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Home My WebLink About2020 Oooguruk-Nuiqsut Oil Pool Annual Reservoir Surveillance Report Oooguruk-Nuiqsut Oil Pool (ONOP) Oooguruk Field April 1, 2021 Eni Petroleum – Alaska Development Table of Contents SUBJECT PAGE 1.0 Progress of the Enhanced Recovery Project ................................................................................ 1 2.0 Results and Analysis of Reservoir Pressure Surveys within the Pool ........................................... 2 3.0 Results and Analysis of Production and Injection Log Surveys, Tracer Surveys, Observation Well Surveys and Any Other Special Monitoring ........................................................................ 2 4.0 Review of Pool Production Allocation Factors and Issues Over the Year ..................................... 3 5.0 Reservoir Management Summary .............................................................................................. 4 ATTACHMENTS ATTACHMENT A: ONOP Well Location Map ............................................................................................ 6 ATTACHMENT B: 2020 ONOP Voidage Balance by Month ...................................................................... 7 ATTACHMENT C: ONOP Pressure Report, Form 10-412 ........................................................................... 8 ATTACHMENT D: ONOP Reservoir Pressure Map – December, 2020 .................................................... 10 ATTACHMENT E: ONOP Annual Reservoir Properties Report, Form 10-428 .......................................... 11 Eni Petroleum – Alaska Development Page 1 1.0 Progress of the Enhanced Recovery Project The Oooguruk Field (OF) is one of two Eni US Operating Co. Inc. (Eni) offshore-operated fields in Alaska. Three oil pools, the Torok, Kuparuk and Nuiqsut are currently under development within the OF. The development consists of an offshore man-made gravel island, the Oooguruk Drillsite (ODS), located just east of the Colville River Delta in Harrison Bay. ODS production is delivered to the Oooguruk Tie-in Pad (OTP) via a buried subsea flowline bundle and onshore flowlines, metered, then transferred to Kuparuk River Unit (KRU) facilities, operated by ConocoPhillips Alaska, Inc. (CPAI), for final processing and transportation to the sales line. During 2020 low crude oil prices, lack of demand for oil, and the logistical interference of the COVID-19 pandemic resulted in budget cuts, production curtailments and project deferrals. At the end of 2020, there were 28 active Oooguruk-Nuiqsut Oil Pool (ONOP) development wells, including 18 producer and ten injection wells. One producing well, ODSN-29 Nuiqsut, remains shut-in as it is isolated in the ODSN-29 wellbore, to allow production of the Kuparuk interval. Commingling is not currently allowed nor functional at this time. The locations of the ONOP, the existing and planned ONOP wells, the current OU, and Oooguruk Nuiqsut Participating Area (ONPA) are shown in Attachment A. The Oooguruk project originally envisioned producing wells would ultimately utilize ESP completions in order to maximize drawdown and minimize gas lift and the associated KRU and hydraulic back-out effects. However, currently all producing wells, except one cycled pre- produced injector, ODSN-10, require gas lift to produce. Gas lift capacity is limited to approximately 15 MMSCFPD. The high gas lift rate coupled with approximately 10 MMSCFPD in OF formation gas increases the flowline pressure, reducing overall flowrates, and generates significant back-out cost at KRU, which is primarily constrained by gas compression capacity. These constraints result in backing out KRU fluid production when high total gas oil ratio (TGOR, includes formation and lift gas) OF fluids enter the system. Because of the hydraulic effects and KRU back-out all OF wells cannot be produced concurrently using gas lift. In 2020, on average, twelve of the 23 producing OF wells were on-line with TGOR ranking typically used to determine which wells to produce. In 2019 and early 2020 Eni initiated rig repairs, maintenance and material purchases in preparation for planned OF workover and drilling programs. However, due to low crude oil prices, the reduced demand for oil, and the logistical interference of the COVID-19 pandemic no rig workovers nor new drilling were conducted at the OF in 2020. Future ESP recompletions have been planned but have not been approved. A Partial Gas Processing (PGP) study has been initiated to determine the feasibility of installing on-site gas processing and compression equipment at OTP to mitigate gas processing constraints and reduce associated costs from KRU CPF-3. During 2020 ONOP oil production was impacted by the Alyeska Pipeline (Alyeska) prorations due to high inventories, low crude oil prices, and reduced gas handling capacity at KRU facilities associated with their North Slope production curtailment. Annual average daily ONOP production for 2020 was 7,203 BOPD. Total oil production during 2020 was 2,636,138 barrels for a total Eni Petroleum – Alaska Development Page 2 31,857,894 barrels since ONOP start-up. The annual average producing gas oil ratio (GOR) and watercut were 1,129 SCF/STBO and 15%, respectively. The new 5-mile 12-inch seawater flowline from the KRU 30-inch low pressure seawater flowline to OTP, and the Seawater Injection System (SWIS) pump upgrade project at OTP and ODS were commissioned in 2020. The system started up in May 2020 allowing higher pressure and higher rate water injection at ODS. Initially, due to a manifold integrity issue and a tubing hydrate plug in the ODSN-48 well, injection was initially limited to four ONOP wells; however, in August the hydrate was cleared and in October the manifold repairs were complete and injection is available to all active injection wells. Average daily ONOP water injection from May thru December 2020 was 7,402 BWPD with average monthly rates ranging from 559 bpd (May) to 12,935 bpd (November). Total water injection in 2020 was 1,813,552 barrels and 25,741,930 barrels since the start of injection in 2009. Gas injection was limited in 2020 due to a shutdown of one of the two OTP compressors in February preventing gas injection until it can be repaired. Consequently, total gas injection in the ONOP during 2020 was limited to 182 MMscf and 12,194 MMscf since the start of the project. Attachment B details the 2020 voidage balance for the ONOP. 2.0 Results and Analysis of Reservoir Pressure Surveys within the Pool Twenty-six pressure surveys recorded in 2020 were reported from 15 wells. The pressure survey results are summarized in the ONOP Pressure Report, Form 10-412 (See Attachment C). The ONOP Reservoir Pressure Map, Attachment D, depicts the estimated ONOP average pressures for December 2020 including shut-in and producing wells. The estimated average ONOP reservoir pressure is currently 2,300 psi at 6,350 ft. TVDss. The 2020 average annual producing GOR was 1,129 SCF/STBO and in December 2020 the GOR averaged 1,301 SCF/STBO (refer to Attachment E, Nuiqsut Annual Reservoir Properties Report Form 10-428). 3.0 Results and Analysis of Production and Injection Log Surveys, Tracer Surveys, Observation Well Surveys and Any Other Special Monitoring Reservoir surveillance is conducted to monitor wells and reservoir performance and to recommend changes in operating conditions, perform rate allocations, propose optimization actions, address, and solve general issues. Activities during the year 2020 were affected by cost and operational constraints due to the current business environment as a result of the COVID-19 pandemic. Well surveillance equipment was placed in the liners of seventeen Nuiqsut wells during the initial completions. The systems are in-place to assess production profiles and continuity along the lateral via target fluid tracers, which are monitored and analyzed by collecting surface fluid samples during restarts and over time. The tracers have been used to assess hydraulic Eni Petroleum – Alaska Development Page 3 connectivity along the laterals to evaluate the need for coil tubing interventions to clear any sand or debris blocking the flow path. For all wells, except ODSN-01A, the oil tracer components are no longer active. Monthly fluid samples are currently collected in one well, ODSN-01A. If a water breakthrough event occurs sampling to assess the water tracer response is planned. Due to budget limitations 2021 surveillance plans are limited to existing monitoring systems with possible opportunistic acquisitions associated with unplanned interventions. 4.0 Review of Pool Production Allocation Factors and Issues Over the Year Production from the Oooguruk-Torok Oil Pool (OTOP), Oooguruk-Kuparuk Oil Pool (OKOP) and Oooguruk-Nuiqsut Oil Pool (ONOP) is commingled at the surface into a common production line. Allocation between the pools is based on the ratio of total production for a pool to the total production for the Oooguruk Unit. The pool allocation factors for 2020 are: ONOP: 92.7% OKOP: 7.1% OTOP: 0.2% Theoretical production for individual wells for all pools is calculated on a daily basis. During 2020 wells were produced with chokes at 100% most of the time due to the capacity of the production line. Daily theoretical production for a well was calculated using the data from the most current well test and the amount of time a well was on production for a given day: oductionlDailyTheoreticaBOPDxDailyRate dayMinutes Minutes Welltest produced Pr)( 1440  The daily allocation factor for the unit is calculated by dividing the actual total production for the day by the sum of the theoretical daily production for each individual well. Daily allocated production is assigned to each well by multiplying its theoretical daily production by the daily allocation factor. The average daily allocation factor for 2020 was 0.9947. Eni Petroleum – Alaska Development Page 4 5.0 Reservoir Management Summary The Alaska Oil and Gas Conservation Commission (AOGCC) issued pool rules under Conservation Orders No. 645A, 596 and 597 for the OTOP, OKOP and ONOP, respectively. While there is no subsurface commingling, unitized substances produced from the three oil pools are commingled on the surface. Area injection orders (AIO) authorizing the injection of fluids for enhanced oil recovery in the OTOP, OKOP, and ONOP reservoirs were issued by the AOGCC as Area Injection Orders No. 37A, 33 and 34, respectively. Injection commenced into the ONOP in 2009. During 2020 the ONOP Under-Saturated Water-Alternating-Gas (US-WAG) reservoir management included maximizing voidage replacement and managing producing gas oil ratios by cycling producing wells on and off production where possible operationally. The current cumulative voidage replacement ratio is at 50%, which is consistent with ratio of injection wells to producing wells (18 producer and ten injection wells) and the overall ONOP pattern layout. Attachment B details the 2020 annual and cumulative voidage balance for the ONOP. In general, producing wells in the more mature flood areas have seen GOR stabilization, stabilized or increased oil production, and some water breakthrough as expected. Consistent with the water injection shutdown from July 2019 thru May 2020 the average ONOP producing GOR for 2020 was 1,129 SCF/STBO, which is slightly higher than the 1,024 SCF/STBO average GOR in 2019, and the 2020 average ONOP watercut was 15% compared to 18% in 2019. The central Kalubik fault block (Kalubik) currently has 11 wells, seven producer and four injection wells. Four producers, ODSN-01A, ODSN-25, ODSN-31, and ODSN-37 were produced consistently during 2020. Production from three wells ODSN-24, ODSN-36, and ODSN-42B was limited due to facility constraints and to manage voidage replacement and producing GORs. Kalubik 2020 average daily production was 2,429 BOPD with 501 BWPD (17%) at a 781 SCF/STBO GOR. Water and gas injection when available continued in ODSN-19i, ODSN-26i, ODSN-32i, and ODSN-34i. From June through December 2020 water injection averaged 2,734 BPD. For the 18 days of gas injection in January and February Kalubik, injection averaged 1.9 MMSCFPD. The southern Colville Delta fault block (Colville Delta) currently has nine wells, six producer and three injection wells. One producer, ODSN-16 produced consistently during 2020. Offtake from two producers ODSN-22 and ODSN-43 were restricted to manage area pressures, voidage replacement and the pattern producing GORs by alternating production cycles from the wells. Additionally, production from the ODN-10 well, a pre-produced up-dip injector, is currently cycled on for 30 days and shut-in for 60 days to manage area pressures and GORs. Due to non- competitive TGORs on gas lift, production from both ODSN-17 and ODSN-18 was limited during 2020. Colville Delta 2020 average daily production was 2,433 BOPD with 60 BWPD (2%) at a 1,587 SCF/STBO GOR. Water and gas injection when available continued in ODSN-15i, ODSN-23i, and ODSN-48i. From June through December 2020 water injection averaged 3,521 BPD. For the 38 days of gas injection in January and February Colville Delta, injection averaged 3.9 MMSCFPD. The Ivik fault block (Ivik) currently has eight wells, five producer and three injection wells. Three producers, ODSN-02, ODSN-04, and ODSN-28 were produced consistently during 2020. Eni Petroleum – Alaska Development Page 5 Production from the ODN-06 well, a pre-produced down-dip injector, due to non-competitive TGORs on gas lift, was limited during 2020. One producing well, ODSN-29 Nuiqsut, was shut-in during 2020 as it is isolated in the ODSN-29 wellbore, to allow production of the Kuparuk interval. Commingling is not currently allowed nor functional at this time. Ivik 2020 average daily production was 2,342 BOPD with 695 BWPD (23%) at a 1,026 SCF/STBO GOR. Water injection when available continued in ODSN-07i and ODSN-27i. Injection into ODSN-03i was purposely limited to assist in evaluating flow path connections in the northern area of the Ivik. From May through December 2020 water injection averaged 1,938 BPD, ranging from 317 bpd (June average) to 4,980 bpd (November average). Due to well integrity issues on gas injection in the three Ivik injection wells no gas was injected in the block. Individual well and pattern surveillance data will continue to be collected to monitor performance and improve recovery. A simulation model has been maintained and updated to assist in reservoir development and flood management decisions in the ONOP. Eni Petroleum – Alaska Development Page 6 ATTACHMENT A ONOP Well Location Map Colville Delta Fault Block Kalubik Fault Block Ivik Fault Block Eni Petroleum – Alaska Development Page 7 ATTACHMENT B 2020 ONOP Voidage Balance by Month Month Oil, MRB Free Gas, MRB Water, MRB Total Voidage, MRB Year Cum, MRB Cum since start-up, MRB 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 Cum Since Start-Up thru 2019>>63,804 Cum Since Start-Up thru 2019 >>33,339 -30,465 Jan-20 289 236 44 570 570 64,374 104 0 104 104 33,444 -466 -466 -30,930 Feb-20 257 201 51 509 1,079 64,883 40 0 40 144 33,483 -469 -935 -31,400 Mar-20 279 249 42 570 1,648 65,453 0 0 0 144 33,483 -570 -1,505 -31,970 Apr-20 240 193 38 472 2,120 65,924 0 0 0 144 33,483 -472 -1,976 -32,441 May-20 224 258 31 513 2,634 66,438 0 17 17 161 33,501 -496 -2,472 -32,937 Jun-20 265 295 37 597 3,231 67,035 0 131 131 293 33,632 -466 -2,938 -33,403 Jul-20 260 242 39 540 3,771 67,575 0 198 198 490 33,830 -342 -3,280 -33,745 Aug-20 233 235 37 505 4,276 68,080 0 187 187 677 34,016 -318 -3,599 -34,064 Sep-20 242 344 31 617 4,893 68,697 0 229 229 906 34,245 -388 -3,987 -34,452 Oct-20 250 299 43 593 5,485 69,290 0 269 269 1,175 34,514 -323 -4,310 -34,775 Nov-20 222 265 37 523 6,008 69,813 0 388 388 1,563 34,902 -135 -4,446 -34,910 Dec-20 244 306 29 579 6,588 70,392 0 395 395 1,957 35,297 -185 -4,630 -35,095 2020 Totals 3,005 3,124 459 6,588 144 1,814 1,957 -4,630 Produced Fluids Injected Fluids Net Injection Eni Petroleum – Alaska Development Page 8 ATTACHMENT C ONOP Pressure Report, Form 10-412 6. Oil Gravity: 19 - 25 8. Well Name and Number: 9. API Number 50XXXXXXXXXXXX NO DASHES 10. Type See Instructions 11. AOGCC Pool Code 12. Zone 13. Perforated Intervals Top - Bottom TVDSS 14. Final Test Date 15. Shut-In Time, Hours 16. Press. Surv. Type (see instructions for codes) 17. B.H. Temp. 18. Depth Tool TVDSS 19. Final Observed Pressure at Tool Depth 20. Datum TVDSS (input) 21. Pressure Gradient, psi/ft. 22. Pressure at Datum (cal) ODSN-25 50703206560000 O 576150 Nuiqsut 6080 - 6039 1/3/2020 5,067 SBHP 162 6,051 2,061 6,350 0.34 2,164 ODSN-36 50703205610000 O 576150 Nuiqsut 6258 - 6389 1/19/2020 4,671 SBHP 157 5,833 2,220 6,350 0.36 2,408 ODSN-22 50703207080000 O 576150 Nuiqsut 6021 - 6140 2/29/2020 695 PBU 161 5,828 1,675 6,350 0.40 1,884 ODSN-10 50703207190000 O 576150 Nuiqsut 6068 - 6111 3/13/2020 637 PBU 159 5,826 1,369 6,350 0.38 1,568 ODSN-24 50703206620000 O 576150 Nuiqsut 6218 - 6190 4/22/2020 6,926 SBHP 162 5,876 1,625 6,350 0.38 1,805 ODSN-22 50703207080000 O 576150 Nuiqsut 6021 - 6140 5/12/2020 983 PBU 161 5,828 1,701 6,350 0.40 1,910 ODSN-10 50703207190000 O 576150 Nuiqsut 6068 - 6111 5/13/2020 659 PBU 159 5,826 1,345 6,350 0.38 1,544 ODSN-03 50703206890000 WI 576150 Nuiqsut 6318 - 6336 5/16/2020 3,959 PFO 157 6,272 2,437 6,350 0.44 2,472 ODSN-02 50703206220000 O 576150 Nuiqsut 6226 - 6190 5/17/2020 394 PBU 155 5,789 1,686 6,350 0.40 1,910 ODSN-04 50703206700000 O 576150 Nuiqsut 6339 - 6307 5/18/2020 458 PBU 162 6,009 1,585 6,350 0.40 1,721 ODSN-48 50703206790000 WAG 576150 Nuiqsut 6004 - 6165 6/6/2020 2,808 PFO 150 5,851 3,690 6,350 0.15 3,765 ODSN-23 50703206390000 WAG 576150 Nuiqsut 6178 - 6555 6/8/2020 3,815 PFO 139 5,581 4,031 6,350 0.15 4,146 ODSN-27 50703206550000 WI 576150 Nuiqsut 6375 - 6237 6/17/2020 8,400 PFO 144 5,878 3,046 6,350 0.45 3,256 STATE OF ALASKA ALASKA OIL AND GAS CONSERVATION COMMISSION RESERVOIR PRESSURE REPORT 1. Operator:2. Address: 7. Gas Gravity: Oooguruk Eni US Operating Company Inc. (Eni US)3700 Centerpoint Drive, Suite 500, Anchorage, AK 99503 Oooguruk-Nuiqsut 6350 0.7 3. Unit or Lease Name:4. Field and Pool:5. Datum Reference: Eni Petroleum – Alaska Development Page 9 6. Oil Gravity: 19 - 25 8. Well Name and Number: 9. API Number 50XXXXXXXXXXXX NO DASHES 10. Type See Instructions 11. AOGCC Pool Code 12. Zone 13. Perforated Intervals Top - Bottom TVDSS 14. Final Test Date 15. Shut-In Time, Hours 16. Press. Surv. Type (see instructions for codes) 17. B.H. Temp. 18. Depth Tool TVDSS 19. Final Observed Pressure at Tool Depth 20. Datum TVDSS (input) 21. Pressure Gradient, psi/ft. 22. Pressure at Datum (cal) ODSN-42B 50703206050200 O 576150 Nuiqsut 6282 - 6466 6/18/2020 1,231 PBU 171 6,234 1,213 6,350 0.38 1,257 ODSN-48 50703206790000 WAG 576150 Nuiqsut 6004 - 6165 7/31/2020 1,224 PFO 151 5,851 3,644 6,350 0.45 3,866 ODSN-23 50703206390000 WAG 576150 Nuiqsut 6178 - 6555 8/10/2020 386 PFO 128 5,581 4,545 6,350 0.45 4,887 ODSN-27 50703206550000 WI 576150 Nuiqsut 6375 - 6237 8/10/2020 390 PFO 135 5,878 3,533 6,350 0.45 3,743 ODSN-22 50703207080000 O 576150 Nuiqsut 6021 - 6140 8/29/2020 1,241 PBU 161 5,828 1,673 6,350 0.40 1,882 ODSN-10 50703207190000 O 576150 Nuiqsut 6068 - 6111 9/14/2020 2,171 PBU 158 5,826 1,518 6,350 0.38 1,717 ODSN-07 50703207250000 WI 576150 Nuiqsut 6147 - 6246 10/13/2020 11,217 PFO 144 5,802 2,988 6,350 0.44 3,232 ODSN-26 50703206420000 WAG 576150 Nuiqsut 6056 - 6226 10/18/2020 11,353 PFO 149 5,922 3,550 6,350 0.45 3,740 ODSN-22 50703207080000 O 576150 Nuiqsut 6021 - 6140 11/1/2020 771 PBU 161 5,828 1,574 6,350 0.40 1,783 ODSN-10 50703207190000 O 576150 Nuiqsut 6068 - 6111 12/11/2020 1,358 PBU 158 5,826 1,497 6,350 0.38 1,696 ODSN-03 50703206890000 WI 576150 Nuiqsut 6318 - 6336 12/15/2020 3,731 PFO 159 6,272 2,267 6,350 0.44 2,302 ODSN-42B 50703206050200 O 576150 Nuiqsut 6282 - 6466 12/21/2020 3,833 PBU 171 6,234 1,436 6,350 0.38 1,480 ODSN-06 50703207150000 O 576150 Nuiqsut 6363 - 6492 12/21/2020 5,692 PBU 162 6,062 1,746 6,350 0.38 1,856 STATE OF ALASKA ALASKA OIL AND GAS CONSERVATION COMMISSION RESERVOIR PRESSURE REPORT 1. Operator:2. Address: Printed Name Title Date Production Engineer April 1, 2021Keith Lopez Signature 23. 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. 7. Gas Gravity: Oooguruk Eni US Operating Company Inc. (Eni US)3700 Centerpoint Drive, Suite 500, Anchorage, AK 99503 Oooguruk-Nuiqsut 6350 0.7 3. Unit or Lease Name:4. Field and Pool:5. Datum Reference: Eni Petroleum – Alaska Development Page 10 ATTACHMENT D ONOP Reservoir Pressure Map – December, 2020 Eni Petroleum – Alaska Development Page 11 ATTACHMENT E ONOP Annual Reservoir Properties Report, Form 10-428 3. Field and Pool Code: 4. Pool Name 5. Reference Datum (ft TVDSS) 6. Temperature (°F) 7. Porosity (%) 8. Permeability (md) 9. Swi (%)10. Oil Viscosity @ Original Pressure (cp) 11. Oil Viscosity @ Saturation Pressure (cp) 12. Original Pressure (psi) 13. Bubble Point or Dew Point Pressure (psi) 14. Current Reservoir Pressure (psi) 15. Oil Gravity (°API) 16. Gas Specific Gravity (Air = 1.0) 17. Gross Pay (ft) 18. Net Pay (ft)19. Original Formation Volume Factor (RB/STB) 20. Bubble Point Formation Volume Factor (RB/STB) 21. Gas Compressibility Factor (Z) 22. Original GOR (SCF/STB) 23. Current GOR (SCF/STB) 576150 Nuiqsut 6350 170 2 - 20 1 - 50 30 -60 3 - 7 3 - 7 3250 1900 2300 19 - 25 0.7 80 - 170 40 - 110 1.15 1.14 0.7 250 - 400 1301 4/1/2021Printed Name Keith Lopez Date I hereby certify that the foregoing is true and correct to the best of my knowledge. Signature Title Production Engineer STATE OF ALASKA ALASKA OIL AND GAS CONSERVATION COMMISSION ANNUAL RESERVOIR PROPERTIES REPORT 1. Operator:2. Address: Caelus Energy Alaska, LLC 3700 Centerpoint Drive, Suite 500, Anchorage AK 99503