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Home My WebLink About2019 Oooguruk-Nuiqsut Oil PoolAnnual Reservoir Surveillance Report Oooguruk-Nuiqsut Oil Pool (ONOP) Oooguruk Field May 15th, 2020 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 ................................................................................. 3 ATTACHMENTS ATTACHMENT A: ONOP Well Location Map........................................................................ 5 ATTACHMENT B: 2019 ONOP Voidage Balance by Month.................................................. 6 ATTACHMENT C: ONOP Pressure Report, Form 10-412...................................................... 7 ATTACHMENT D: ONOP Reservoir Pressure Map – December, 2019.................................. 9 ATTACHMENT E: ONOP Annual Reservoir Properties Report, Form 10-428.......................10 Eni Petroleum – Alaska Development Page 1 1.0 Progress of the Enhanced Recovery Project Eni US Operating Co. Inc. (Eni) acquired 100% working interest ownership of the producing assets within the Oooguruk Unit (OU) on January 31, 2019; the voluntary OU contraction was approved effective June 1, 2019 and Eni was designated the operator effective August 1, 2019 following resignation of Caelus Natural Resources Alaska, LLC (Caelus) as operator. The OU was contracted to exclude southern leases. None of the contracted area was producing oil or gas. At the end of 2019, there were 28 active Oooguruk-Nuiqsut Oil Pool (ONOP) development wells, including 18 producer and ten injection wells. The locations of the existing and planned Oooguruk Nuiqsut Oil Pool (ONOP) wells, the current OU, and Oooguruk Nuiqsut Participating Area (ONPA) are shown in Attachment A. No rig workovers nor new drilling were conducted in the ONOP in 2019. However, Eni initiated rig repairs, maintenance, and material purchases in preparation for future OU workover and drilling programs. Currently all ONOP production wells rely on gas lift for artificial lift. Within the central Kalubik fault block, ODSN-01A, ODSN-31, ODSN-37 and ODSN-42B produced consistently during 2019. Production from wells ODSN-24, ODSN-25 and ODSN-36 was limited due to non-competitive total gas oil ratios (TGOR) on gas lift. Water and gas injection, if allowed, continued in ODSN-19i, ODSN-26i, ODSN-32i, and ODSN- 34i when available*. In the southern Colville Delta fault block, ODSN-16 produced consistently throughout 2019 despite a failed ESP in April 2019; the backup gas lift system has been effective and the TGOR remains competitive. The ODSN-17 ESP also failed in May 2019. Due to non-competitive total gas oil ratios on gas lift production from both ODSN-17 and ODSN- 18 was limited during 2019. Offtake from ODSN-10, ODSN-22 and ODSN-43 were restricted to manage voidage replacement and the producing GORs by alternating production cycles from the wells. Water and gas injection, if allowed, continued in ODSN- 15i, ODSN-23i and ODSN-48i when available*. Within the northern Ivik fault block, ODSN-02, ODSN-04, ODSN-06, and ODSN-28 produced consistently during 2019. ODSN-29 Nuiqsut production remained shut-in for evaluation and testing of the Kuparuk in the area from the well via a selective single completion installed in 2017. The long-term plan, which requires AOGCC approval, is to commingle production from the two pools at this location or alternate production from each zone as the Kuparuk is much more prolific and is currently at a higher pressure than the underlying Nuiqsut in the area. Ivik production was supported by water injection in wells ODSN-03i, ODSN-07i and ODSN-27i when available*. Annual average daily ONOP production during 2019 was 7,158 BOPD. Total oil production from the ONOP during 2019 was 2,612,652 barrels and is 29,221,755 barrels since field start-up thru 2019. The annual average producing GOR and watercut were 1,024 SCF/STBO and 18%, respectively. Annual average daily ONOP injection during 2019 was 6,211 BWPD and 3,166 Mscfd. Cumulative water injection in the ONOP during 2019 was 2,266,892 barrels and 23,928,378 barrels since the start of the project. Total gas injection in the ONOP during 2019 was 1,156 MMscf and 11,973 MMscf since the start of the project. When available* Eni Petroleum – Alaska Development Page 2 seawater and gas injection continued in the ONOP; water injection occurred 184 days and gas injection 284 days during the year. Attachment B details the 2019 voidage balance for the ONOP. (*Refer to Section 5 for additional information regarding seawater availability) 2.0 Results and Analysis of Reservoir Pressure Surveys within the Pool Thirty-six pressure surveys recorded between December 2018 and January 2020 were reported from 22 wells. The details of the surveys and interpretation are presented in Attachments C and D. The estimated average ONOP reservoir pressure is currently 2,620 psi at 6,350 ft TVDss (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 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 recently been used to assess hydraulic connectivity along the laterals to evaluate the need for coil tubing interventions to clear any sand or debris blocking the flow path. The tracers will also be used, where available, to help diagnose water breakthrough in the future. Monthly samples are currently collected in five wells: ODSN-01A, ODSN-10, ODSN-22, ODSN- 28 and ODSN-43. An extended reservoir surveillance and remedial program is ongoing in the Ivik block ODSN-03i well pattern which had early water injection breakthrough in both offset producing wells, ODSN-02 and ODSN-04. In July 2016 plugs were placed in the lateral of ODSN-03i to isolate suspected thief zones and the response was monitored in the ODSN-02 and ODSN-04 wells. A thief zone was identified in ODSN-03i in 2017 and injection restored to the lateral. Remediation of the ODSN-03i thief interval using a conformance gel treatment was completed in August 2018; injection was reestablished and a coiled tubing conveyed log to assess the post-remediation change in injectivity along the lateral was conducted in April 2019. Unfortunately, due to solids plugging of the memory tools, a quantitative lateral profile was not completed. Qualitative temperature logs suggest the thief interval is taking less fluid. Eni Petroleum – Alaska Development Page 3 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 2019 are: ONOP: 86.4% OKOP: 10.8% OTOP: 2.8% Theoretical production for individual wells for all pools is calculated on a daily basis. During 2019 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 2019 was 1.0261. 5.0 Reservoir Management Summary The Alaska Oil and Gas Conservation Commission (AOGCC) issued pool rules under Conservation Orders No. 645, 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 Oooguruk-Torok, Oooguruk-Kuparuk, and Oooguruk-Nuiqsut reservoirs were issued by the AOGCC as Area Injection Orders No. 37, 33 and 34, respectively. Injection commenced into the ONOP in 2009. During 2019 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 52% which is consistent with ratio of injection wells to producing wells and the overall ONOP pattern layout. Attachment B Eni Petroleum – Alaska Development Page 4 details the 2019 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. The average ONOP producing GOR for 2019 was 1,024 SCF/STBO which is slightly lower than the 1,204 SCF/STBO GOR in 2018. The 2019 average ONOP watercut was 18%. Continued flood throughput and reliable water supply are critical to long-term ONOP recovery. Effective July 2019, KRU converted the 3-HAMI water injection line from seawater to produced water. This removed the OU seawater supply access point at DS- 3A. No seawater was injected at ODS from July 4, 2019 through December 31, 2019. Consequently, Eni moved forward with a seawater injection supply (SWIS) enhancement project. The SWIS project will bypass KRU CPF-3 and consistently supply ODS with up to 25,000 bpd of seawater, increase water injection reliability, and avoid produced water injection at ODS. SWIS pipeline and pump module components were installed in 2019, and start up is planned in May, 2020. In association with the SWIS project, water injection supply pressures will be boosted from 2,800 psi to 3,700 psi. High pressure injection testing to 3,300 psi in 2018 on four Oooguruk Nuiqust injection wells, ODSN-26i, ODSN- 27i, ODSN-32i and ODSN-34i, demonstrated an average four-fold increase in injectivity with no containment or well integrity concerns, which is consistent with historical performance and modeling. The AOGCC has confirmed increasing the pressure limit to 3,700 psi from 2,800 psi for the ONOP is consistent with AIO 34 in that the increased pressure will not fracture the confining zones or migrate injected fluids out of the approved injection stratum. Additionally, in 2018 ODSN-26i was stimulated using a coil tubing placed treatment consisting of surfactant and solvent mixtures and downhole chlorine dioxide (ClO2) generation as an oxidizing, biocide treatment to remove near wellbore plugging. Efficacy of the treatment is under evaluation, pending restart of water injection and subsequent stabilization; however, the initial results are encouraging and Eni is evaluating treating additional ONOP injection wells. 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 and flood management decisions in the ONOP. Eni Petroleum – Alaska Development Page 5 ATTACHMENT A ONOP Well Location Map Colville Delta Kalubik Fault Block Ivik Fault Block Eni Petroleum – Alaska Development Page 6 ATTACHMENT B 2019 ONOP Voidage Balance by Month Month Oil, MRB Free Gas, MRB Water, MRB Total Voidage, MRB Year Cum, MRB Cumsince start-up, MRB Gas, MRB Water, MRB Total Injection, MRB Year Cum, MRB Cum. since start-up, MRB Net Injection, MRB Year Cum, MRB Cumsince start-up, MRB Cum Since Start-Upthru2018>> 57,532 CumSince Start-Upthru2018 >> 30,157 -27,375 Jan-19 289 469 45 803 803 58,336 134 335 469 469 30,627 -334 -334 -27,709 Feb-19 252 267 43 562 1,365 58,898 83 370 452 922 31,079 -110 -444 -27,819 Mar-19 235 276 43 554 1,919 59,452 103 422 525 1,446 31,604 -29 -473 -27,848 Apr-19 192 241 52 486 2,405 59,938 115 364 479 1,926 32,083 -7 -479 -27,854 May-19 286 298 65 649 3,054 60,587 79 393 473 2,398 32,556 -176 -656 -28,031 Jun-19 222 158 61 441 3,495 61,027 87 344 431 2,829 32,987 -10 -666 -28,041 Jul-19 270 229 54 553 4,049 61,581 61 39 100 2,929 33,087 -453 -1,119 -28,494 Aug-19 183 108 39 331 4,379 61,912 64 0 64 2,993 33,150 -267 -1,386 -28,761 Sep-19 282 192 49 522 4,901 62,433 98 0 98 3,091 33,248 -424 -1,810 -29,185 Oct-19 249 117 51 418 5,319 62,851 41 0 41 3,132 33,289 -377 -2,187 -29,562 Nov-19 270 217 44 530 5,849 63,382 0 0 0 3,132 33,289 -530 -2,717 -30,092 Dec-19 248 130 45 423 6,272 63,804 50 0 50 3,182 33,339 -373 -3,090 -30,465 2019 Totals 2,978 2,702 592 6,272 915 2,267 3,182 -3,090 Produced Fluids Injected Fluids Net Injection Eni Petroleum – Alaska Development Page 7 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-01A 50703206480100 O 576150 Nuiqsut 6153 - 6232 8/17/2019 217 PBU 164 5,989 1,240 6,350 0.40 1,384 ODSN-02 50703206220000 O 576150 Nuiqsut 6226 - 6190 8/18/2019 240 PBU 156 5,789 1,792 6,350 0.40 2,016 ODSN-03 50703206890000 WI 576150 Nuiqsut 6318 - 6336 12/15/2019 3,959 PFO 154 6,272 2,600 6,350 0.44 2,635 ODSN-04 50703206700000 O 576150 Nuiqsut 6339 - 6307 8/18/2019 240 PBU 162 6,009 1,671 6,350 0.40 1,807 ODSN-06 50703207150000 O 576150 Nuiqsut 6363 - 6492 8/19/2019 250 PBU 163 6,062 1,275 6,350 0.38 1,385 ODSN-07 50703207250000 WI 576150 Nuiqsut 6147 - 6246 12/15/2019 3,948 PFO 139 5,802 3,267 6,350 0.44 3,510 ODSN-10 50703207190000 O 576150 Nuiqsut 6068 - 6111 5/2/2019 2,228 PBU 158 5,826 1,724 6,350 0.38 1,923 ODSN-10 50703207190000 O 576150 Nuiqsut 6068 - 6111 7/1/2019 720 PBU 159 5,826 1,637 6,350 0.38 1,836 ODSN-10 50703207190000 O 576150 Nuiqsut 6068 - 6111 8/31/2019 547 PBU 159 5,826 1,487 6,350 0.38 1,686 ODSN-10 50703207190000 O 576150 Nuiqsut 6068 - 6111 10/31/2019 741 PBU 159 5,826 1,458 6,350 0.38 1,657 ODSN-10 50703207190000 O 576150 Nuiqsut 6068 - 6111 12/15/2019 346 PBU 160 5,826 1,339 6,350 0.35 1,522 ODSN-15 50703206180000 WAG 576150 Nuiqsut 6133 - 6081 11/10/2018 3,707 SBHP 150 6,136 4,542 6,350 0.44 4,637 ODSN-16 50703206200000 O 576150 Nuiqsut 6192 - 6235 5/2/2019 322 PBU 171 6,074 2,221 6,350 0.40 2,332 ODSN-16 50703206200000 O 576150 Nuiqsut 6192 - 6235 8/18/2019 240 PBU 170 6,074 2,192 6,350 0.40 2,303 ODSN-17 50703206220000 O 576150 Nuiqsut 6122 - 6305 4/29/2019 1,564 PBU 172 6,087 2,361 6,350 0.38 2,461 ODSN-22 50703207080000 O 576150 Nuiqsut 6021 - 6140 1/16/2019 981 PBU 161 5,828 1,737 6,350 0.40 1,946 ODSN-22 50703207080000 O 576150 Nuiqsut 6021 - 6140 5/2/2019 1,851 PBU 161 5,828 1,835 6,350 0.40 2,044 ODSN-22 50703207080000 O 576150 Nuiqsut 6021 - 6140 7/1/2019 719 PBU 161 5,828 1,776 6,350 0.40 1,985 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 8 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-22 50703207080000 O 576150 Nuiqsut 6021 - 6140 8/31/2019 556 PBU 161 5,828 1,691 6,350 0.40 1,900 ODSN-22 50703207080000 O 576150 Nuiqsut 6021 - 6140 10/31/2019 738 PBU 161 5,828 1,698 6,350 0.40 1,907 ODSN-22 50703207080000 O 576150 Nuiqsut 6021 - 6140 12/31/2019 742 PBU 161 5,828 1,684 6,350 0.40 1,893 ODSN-23 50703206390000 WAG 576150 Nuiqsut 6178 - 6555 12/17/2019 1,274 PFO 136 5,581 4,389 6,350 0.15 4,504 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-26 50703206420000 WAG 576150 Nuiqsut 6056 - 6226 12/15/2019 3,959 PFO 144 5,922 4,012 6,350 0.15 4,077 ODSN-27 50703206550000 WI 576150 Nuiqsut 6375 - 6237 12/15/2019 3,959 PFO 141 5,878 3,319 6,350 0.44 3,529 ODSN-28 50703206760000 O 576150 Nuiqsut 6280 - 6315 8/18/2019 237 PBU 160 5,979 1,523 6,350 0.38 1,664 ODSN-31 50703205650000 O 576150 Nuiqsut 6074 - 6263 7/27/2019 1,159 PBU 163 5,754 1,898 6,350 0.40 2,136 ODSN-32 50703205660000 WAG 576150 Nuiqsut 6161 - 6214 12/31/2019 3,718 PFO 63 -13.5 3,076 6,350 0.15 4,031 ODSN-34 50703205630000 WI 576150 Nuiqsut 6323 - 6426 12/15/2019 3,959 PFO 61 -13.5 1,910 6,350 0.40 4,455 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-42B 50703206050200 O 576150 Nuiqsut 6282 - 6466 8/18/2019 246 PBU 171 6,234 1,048 6,350 0.38 1,092 ODSN-43 50703206920000 O 576150 Nuiqsut 6085 - 6182 12/5/2018 1,680 PBU 160 5,775 2,213 6,350 0.40 2,443 ODSN-43 50703206920000 O 576150 Nuiqsut 6085 - 6182 1/30/2019 341 PBU 161 5,775 1,901 6,350 0.40 2,131 ODSN-43 50703206920000 O 576150 Nuiqsut 6085 - 6182 5/30/2019 667 SBHP 151 5,475 1,787 6,350 0.04 1,825 ODSN-48 50703206790000 WAG 576150 Nuiqsut 6004 - 6165 3/23/2019 3,367 PFO 148 5,851 3,786 6,350 0.15 3,861 ODSN-48 50703206790000 WAG 576150 Nuiqsut 6004 - 6165 12/30/2019 2,089 PFO 148 5,851 3,806 6,350 0.15 3,881 STATE OF ALASKA ALASKA OIL AND GAS CONSERVATION COMMISSION RESERVOIR PRESSURE REPORT 1. Operator: 2. Address: Printed Name Title Date Production Engineer May 1, 2020Keith 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 9 ATTACHMENT D ONOP Reservoir Pressure Map – December, 2019 Eni Petroleum – Alaska Development Page 10 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 2620 19 - 25 0.7 80 - 170 40 - 110 1.15 1.14 0.7 250 - 400 1024 5/1/2020 Printed 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