/maximum, and the bubble point pressure of 4200 psi as a minimum. Niakuk Oil Pool Page 3 ASR for Apr ’20 – Mar ‘21 2. Special Monitoring: NK-43 Well (C.O. 329A Rule 9e) NK-43 is a commingled producer which produces from both the Kuparuk and Sag River reservoirs. The AOGCC approved co-mingled production in NK-43 with production allocated to each reservoir via geochemical analysis in Conservation Order 329B on December 7 , 2006. Samples were taken from NK-43 during the reporting period for geochemical analysis to confirm production allocation splits between the Sag River and Kuparuk reservoirs. The analyses showed that ~100% of oil production in NK-43 is from the Kuparuk during the reporting period. 3. Well Activity: Permanent production facilities at Niakuk were commissioned in March 1995. There have been 29 development wells drilled into the Niakuk Oil Pool through the end of the reporting period. During the reporting period, the Niakuk field focused on optimization of producers and scale management to which inhibition treatments were performed. Rate-adding non-rig interventions were performed during the reporting period. These rate-adding interventions included perforations, hot oil treatment (HOT) jobs, gas-lift work, SSSV replacements and surface component repairs. 4. Future Development Plans (C.O. 329A Rule 9f) Future development plans are discussed in the 2020 Niakuk Plan of Development filed with the Division of Oil and Gas of the Alaska Department of Natural Resources, which the commission received. The commission will be copied when the 2021 update of the Niakuk Plan of Development is filed with the Division. Niakuk Oil Pool Page 4 ASR for Apr ’20 – Mar ‘21 5. Review of Pool Production Allocation Factors (per Administrative Approval Docket Number: CO-15-013 Done January 7, 2016) LPC monthly average oil allocation factors are supplied below. The Niakuk Oil Pool and Raven Oil Pool will have the same allocation factors as LPC. Any dates with zero allocation factor were excluded. Allocation factors range from 0.88- 1.00. Daily allocation data and daily test data are being retained. Month Year LPC Allocation Factor April 2020 1.00 May 2020 0.97 June 2020 0.97 July 2020 0.97 August 2020 0.96 September 2020 0.95 October 2020 0.88 November 2020 0.97 December 2020 0.97 January 2021 0.95 February 2021 0.97 March 2021 0.98 Niakuk Oil Pool Page 5 ASR for Apr ’20 – Mar ‘21 Tables and Figures Gas Inject Water Inject MI Inject Oil Gas Water Monthly Monthly Monthly Oil Gas Date mstbo mmscf mbw mmscf mbw mmscf mstb mstb 4/1/2020 19 28 258 0 316 0 96,122 87,856 5/1/2020 19 85 190 0 336 0 96,142 87,941 6/1/2020 19 121 192 0 351 0 96,161 88,062 7/1/2020 17 58 176 0 380 0 96,177 88,120 8/1/2020 25 11 356 0 189 0 96,203 88,131 9/1/2020 23 11 357 0 0 0 96,225 88,143 10/1/2020 25 10 503 0 368 0 96,250 88,153 11/1/2020 47 19 471 0 425 0 96,297 88,172 12/1/2020 31 9 342 0 427 0 96,328 88,180 1/1/2021 25 19 268 0 380 0 96,352 88,199 2/1/2021 24 8 255 0 334 0 96,376 88,208 3/1/2021 24 4 246 0 368 0 96,400 88,212 Table 1 - Niakuk Monthly Production & Injection Volumes CumulativeMonthly Production Gas Inject Water Inject MI Inject Net Res. Oil Gas Water Monthly Monthly Monthly Voidage Date mrvb mrvb mrvb mrvb mrvb mrvb mvrb 4/1/2020 25 10 260 0 319 0 -24 5/1/2020 25 49 192 0 340 0 -74 6/1/2020 25 73 193 0 355 0 -63 7/1/2020 22 32 178 0 384 0 -153 8/1/2020 33 -4 360 0 191 0 198 9/1/2020 29 -3 361 0 0 0 387 10/1/2020 32 -5 508 0 372 0 163 11/1/2020 61 -9 475 0 430 0 98 12/1/2020 40 -9 346 0 432 0 -55 1/1/2021 32 1 271 0 384 0 -79 2/1/2021 31 -6 258 0 337 0 -54 3/1/2021 31 -8 249 0 372 0 -101 Table 2 - Niakuk Monthly Voidage Balance Monthly Production Note: Monthly Production/Injection/Voidage/Pressure data (Tables 1 & 2) do not include the production results from NK-38B, NK-14B or NK-08B wells (Raven) or injection from the NK-65A injector. They are subject to a separate Raven Oil Pool Annual Reservoir Report. Niakuk Oil Pool Page 6 ASR for Apr ’20 – Mar ‘21 Table 3 – 2020-2021 Pressure Survey Data Well Name Survey Date Pressure (psi) (Datum = 9200' SS) L5-34 4/6/2020 4118 NK-12C 2/27/2021 3260 NK-22A 5/2/2020 4023 Table 3 - Niakuk Pressure data April 1, 2020 to March 31, 2021 Point McIntyre Oil Pool Page 1 ASR for Apr ’20 – Mar ‘21 Prudhoe Bay Unit Pt. McIntyre Oil Pool 2021 Annual Reservoir Surveillance Report This Annual Reservoir Report for the period ending March 31, 2021 is submitted to the Alaska Oil and Gas Conservation Commission for the Pt. McIntyre Oil Pool in accordance with Commission regulations and Conservation Order 317B. This report covers the period between April 1, 2020 and March 31, 2021. A. Reservoir Management 1. Summary Production and injection volumes for the 12-month period ending March 31, 2021 are summarized in Table 1. Current well locations are shown in Figure 1. The dominant oil recovery mechanisms in the Pt. McIntyre Oil Pool are waterflooding and miscible gas injection in the down-structure area north of the Terrace Fault and gravity drainage in the up-structure area referred to as the Gravity Drainage (GD) Area. Gas injection commenced in the gas cap with field startup to replace voidage and promote gravity drainage. The waterflood was in continuous operation during the reporting period with 16 wells on either water injection or miscible gas injection, supporting 15 patterns (one pattern has two injectors). 2. Progress of Enhanced Recovery Project Implementation and Reservoir Management Summary (Rule 15 a) During the 12 month period from April 2020 – March 2021, a total of 17.5 BCF of MI (miscible injectant) was injected into Point McIntyre patterns. 3. Voidage Balance by Month of Produced and Injected Fluids (Rule 15 b) Monthly production and injection surface volumes are summarized in Table 1. A voidage balance of produced fluids and injected fluids for the report period is shown in Table 2. As summarized in these analyses, monthly voidage is targeted to be balanced with injection. Negative net reservoir voidage values in Table 2 indicate Injection Withdrawal Ratios greater than 1. Point McIntyre Oil Pool Page 2 ASR for Apr ’19 – Mar ‘20 4. Analysis of Reservoir Pressure Surveys within the Pool (Rule 15 c) Reservoir pressure monitoring is performed in accordance with Rule 12 of Conservation Order 317B. A summary of reservoir pressure surveys obtained during the reporting period is shown in Table 3. No pressure surveys were obtained during the reporting period as Drill Site PM1 and PM2 pad shutdowns were planned for May of 2021 to remove the bottleneck at drill site PM2 and therefore were collected during this time period to maximize production rate and have a suitable duration to obtain accurate pressure surveys. The proposed number of Pt McIntyre reservoir pressure surveys to be obtained in the coming plan year April 1 202 1 to March 31, 2022 is ten total. Eight reservoir pressure surveys are proposed for the waterflood/MI pattern dominated parts of the field and two pressure surveys are proposed for the Gravity Drainage / Gravity Drainage Water Flood Interaction (GD/GDWFI) dominated part of the field. 5. Results and Analysis of Production & Injection Logging Surveys (Rule 15 d) There were no production logs or no injection logs obtained from Pt McIntyre wells during the reporting period. Production and injection logs for the reporting period are shown in Table 4. 6. Results of Any Special Monitoring (Rule 15 e) No special monitoring was performed during the reporting period. B. Development and Production Activity 1. Well Activity There are a total of 26 well penetrations drilled from DS-PM1 including sidetracked, P&A and suspended wells. There are a total of 76 well penetrations drilled from DS-PM2. An additional water/MI injector (P1-25) is located at the West Dock staging area. During the reporting period, the scale management program continued for Pt Mac wells and included regular scale inhibition treatments. No new Pt Mac wells were put on MI for the first time. Point McIntyre Oil Pool Page 3 ASR for Apr ’19 – Mar ‘20 2. Other Activities a. Pipelines i. The P-15004 produced water injection booster pump was reinstated in February of 2021 to improve water injection rates at Point McIntyre. Additional injection rates o f 30,000-50,000 BWPD are being realized. ii. Figure 2 shows the existing pipeline configuration together with the miscible injectant distribution pipelines from LPC and CGF to the Pt. McIntyre drill sites. iii. Pt. McIntyre production is processed at LPC and GC-1. PM1 wells can only flow to the LPC. Between March of 2004 and November 2011 all wells at drill site PM2 could be flowed to either the LPC (high pressure system) or to GC-1 (low pressure system) via a 36” three phase line from PM2 to GC-1. As a result of this connection, wellhead pressures were lowered for the PM2 wells flowing to GC-1 by approximately 400 psi and utilized approximately 80 MB/D of available water handling capacity at GC-1. On November 12th 2011, the 36” line from PM2 to GC-1 was shut-in due to the integrity status of the line. Repair of the pipeline was completed October 2016, and all PM2 production now flows to GC-1, no production from PM2 flows to LPC. With reduced backpressure, increased water and gas handling capacity at GC1, and optimization of the well sorts, production from PM2 has been increased. b. Produced Water During the 12-month reporting period, the LPC continued to provide produced water for injection at Point McIntyre. Additional produced water is provided from FS1 to LPC for injection at Pt. McIntyre. c. Support Facilities Pt. McIntyre will continue to share North Slope infrastructure with the Lisburne Participating Area ("LPA") and the Initial Participating Areas to minimize duplication of facilities. 3. Future Development Plans (rule 15 f) Point McIntyre Oil Pool Page 4 ASR for Apr ’19 – Mar ‘20 Permanent production facilities at Pt. McIntyre were commissioned in 1993. There have been 97 development wells drilled into the Pt. McIntyre Oil Pool through the end of the reporting period. Future development plans are discussed in the 2020 Pt. McIntyre Plan of Development filed with the Division of Oil and Gas of the Alaska Department of Natural Resources, which the Commission. The Commission will be copied when the 2021 update of the Pt. McIntyre Plan of Development is filed with the division. Point McIntyre Oil Pool Page 5 ASR for Apr ’19 – Mar ‘20 Tables and Figures Gas Inject Water Inject MI Inject Oil Gas Water Monthly Monthly Monthly Oil Gas Date mstbo mmscf mbw mmscf mbw mmscf mstb mstb 4/1/2020 399 5,491 3,391 4,271 4,001 1444.156 480,595 1,575,732 5/1/2020 405 5,702 3,420 4,335 4,265 1034.392 481,000 1,581,434 6/1/2020 407 5,528 3,091 4,382 3,853 1542.693 481,407 1,586,962 7/1/2020 425 5,389 3,458 4,369 4,087 1484.271 481,832 1,592,351 8/1/2020 419 5,301 3,621 4,194 4,456 1313.453 482,252 1,597,652 9/1/2020 427 5,249 3,951 4,084 4,356 1257.068 482,678 1,602,901 10/1/2020 454 5,246 4,056 4,433 5,154 1679.626 483,133 1,608,148 11/1/2020 457 5,551 3,818 4,399 5,031 1426.22 483,590 1,613,699 12/1/2020 486 6,514 3,650 5,054 4,920 1595.146 484,076 1,620,213 1/1/2021 459 6,250 3,658 4,849 4,838 1406.62 484,535 1,626,463 2/1/2021 404 5,373 3,476 4,461 4,395 1554.079 484,939 1,631,836 3/1/2021 439 5,165 3,953 5,395 4,841 1822.415 485,379 1,637,000 Table 1 - Pt McIntyre Monthly Production & Injection Volumes Monthly Production Cumulative Gas Inject Water Inject MI Inject Net Res. Oil Gas Water Monthly Monthly Monthly Voidage Date mrvb mrvb mrvb mrvb mrvb mrvb mvrb 4/1/2020 554 3,540 3,442 2,914 4,061 895.37672 -334 5/1/2020 564 3,681 3,471 2,958 4,329 641.32304 -212 6/1/2020 566 3,561 3,138 2,990 3,911 956.46966 -593 7/1/2020 592 3,457 3,510 2,981 4,149 920.24802 -492 8/1/2020 583 3,400 3,675 2,862 4,523 814.34086 -541 9/1/2020 594 3,360 4,010 2,787 4,422 779.38216 -23 10/1/2020 632 3,344 4,117 3,025 5,232 1041.36812 -1,205 11/1/2020 636 3,551 3,876 3,001 5,106 884.2564 -930 12/1/2020 677 4,193 3,705 3,449 4,994 988.99052 -857 1/1/2021 639 4,026 3,713 3,308 4,911 872.1044 -713 2/1/2021 562 3,457 3,528 3,044 4,461 963.52898 -923 3/1/2021 611 3,296 4,013 3,681 4,914 1129.8973 -1,805 Table 2 - Pt McIntyre Monthly Voidage Balance Monthly Production Table 3 - Pt. McIntyre Pressure data April 1, 2020 to March 31, 2021 No pressure surveys acquired due to impending PM1 and PM2 shutdowns for removal of the PM2 bottleneck in May of 2021 Point McIntyre Oil Pool Page 6 ASR for Apr ’19 – Mar ‘20 Table 4 – Pt McIntyre Logging Comments/Interpretation No production or injection profile logs were obtained No gas cap monitoring logs were obtained Point McIntyre Oil Pool Page 7 ASR for Apr ’19 – Mar ‘20 Figure 1 Pt. McIntyre Well Location Map Unit Boundary Point McIntyre Oil Pool Page 8 ASR for Apr ’19 – Mar ‘20 PM2 Approximate Scale 0 1Miles Prudhoe Bay Existing Pipelines Pipelines for EOR PM1 LG1 L1 CCP CGF L2 L3 L5 NK L4 LPC Figure 2. Drill Site and Pipeline Configuration GC1* * GC1 location not to scale Figure 3 Raven Oil Pool Page 1 ASR for Apr ’20 – Mar ‘21 Prudhoe Bay Unit Raven Oil Pool and Sag River Undefined Oil Pool 2021 Annual Reservoir Surveillance Report This Annual Reservoir Report for the period ending March 31, 2021 is submitted to the Alaska Oil and Gas Conservation Commission for the Raven O il Pool in accordance with Commission regulations and Conservation Order 570. Data for the Sag River Undefined Oil Pool is included here as the Raven Oil Pool will eventually be expanded to encompass the Sag River Undefined Oil Pool once pool limits are defined. This report covers the period between April 1, 2020 and March 31, 2021. A. Reservoir Management 1. Summary Raven is a small oil and gas field in the Permo -Triassic interval (Ivishak and Sag River) located beneath the Niakuk Field (Kuparuk reservoir). Production from the Raven Field started in March 2001 with the completion of the Sag River in NK-43. The Sag River in NK-43 was subsequently isolated with a cast iron bridge plug (CIBP), and the well was perforated in the Kuparuk reservoir and produced until 1/2/06 when the CIBP was removed and the Sag River commingled with the Kuparuk. Production from NK-38A began in March 2005 from the Ivishak reservoir. NK-38A was sidetracked and NK-38B began production September 2016 from the optimized location. NK-14B was spudded in March 2017 and is an extension well delineating the outer boundaries of the Raven Oil Pool. The well came on production from the Sag River formation in late June, 2017 and by the middle of August had what later was determined to be a production casing leak. The well was shut-in from September, 2017 – March, 2018 to determine failure and repair options. NK -14B has since been restored to production. NK-15A was drilled and completed in March, 2018 in a position on the structure that was believed to be better situated to support and waterflood the structure for the NK - 38B offtake. Unfortunately, however, the Ivishak reservoir encountered by NK-15A was found to be wet and low permeability. In December of 2020 the Sag River formation was perforated in the NK-15A well as rich gas potential was identified and it was determined that no further utility in the Ivishak existed. After perforating, NK- 15A came online at over 1,500 BOPD. Raven Oil Pool Page 2 ASR for Apr ’20 – Mar ‘21 NK-08B was drilled and completed in April 2019 into an unswept part of Sag River formation within the Raven reservoir. The well came on production in May 2019 has been a full-time producer since that time. As NK-38B seems to exhibit aquifer support based on pressure and water analysis, NK-65A injection had been decreased to a VRR less than 1, and in May of 2020 the well was shut in for a well line repair. During this shut-in period it was determined that the support from NK-65A was not needed as the NK-15A confirmed that the Ivishak had already been swept in the fault block that NK-38B produced from. An evaluation is underway to assess the potential for NK-65A to be converted to a rich gas producer, similar to NK-15A, to maximize rate and recovery from the North and Central Raven fault blocks. The long-term depletion plan is to optimize hydrocarbon production in the Raven reservoir through voidage replacement from water injection as a supplement to aquifer influx in order to keep reservoir pressure at levels that will optimize oil recovery as well as develop up the rich gas potential that has been proven with the NK-15A. The Raven Pool voidage replacement ratio for the reporting period is deliberately less than 1.0 due the known aquifer influx influence. NK-14B production is included in voidage calculations, however as there is no connectivity with NK-65A injection rates are not managed to support NK-14B offtake. NK-14B will continue to be monitored and continued information analysis will allow for optimization of long- term depletion plans for the Sag River. 2. Analysis of Reservoir Pressure Surveys Within the Pool Static pressure surveys have been conducted on the wells in the field. Table 3 shows results of static reservoir pressure surveys conducted on the wells since March 2005. The most recent static reservoir pressure in NK-38B was taken in February 2021 and reservoir pressure was 4252 psi (datum). The proposed number of Raven reservoir pressure surveys to be obtained in the coming plan year April 1, 2021 to March 31, 2022 is two total. Hilcorp requests flexibility with specifying the two separate wells that will be surveyed while noting that Raven has a low well count. 3. Results of Production Logging, Tracer and Well Surveys No production logs were run during the reporting period. No tracer surveys were performed during the reporting period. Raven Oil Pool Page 3 ASR for Apr ’20 – Mar ‘21 B. Development and Production Activity 1. Progress of Enhanced Recovery Project Implementation and Reservoir Management Summary Waterflood at Raven began in October 2005, using water from the Initial Participating Area Seawater Treatment facilities. NK-65A is currently being evaluated for conversion to a rich gas producer, similar to NK-15A, to maximize recovery at Raven. Future development drilling to provide injection support to NK-08B and NK-14B is also currently be evaluated. 2. Voidage Balance of Produced and Injected Fluids Tables 1 and 2 detail the production, injection and calculated voidage by month for the reporting period. 3. Special Monitoring: NK-43 Well (C.O. 329A Rule 9e) NK-43 is a commingled producer which produces from both the Kuparuk and Sag River reservoirs. The AOGCC approved co-mingled production in NK-43 with production allocated to each reservoir via geochemical analysis in Conservation Order 329B on December 7, 2006. Samples were taken from NK-43 during the reporting period for geochemical analysis to confirm production allocation splits between the Sag River and Kuparuk reservoirs. The analyses showed that ~100% of oil production in NK-43 is from the Kuparuk during the reporting period. 4. Future Development Plans (C.O. 570) Permanent production facilities that Raven utilizes were commissioned in March 1995. There have been 5 development wells drilled into the Raven Oil Pool through the end of the reporting period. Future development plans are discussed in the 2020 Raven Plan of Development filed with the Division of Oil and Gas of the Alaska Department of Natural Resources, which the Commission received. The Commission will be copied when the 2021 update of the Raven Plan of Development is filed with the division. Raven Oil Pool Page 4 ASR for Apr ’20 – Mar ‘21 5. Review of Pool Production Allocation Factors (per Administrative Approval Docket Number: CO-15-013 Done January 7, 2016) LPC monthly oil average allocation factors are supplied below. The N iakuk Oil Pool and Raven Oil Pool will have the same allocation factors as LPC. Any dates with zero allocation factor were excluded. Allocation factors range from 0.88-1.00. Daily allocation data and daily test data are being retained. Month Year LPC Allocation Factor April 2020 1.00 May 2020 0.97 June 2020 0.97 July 2020 0.97 August 2020 0.96 September 2020 0.95 October 2020 0.88 November 2020 0.97 December 2020 0.97 January 2021 0.95 February 2021 0.97 March 2021 0.98 Raven Oil Pool Page 5 ASR for Apr ’20 – Mar ‘21 Tables and Figures Gas Inject Water Inject MI Inject Oil + NGL Gas Water Monthly Monthly Monthly Oil Gas Date mstbo mmscf mbw mmscf mbw mmscf mstb mstb 4/1/2020 50 152 55 0 154 0 4,830 24,898 5/1/2020 53 172 52 0 123 0 4,880 25,069 6/1/2020 42 139 45 0 0 0 4,920 25,208 7/1/2020 38 120 31 0 0 0 4,955 25,328 8/1/2020 37 102 46 0 0 0 4,991 25,430 9/1/2020 29 100 70 0 0 0 5,018 25,530 10/1/2020 25 103 96 0 0 0 5,041 25,633 11/1/2020 26 106 39 0 0 0 5,065 25,738 12/1/2020 39 244 47 0 0 0 5,101 25,982 1/1/2021 43 342 81 0 0 0 5,139 26,324 2/1/2021 44 435 67 0 0 0 5,178 26,759 3/1/2021 51 567 86 0 0 0 5,223 27,326 Table 1 - Raven Monthly Production & Injection Volumes CumulativeMonthly Production Gas Inject Water Inject MI Inject Net Res. Oil Gas Water Monthly Monthly Monthly Voidage Date mrvb mrvb mrvb mrvb mrvb mrvb mvrb 4/1/2020 72 80 56 0 156 0 52 5/1/2020 77 92 53 0 124 0 98 6/1/2020 60 76 46 0 0 0 182 7/1/2020 55 64 32 0 0 0 151 8/1/2020 55 51 47 0 0 0 152 9/1/2020 42 55 71 0 0 0 168 10/1/2020 35 61 97 0 0 0 193 11/1/2020 37 62 40 0 0 0 139 12/1/2020 55 158 48 0 0 0 261 1/1/2021 59 230 82 0 0 0 371 2/1/2021 60 301 67 0 0 0 429 3/1/2021 69 397 86 0 0 0 552 Table 2 - Raven Monthly Voidage Balance Monthly Production Note: Monthly Production/Injection/Voidage for the Ivishak and Sag River. Raven Oil Pool Page 6 ASR for Apr ’20 – Mar ‘21 Table 3 – Raven & Sag River Undefined Ivishak & Sag Pressure Survey Data Since March 2005 Sw Name Test Date Pres Surv Type Datum Ss Pres Datum NK-38A 3/29/2005 SBHP 9850 4973 NK-38A 8/1/2005 SBHP 9850 4237 NK-38A 8/7/2005 SBHP 9850 4273 NK-65A 8/9/2005 SBHP 9850 4463 NK-65A 8/15/2005 SBHP 9850 4295 NK-38A 12/24/2005 SBHP 9850 4210 NK-65A 5/24/2006 SBHP 9850 4414 NK-38A 7/26/2006 SBHP 9850 4155 NK-65A 7/26/2006 SBHP 9850 4400 NK-38A 1/23/2007 SBHP 9850 4104 NK-38A 7/6/2007 SBHP 9850 3758 NK-65A 8/16/2007 SBHP 9850 4827 NK-38A 8/24/2007 SBHP 9850 4370 NK-38A 10/30/2007 SBHP 9850 4379 NK-38A 6/9/2008 SBHP 9850 3543 NK-65A 8/17/2008 SBHP 9850 4379 NK-38A 9/2/2008 SBHP 9850 3507 NK-38A 4/29/2009 SBHP 9850 3537 NK-38A 5/18/2009 SBHP 9850 3928 NK-65A 8/8/2009 SFO 9850 4525 NK-38A 8/31/2009 SBHP 9850 4165 NK-65A 6/5/2010 SFO 9850 4534 NK-38A 7/6/2010 SBHP 9850 4090 NK-65A 6/4/2011 SBHP 9850 4468 NK-38A 6/6/2011 SBHP 9850 4402 NK-65A 6/27/2012 SFO 9850 4497 NK-38A 7/14/2012 SBHP 9850 3976 NK-65A 7/13/2013 SFO 9850 4429 NK-38A 12/26/2013 SBHP 9850 3549 NK-38A 6/26/2014 SBHP 9850 3564 Raven Oil Pool Page 7 ASR for Apr ’20 – Mar ‘21 NK-65A 7/13/2014 SFO 9850 4674 NK-43 3/12/2015 SBHP 9850 4057 NK-38A 7/31/2015 SBHP 9850 3386 NK-38A 6/3/2016 SBHP 9850 3061 NK-38B 8/21/2016 SBHP 9850 4412 NK-14B 4/27/2017 MDT -Sag 9850 4608 NK-14B 7/28/2017 SBHP - Sag 9850 3801 NK-14B 11/24/2017 SBHP- Sag 9850 4090 NK-38B 7/21/2017 SBHP 9850 4053 NK-15A 7/2/2018 SBHP 9850 4346 NK-38B 7/17/2018 SBHP 9850 4210 NK-14B 3/31/2019 PBU – Sag 9850 2454 NK-65A 10/19/2018 PBU 9850 4491 NK-08B 4/30/2019 SBHP 9850 4815 NK-38B 9/13/2019 SBHP 9850 4257 NK-38B 2/24/2021 SBHP 9850 4252