The URL can be used to link to this page

Home My WebLink About2018 Greater Point McIntyre Area Lisburne Oil Pool Page 1 ASR for Apr ’18 – Mar’19 Prudhoe Bay Unit Lisburne Oil Pool 2019 Annual Reservoir Surveillance Report This Annual Reservoir Report for the period ending March 31, 2019 is submitted to the Alaska Oil and Gas Conservation Commission for the Lisburne Oil Pool in accordance with commission regulations and Conservation Order 207C. This report covers the period from April 1, 2018 through March 31, 2019. 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, 2019 are summarized in Table 1. Oil production volumes include allocated crude oil, condensate and NGL production. 2. Reservoir Pressure Surveys W ithin the Pool A summary of reservoir pressure surveys obtained during the reporting period is shown in Table 2. 3. Results and Analysis of Production Logging Surveys There were four production logs obtained from Lisburne wells during the reporting period. Production logs for April 1, 2018 through March 31, 2019 are shown in Table 3. 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, 2019, the cumulative volume of seawater injected in L5-29 was 22,608 mbbls. The L5-29 pilot Lisburne Oil Pool Page 2 ASR for Apr ’18 – Mar’19 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 short time (48 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 BP North Slope 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 6,763 mbbls of seawater as of March 31, 2019. Seawater production has been observed in offset L3 -22. 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, 2019 the cumulative volume of seawater injected in both these wells was 9,166 mbbls. Confirmed seawater production has occurred in offset L5-16A. L5-13 developed mechanical integrity issues 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 was converted to seawater injection service in March 2013 and has injected 6,672 mbbls of seawater as of March 31, 2019. Offset producer well pressure response and seawater production have been observed. 2. Well Activity: Drilling Rig New sidetrack NK-26A was drilled and completed into the Lisburne Formation during the reporting period. Lisburne producing well L5-01 was worked over and new tubing run during the reporting period. Lisburne Oil Pool Page 3 ASR for Apr ’18 – Mar’19 3. Well Activity: Non-Rig Thirty nine Lisburne wells had a total of forty seven rate-adding non-rig interventions 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 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 liqu ids 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. 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 78 development wells in the Lisburne Oil Pool. Future development plans are discussed in the 2018 Lisburne Plan of Development filed with the Division of Oil and Gas of the Alaska Department of Natural Resource s, which the Commission received on June 20, 2018. The Commission will be copied when the 2019 update of the Lisburne Plan of Development is filed with the Division. Lisburne Oil Pool Page 4 ASR for Apr ’18 – Mar’19 Tables & Figures Table 1 - Lisburne Monthly Production & Injection Volumes Monthly Production Cumulative Production Gas Injection Water Injection Oil + NGL Gas Water Oil + NGL Gas Water Monthly Cum Monthly Cum Date mstbo mmscf mbw mstbo mmscf mbw mmscf bscf mbw mbw 4/1/2018 369.27 6,941 311 193,500 2,123,064 66,499 5,152 2,079,033 266 50,593 5/1/2018 365.645 6,655 323 193,866 2,129,719 66,822 5,110 2,084,143 280 50,873 6/1/2018 329.681 5,837 251 194,195 2,135,556 67,074 4,886 2,089,029 272 51,144 7/1/2018 295.935 4,469 299 194,491 2,140,025 67,372 2,408 2,091,438 285 51,429 8/1/2018 319.643 5,378 297 194,811 2,145,403 67,670 3,876 2,095,313 121 51,550 9/1/2018 344.931 6,163 334 195,156 2,151,566 68,004 4,402 2,099,715 61 51,611 10/1/2018 367.311 6,724 470 195,523 2,158,290 68,473 4,605 2,104,320 160 51,771 11/1/2018 390.121 7,834 375 195,913 2,166,124 68,849 4,932 2,109,252 245 52,015 12/1/2018 384.43 8,189 316 196,298 2,174,314 69,164 5,889 2,115,140 295 52,310 1/1/2019 359.996 7,605 384 196,658 2,181,919 69,548 5,870 2,121,010 715 53,026 2/1/2019 305.431 6,305 334 196,963 2,188,224 69,882 5,072 2,126,082 560 53,585 3/1/2019 379.84 7,878 354 197,343 2,196,103 70,236 6,090 2,132,172 478 54,063 Table 2 - Lisburne Pressure data April 1, 2018 to March 31, 2019 Well Name Survey Date Pressure (psi) (Datum = 8900' SS) L1-13 6/28/2018 2075 L1-31 8/6/2018 3203 L2-32 6/28/2018 3185 L3-18 6/25/2018 2789 L4-31 4/29/2018 3857 L5-17A 9/21/2018 3032 L5-21 6/29/18 3560 L5-28A 6/4/2018 3602 NK-25 10/29/2018 3367 NK-26A 5/11/2018 3027 NK-26A 6/20/2018 2825 Lisburne Oil Pool Page 5 ASR for Apr ’18 – Mar’19 Table 3 - Lisburne Logging Comments/Interpretation Production logs obtained for the following wells: L1-09 L1-27 L3-25 L5-12A Lisburne Oil Pool Page 6 ASR for Apr ’18 – Mar’19 Figure 1 - Lisburne Location and Status Map Niakuk Oil Pool Page 1 ASR for Apr ’18 – Mar ‘19 Prudhoe Bay Unit Niakuk Oil Pool 2019 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, 2018 through March 31, 2019. 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, 2019 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. 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. 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 Niakuk Oil Pool Page 2 ASR for Apr ’18 – Mar ‘19 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 are 4 active injectors in the Niakuk Pool with an average total injection rate of approximately 19,000 bwpd for the reporting period. There are three injectors currently off-line (NK-16, NK- 17 and NK-28). All three off-line injectors have well integrity issues. 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. 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. Two oil samples were taken from NK-43 during the reporting period (4/18 and 10/18) for geochemical analysis to confirm production allocation splits b etween the Sag River and Kuparuk reservoirs. The analyses showed that ~87.5% of oil production in NK-43 is from the Kuparuk during the reporting period. Niakuk Oil Pool Page 3 ASR for Apr ’18 – Mar ‘19 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 and performed numerous inhibition treatments. NK-29 and NK-27 both had tubing repair jobs that allowed for the wells to be returned to production. 4. Future Development Plans (C.O. 329A Rule 9f) Future development plans are discussed in the 2018 Niakuk Plan of Development filed with the Division of Oil and Gas of the Alaska Department of Natural Resources, which the commission received on June 20, 2018. The commission will be copied when the 2019 update of the Niakuk Plan of Development is filed with the Division. 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 0.84- 0.95. Daily allocation data and daily test data are being retained. Month Year LPC Allocation Factor April 2018 0.91 May 2018 0.93 June 2018 0.95 July 2018 0.94 August 2018 0.84 September 2018 0.90 October 2018 0.88 November 2018 0.89 December 2018 0.91 January 2019 0.93 February 2019 0.93 March 2019 0.88 Niakuk Oil Pool Page 4 ASR for Apr ’18 – Mar ‘19 Tables and Figures Table 1 - Niakuk Monthly Production & Injection Volumes Monthly Production Gas Inject Water Inject MI Inject Cumulative Oil Gas Water Monthly Monthly Monthly Oil Gas Date mstbo mmscf mbw Mmscf mbw mmscf mstb mmscf 4/1/2018 44 43 635 0 658 0 95,424 87,016 5/1/2018 43 37 598 0 708 0 95,467 87,053 6/1/2018 33 54 494 0 620 0 95,500 87,107 7/1/2018 25 35 628 0 580 0 95,524 87,142 8/1/2018 51 35 858 0 251 0 95,576 87,177 9/1/2018 45 44 624 0 136 0 95,620 87,222 10/1/2018 38 34 450 0 365 0 95,658 87,256 11/1/2018 28 37 332 0 734 0 95,686 87,293 12/1/2018 27 34 269 0 771 0 95,714 87,327 1/1/2019 31 42 300 0 809 0 95,744 87,370 2/1/2019 26 39 293 0 1,096 0 95,770 87,409 3/1/2019 16 27 183 0 731 0 95,786 87,436 Table 2 - Niakuk Monthly Voidage Balance Monthly Production Gas Inject Water Inject MI Inject Net Res. Oil Gas Water Monthly Monthly Monthly Voidage Date mrvb mrvb mrvb mrvb mrvb mrvb mvrb 4/1/2018 57 8 641 0 665 0 41 5/1/2018 55 5 604 0 715 0 -50 6/1/2018 43 22 499 0 626 0 -63 7/1/2018 32 12 634 0 586 0 92 8/1/2018 66 0 866 0 253 0 680 9/1/2018 58 9 630 0 138 0 560 10/1/2018 50 5 455 0 369 0 141 11/1/2018 36 12 335 0 741 0 -357 12/1/2018 36 10 272 0 778 0 -460 1/1/2019 40 15 303 0 817 0 -460 2/1/2019 34 14 296 0 1,106 0 -763 3/1/2019 21 11 185 0 739 0 -522 Note: Monthly Production/Injection/Voidage/Pressure data (Tables 1 & 2) do not include the production results from NK-38B nor NK-14B 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 5 ASR for Apr ’18 – Mar ‘19 Table 3 – 2018 – 2019 Pressure Survey Data Table 3 - Niakuk Pressure data April 1, 2018 to March 31, 2019 Well Name Survey Date Pressure (psi) (Datum = 9200' SS) L5-34 7/29/2018 3931 NK-08A 6/23/2018 4187 NK-09 7/18/2018 4205 NK-21 7/1/2018 5498 NK-22A 7/7/2018 3910 NK-27 7/7/2018 4090 NK-42 7/8/2018 3965 NK-61A 7/8/2018 4373 Point McIntyre Oil Pool Page 1 ASR for Apr ’18 – Mar ‘19 Prudhoe Bay Unit Pt. McIntyre Oil Pool 2019 Annual Reservoir Surveillance Report This Annual Reservoir Report for the period ending March 31, 2019 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, 2018 and March 31, 2019. A. Reservoir Management 1. Summary Production and injection volumes for the 12-month period ending March 31, 2019 are summarized in Table 1. Total Pt. McIntyre hydrocarbon liquid production (oil plus NGL) averaged 16.7 mbd. 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 ga s cap with field startup to replace voidage and promote gravity drainage. The waterflood was in continuous operation during the reporting period with 15 wells on water injection. 2. Progress of Enhanced Recovery Project Implementation and Reservoir Management Summary (Rule 15 a) During the 12 month period from April 2018 – March 2019, a total of 20.2 BCF of MI (miscible injectant) was injected into: P1-01 (2.8 BCF), P1-16 (0.2 BCF), P1-21 (3.3 BCF), P1-25 (1.8 BCF), P2-09 (1.9 BCF), P2-16 (3.1 BCF), P2-28 (2.6 BCF), P2-29 (2.5 BCF), and P2-47 (2.0 BCF). All of the fifteen waterflood patterns have had MI injection to date, although P2-34’s is very small due to well operability issues. 3. Voidage Balance by Month of Produced and Injected Fluids (Rule 15 b) Monthly production and injection surfa ce 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 ’18 – Mar ‘19 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. 5. Results and Analysis of Production & Injection Logging Surveys (Rule 15 d) There was one production log and no injection logs obtained from Pt McIntyre wells during the reporting period. Production and injection logs for April 1, 2017 thru March 31, 2018 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. P1-01 began its first bulb of MI September 2018. P1-21 began its first bulb of MI August 2018. 2. Other Activities a. Pipelines i. Figure 2 shows the existing pipeline configuration together with the miscible injectant distribution pipelines from LPC and CGF to the Pt. McIntyre drill sites. ii. 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 drillsite 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 Point McIntyre Oil Pool Page 3 ASR for Apr ’18 – Mar ‘19 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) 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 2018 Pt. McIntyre Plan of Development filed with the Division of Oil and Gas of the Alaska Department of Natural Resources, which the Commission received on June 29, 2018. The Commission will be copied when the 2019 update of the Pt. McIntyre Plan of Development is filed with the division. Point McIntyre Oil Pool Page 4 ASR for Apr ’18 – Mar ‘19 Tables and Figures Table 1 - Pt McIntyre Monthly Production & Injection Volumes Monthly Production Gas Inject Water Inject MI Inject Cumulative Oil Gas Water Monthly Monthly Monthly Oil Gas Date mstbo mmscf mbw mmscf mbw mmscf mstb mmscf 4/1/2018 447 5,624 3,328 4,411 3,114 1507.894 470,325 1,454,927 5/1/2018 481 5,442 3,525 4,540 3,771 1590.369 470,807 1,460,369 6/1/2018 410 6,003 3,254 4,236 2,531 1525.211 471,216 1,466,372 7/1/2018 470 4,457 3,717 2,311 3,538 308.235 471,686 1,470,829 8/1/2018 470 5,257 3,541 4,462 3,982 1572.745 472,156 1,476,086 9/1/2018 484 5,329 3,768 4,886 3,895 1833.73 472,640 1,481,414 10/1/2018 456 4,506 3,630 4,502 3,781 1644.687 473,095 1,485,920 11/1/2018 434 4,563 3,630 4,924 4,095 1812.803 473,529 1,490,483 12/1/2018 538 6,526 4,445 5,235 4,246 2157.028 474,067 1,497,009 1/1/2019 559 7,385 4,365 4,786 4,640 1901.373 474,626 1,504,394 2/1/2019 452 6,628 3,113 4,920 4,373 2067.553 475,079 1,511,022 3/1/2019 452 6,228 3,333 5,249 4,444 2243.276 475,531 1,517,250 Table 2 - Pt McIntyre Monthly Voidage Balance Monthly Production Gas Inject Water Inject MI Inject Net Res. Oil Gas Water Monthly Monthly Monthly Voidage Date mrvb mrvb mrvb mrvb mrvb mrvb mvrb 4/1/2018 621 3,606 3,378 3,010 3,160 934.89428 500 5/1/2018 670 3,464 3,578 3,098 3,828 986.02878 -200 6/1/2018 570 3,884 3,302 2,891 2,569 945.63082 1,351 7/1/2018 654 2,797 3,772 1,577 3,592 191.1057 1,863 8/1/2018 654 3,343 3,594 3,045 4,042 975.1019 -470 9/1/2018 673 3,385 3,825 3,334 3,953 1136.9126 -542 10/1/2018 634 2,838 3,685 3,072 3,838 1019.70594 -773 11/1/2018 603 2,889 3,684 3,360 4,157 1123.93786 -1,465 12/1/2018 749 4,174 4,511 3,572 4,310 1337.35736 214 1/1/2019 777 4,749 4,430 3,266 4,710 1178.85126 802 2/1/2019 629 4,288 3,160 3,357 4,439 1281.88286 -1,001 3/1/2019 629 4,015 3,383 3,582 4,511 1390.83112 -1,456 Point McIntyre Oil Pool Page 5 ASR for Apr ’18 – Mar ‘19 Table 3 - Pt. McIntyre Pressure data April 1, 2018 to March 31, 2019 Well Name Survey Date Pressure (psi) (Datum = 8800' SS) P2-56 6/5/2018 3,974 P2-60 6/29/2018 4,008 P2-12 7/10/2018 3,842 P2-41 2/14/2019 3,908 P2-25 2/24/2019 3,920 P2-11A 2/25/2019 3,979 P2-49 2/26/2019 3,969 P1-13 3/3/2019 3,818 P2-36A 3/4/2019 3,760 P2-48 3/5/2019 3,523 P1-07A 3/6/2019 3,635 P2-22A 3/9/2019 3,752 P2-40 3/10/2019 3,751 P1-12 3/15/2019 3,934 P1-14 3/16/2019 3,878 Table 4 – Pt McIntyre Logging Comments/Interpretation Production logs obtained for the following wells: P1-09. No gas cap monitoring logs were obtained Point McIntyre Oil Pool Page 6 ASR for Apr ’18 – Mar ‘19 Figure 1 Pt. McIntyre Well Location Map Unit Boundary Point McIntyre Oil Pool Page 7 ASR for Apr ’18 – Mar ‘19 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 ’18 – Mar ‘19 Prudhoe Bay Unit Raven Oil Pool and Sag River Undefined Oil Pool 2019 Annual Reservoir Surveillance Report This Annual Reservoir Report for the period ending March 31, 2019 is submitted to the Alaska Oil and Gas Conservation Commission for the Raven Oil 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 Underfined Oil Pool once pool limits are de fined. This report covers the period between April 1, 2018 and March 31, 2019. 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). In 2015, there were two oil wells, NK-38A (Ivishak producer) and NK-43 (commingled Kuparuk and Sag River producer), producing from the Raven Oil Pool. In August 2016, NK-38A was sidetracked into an unswept portion of the Raven field to the current NK-38B position. NK-43 has continued on comingled production during this reporting period. NK-65A has been on injection during the reporting period and a new injector was drilled but found a tight formation and was never hooked up as an injector. 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 th e 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. It is currently producing under a GOR waiver valid until August 1, 2018 and is a Tract Operation. 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. Raven Oil Pool Page 2 ASR for Apr ’18 – Mar ‘19 NK-15A was drilled and completed in March, 2018 in a position in the structure that was believed to be better situated to support and waterflood the structure for the NK-38B offtake. Unfortunately, however, the reservoir encountered by NK-15A was found to be wet and low permeability. Efforts to put NK-15A on water injection have been halted. Oil Production from the Raven pool averaged 1.10 mbd for the reporting period. As NK-38B seems to exhibit aquifer support based on pressure and water analysis, NK- 65A injection has been decreased to a VRR less than 1. 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. 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 due to connectivity uncertainly with NK- 65A injection rates are not managed to directly 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 July 2018 and reservoir pressure was 4210 psi (datum). 3. Results of Production Logging, Tracer and Well Surveys A cased hole Neutron log was obtained in NK-38B to determine the extent of any unexploited oil column remaining in the well. The log was obtained on September 11, 2018 and additional perfs were added on September 13th. B. Development and Production Activity 1. Progress of Enhanced Recovery Project Implementation and Reservoir Management Summary Raven Oil Pool Page 3 ASR for Apr ’18 – Mar ‘19 W aterflood at Raven began in October 2005, using water from the Initial Participating Area Seawater Treatment facilities. NK-65A is currently on injectio n into the Ivishak reservoir at an averag e rate of 4.1 mbw d. 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 W ell (C.O. 329A Rule 9e) NK-43 is a commingled producer which produces from both th e 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. Two oil samples were taken from NK -43 during the reporting period (4/18 and 10/18) for geochemical analysis to confirm production allocation splits between the Sag River and Kuparuk reservoirs. The analyses showed that ~87.5% 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 2018 Raven Plan of Development filed with the Division of Oil and Gas of the Alaska Department of Natural Resources, which the Commission received on June 20, 2018. The Commission will be copied when the 2019 update of the Raven Plan of Development is filed with the division. Raven Oil Pool Page 4 ASR for Apr ’18 – Mar ‘19 5. Review of Pool Production Allocation Factors (per Administrative Approva l 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 0.84-0.95. Daily allocation data and daily test data are being retained. Month Year LPC Allocation Factor April 2018 0.91 May 2018 0.93 June 2018 0.95 July 2018 0.94 TAR-21 days of production August 2018 0.84 September 2018 0.90 October 2018 0.88 November 2018 0.89 December 2018 0.91 January 2019 0.93 February 2019 0.93 March 2019 0.88 Raven Oil Pool Page 5 ASR for Apr ’18 – Mar ‘19 Tables and Figures Table 1 - Raven & Sag River Undefined Monthly Production & Injection Volumes Monthly Production Gas Inject Water Inject MI Inject Cumulative Oil + NGL Gas Water Monthly Monthly Monthly Oil Gas Date mstbo mmscf mbw mmscf mbw mmscf mstb mmscf 4/1/2018 68 308 176 0 53 0 3,883 20,805 5/1/2018 48 324 211 0 55 0 3,927 21,129 6/1/2018 33 204 112 0 95 0 3,956 21,333 7/1/2018 27 198 94 0 37 0 3,981 21,530 8/1/2018 25 171 74 0 0 0 4,004 21,701 9/1/2018 38 184 125 0 0 0 4,039 21,885 10/1/2018 54 216 166 0 63 0 4,090 22,101 11/1/2018 49 231 160 0 102 0 4,136 22,332 12/1/2018 44 206 122 0 127 0 4,178 22,538 1/1/2019 43 172 120 0 116 0 4,219 22,710 2/1/2019 36 133 93 0 41 0 4,253 22,842 3/1/2019 33 121 108 0 122 0 4,284 22,963 Table 2 - Raven & Sag River Undefined Monthly Voidage Balance Monthly Production Gas Inject Water Inject MI Inject Net Res. Oil Gas Water Monthly Monthly Monthly Voidage Date mrvb mrvb mrvb mrvb mrvb mrvb mvrb 4/1/2018 98 185 178 0 54 0 407 5/1/2018 67 213 213 0 56 0 437 6/1/2018 46 132 113 0 96 0 195 7/1/2018 38 131 95 0 37 0 227 8/1/2018 34 113 74 0 0 0 221 9/1/2018 55 112 126 0 0 0 293 10/1/2018 78 125 167 0 64 0 307 11/1/2018 71 140 162 0 103 0 270 12/1/2018 64 125 123 0 128 0 184 1/1/2019 64 99 121 0 118 0 166 2/1/2019 52 75 94 0 41 0 180 3/1/2019 47 69 109 0 124 0 101 Note: Monthly Production/Injection/Voidage for the Ivishak and Sag River. Raven Oil Pool Page 6 ASR for Apr ’18 – Mar ‘19 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 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 04/27/2017 MDT -Sag 9850 4608 NK-14B 07/28/2017 SBHP - Sag 9850 3801 NK-14B 11/24/2017 SBHP- Sag 9850 4090 NK-38B 07/21/2017 SBHP 9850 4053 NK-15A 7/2/2018 SBHP 9850 4346 NK-38B 7/17/2018 SBHP 9850 4210 NK-14B NK-65A 3/31/19 10/19/2018 PBU – Sag PBU 9850 9850 2454 4491