The URL can be used to link to this page

Home My WebLink About2021 Thomson Oil PoolHilcorp Alaska, LLC Post Office Box 244027 Anchorage, AK 99524-4027 3800 Centerpoint Drive Suite 1400 Anchorage, AK 99503 Phone: 907/777-8486 Joleen.oshiro@hilcorp.com April 20th, 2022 Jeremy Price, Chair Alaska Oil & Gas Conservation Commission 333 W. 7th Avenue, Suite 100 Anchorage, Alaska 99501-3539 RE: Point Thomson Unit 2021 Annual Reservoir Surveillance Report Dear Commissioner Price, Hilcorp Alaska, LLC. hereby submits an Annual Reservoir Surveillance Report for the Thomson Oil Pool within the Point Thomson Unit in accordance with Rule 8 of Area Injection Order No. 38 dated August 25, 2015 and Rule 5 of the Conservation Order No. 719 dated November 9, 2015. A technical review will be scheduled with representatives from AOGCC to review the annual reservoir surveillance report in accordance with Rule 5(b) of the Conservation Order No. 719. If you have any questions or require additional information, please contact Anthony McConkey at (907) 777-8460. Sincerely, Anthony McConkey For and On Behalf of Hilcorp Alaska, LLC. Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 1 Annual Reservoir Surveillance Report – 2021 Thomson Oil Pool Point Thomson Unit Introduction This annual reservoir surveillance report is submitted to the Alaska Oil and Gas Conservation Commission by Hilcorp Alaska, LLC., Point Thomson Unit (PTU) operator, in accordance with Rule 8 of Area Injection Order No. 38 dated August 25, 2015, and Rule 5 of Conservation Order No. 719 dated November 9, 2015, for the Thomson Oil Pool within the PTU. The report covers calendar year 2021 for the Initial Production System (IPS) facility operations. Enhanced Recovery Project and Reservoir Management – Rule 8(a) & 5(a)(v),(vi) The Point Thomson IPS project produces natural gas and condensate from the Thomson Oil Pool to recover liquid condensate for sale and reinject the residue gas as the enhanced recovery mechanism (gas-cycling). Condensate is transported through the Point Thomson Export Pipeline (PTEP) for delivery to the Trans-Alaska Pipeline System common carrier pipelines. The reservoir management strategy for the Thomson Sand is to reinject cycled gas to help maintain reservoir pressure for condensate recovery and conserve the gas for future development. The IPS also provides information about gas condensate production and reservoir connectivity to assist in subsequent development plans. Reservoir Voidage Balance – Rule 8(b) & 5(a)(i) Monthly production and injection volumes and the reservoir voidage balance for the Thomson reservoir by month and cumulative through December 2021 are summarized in Table 1. Voidage replacement ratio in 2021 was 0.87, no change from 2020. The Annual Report of Injection Project, Form 10-413, is included as Table 2. Reservoir Pressure Surveys – Rule 8(c) & 5(a)(ii) Reservoir pressure monitoring is performed in accordance with Conservation Order No. 719, Rule 3. Static bottom-hole pressure measurements were collected from permanent downhole gauges and corrected to Thomson reservoir pressure datum of -12,700’ TVDSS (true vertical depth subsea). Bottom-hole pressures were taken during well drilling prior to initial production or injection, and subsequently during extended well shut in periods. In PTU-15 and PTU-16 initial reservoir pressure was recorded using wireline MDT during initial drilling in 2010. Correcting to datum, the reservoir pressure measured in both wells was ~10,100 Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 2 psi. PTU-17 initial reservoir pressure data collected while drilling on December 29, 2015 was 10,107 psi at datum. A summary of static bottom-hole pressures is shown in Table 3, Form 10-412 Reservoir Pressure Report.Table 4 is the Form 10-428 Annual Reservoir Properties Report required by 20 AAC 25.270(e). Average properties are quoted, noting that ranges for porosity, permeability and water saturation are relatively wide. Thomson Oil Pool can be characterized as a retrograde condensate reservoir which helps to explain the reported properties. A reservoir pressure map is shown in Figure 1. Analysis of pressure surveys indicates limited reservoir pressure decline. The variation from initial recorded pressure and between wells is within the expected range given temperature corrections and fluid gradient variations. Production & Injection Log Surveys – Rule 8(d) & 5(a)(iii) No production or injection log surveys were run during the reporting period. Fracture Propagation into Adjacent Confining Intervals – Rule 8(e) Downhole and surface wellhead gas injection pressures and rates for PTU-15 and PTU-16 are shown in Figures 2 and 3, respectively. For PTU-15, at an injection rate of 130MMscf/d (million standard cubic feet), injection pressure of 10,370 psi was recorded at the downhole gauge April 20, 2021. Equivalent maximum reservoir sand face pressure was 10,686 psi with an injected gas gradient. At PTU-16, a downhole injection gauge pressure of 10,868 psi was measured March 26, 2021 at an injection rate of 98MMscf/d. The corresponding maximum sand face injection pressure is 11,240 psi with an injected gas gradient. In accordance with Area Injection Order No. 38, Rule 4, gas injection pressures were maintained below 11,500 psi at the reservoir sand face. Mechanical Integrity Test (MIT) Results – Rule 8(f) Injection wells PTU-15 and PTU-16 performed and passed casing/tubing mechanical integrity tests, witnessed by the AOGCC, on September 18, 2020. The MIT’s were scheduled as required once every four years after injection is commenced and stabilized by Rule 6 of Area Injection Order No. 38. The previous PTU-15 and PTU-16 MIT’s were conducted in October of 2016. MIT passing criteria requires the inner annulus pressure to hold a minimum of 1,500 psi or 0.25 psi/ft multiplied by the packer TVD for 30 minutes with less than 10% decline and a stabilizing pressure trend.Table 5 summarizes PTU-15 and PTU-16 2020 MIT data and results. The next MIT pressure tests on PTU-15 and PTU-16 will be due in 2024. Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 3 Inner and Outer Annulus Monitoring – Rule 8(g) Casing annulus pressures of production and injection wells completed in the Thomson reservoir are monitored in accordance with Area Injection Order No. 38, Rule 5, and Conservation Order No. 719, Rule 7. Digital continuous pressure monitoring is installed on each annulus of PTU-15, PTU-16 and PTU- 17. Control room alarms are in place to notify operations of high pressure for initiation of manual bleed down intervention. An annotated summary of annulus pressure monitoring is shown in Figures 4 to 6. Special Monitoring – Rule 8(h) & 5(a)(iii) No special monitoring was undertaken during the reporting period. Pool Production Allocation – Rule 5(a)(iv) Point Thomson production is wholly allocated back to the sole producing PTU-17 well from the Thomson reservoir. Condensate liquids are metered at the custody transfer meter on Point Thomson Central Pad. Total produced gas from PTU-17 is calculated as the sum of injected gas into PTU-15 and PTU-16, lease fuel, pilot/purge and flare gas. Reservoir Surveillance Plans – Rule 8(i) Reservoir surveillance plans for next year include the collection of surface wellhead and downhole pressure and temperature data, which will be used to monitor reservoir pressure, well productivity and injectivity. Casing annulus pressures will continue to be recorded to monitor integrity of the wells. Pressure and temperature data will be complemented by well production and injection rates, together with metered condensate, gas and water volumes. The information will be used to calculate gas-condensate ratio, water cut and voidage replacement for the field. No production or injection log surveys are planned for 2022. Development Plans – Rule 8(j) & 5(a) As noted above, IPS operations will provide data and information regarding production, well and reservoir performance, and IPS facility performance to assist in evaluation of development plans. Hilcorp Alaska is currently evaluating the economic feasibility of development at the Point Thomson Unit. Hilcorp’s evaluation of future plans will be outlined in the 2022’s PTU Plan of Development (POD) to the Alaska Department of Natural Resources as conditioned by the Point Thomson Unit Letter Agreement, dated September 10, 2018. Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 4 ATTACHMENTS Table 1: Monthly Production, Injection and Voidage Balance Summary ................................................... 5 Table 2: Annual Report of Injection Project (Form 10-413) ....................................................................... 6 Table 3: Reservoir Pressure Report (Form 10-412) ................................................................................... 7 Table 4: Annual Reservoir Properties Report (Form 10-428) .................................................................... 8 Table 5: PTU-15 and PTU-16 Mechanical Integrity Test Report (Form 10-426).......................................... 9 Figure 1: Thomson Reservoir Pressure Map ........................................................................................... 10 Figure 2: PTU-15 Injection Pressure and Rate ........................................................................................ 11 Figure 3: PTU-16 Injection Pressure and Rate ........................................................................................ 12 Figure 4: PTU-15 Annulus Monitoring .................................................................................................... 13 Figure 5: PTU-16 Annulus Monitoring .................................................................................................... 14 Figure 6: PTU-17 Annulus Monitoring .................................................................................................... 15 Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 5 Table 1: Monthly Production, Injection and Voidage Balance Summary Month Condensate (STB) Water Dry Gas Production (MSCF) Dry Gas Injection (MSCF) VRR (STB)(RB/RB) Jan-21 276,549 3,437 5,071,567 4,939,609 0.87 Feb-21 235,259 2,765 4,290,159 4,163,554 0.87 Mar-21 212,243 2,508 3,830,429 3,714,769 0.87 Apr-21 239,091 3,080 4,299,160 4,183,015 0.87 May-21 289,859 3,838 5,137,732 5,015,657 0.87 Jun-21 284,016 3,745 5,030,763 4,914,953 0.87 Jul-21 292,495 3,831 5,139,966 5,022,465 0.87 Aug-21 296,820 3,861 5,204,034 5,085,010 0.87 Sep-21 285,721 3,688 5,028,253 4,915,209 0.87 Oct-21 280,496 3,513 4,909,764 4,780,364 0.87 Nov-21 256,186 3,085 4,468,364 4,340,123 0.87 Dec-21 288,793 3,553 5,092,176 4,956,452 0.87 TOTAL 3,237,528 40,904 57,502,367 56,031,180 0.87 Note:Bc = 0.999 RB / STB Bg = 0.480 RB / MSCF Bw = 1.000 RB / STB Bc = condensate formation volume factor Bg = dry gas formation volume factor Bw = water formation volume factor MSCF = thousand standard cubic feet RB = reservoir barrels STB = stock tank barrels VRR = voidage replacement ratio Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 6 Table 2: Annual Report of Injection Project (Form 10-413) Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 7 Table 3: Reservoir Pressure Report (Form 10-412) Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 8 Table 4: Annual Reservoir Properties Report (Form 10-428) Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 9 Table 5: 2020 PTU-15 and PTU-16 Mechanical Integrity Test Report (Form 10-426) Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 10 Figure 1: Thomson Reservoir Pressure Map 10053 10053 10073 10060 Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 11 Figure 2: PTU-15 Injection Pressure and Rate Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 12 Figure 3: PTU-16 Injection Pressure and Rate Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 13 Figure 4: PTU-15 Annulus Monitoring Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 14 Figure 5: PTU-16 Annulus Monitoring Hilcorp Alaska PTU Annual Reservoir Surveillance Report 2021 Page 15 Figure 6: PTU-17 Annulus Monitoring