Hilcorp: working interest owners approve no new Prudhoe IPA wells
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No new drilling at Prudhoe this year - that’s the message unit operator Hilcorp North Slope has been delivering as it files plans of development with the Alaska Division of Oil and Gas.
In January the company said the field’s working interest owners had not approved a 2021 drilling program for the Prudhoe Bay satellite fields.
In its 2021 proposed plan of development for the main Prudhoe reservoirs - the initial participating areas - dated March 30, Hilcorp delivered the same message - no new drilling in 2021.
The Prudhoe IPA message was basically the same as the Prudhoe satellite message:
“Due to the challenging economic conditions related to the COVID-19 global pandemic, the PBU working interest owners did not approve a drilling program for 2021,” Hilcorp said. “The resumption of drilling activity in 2022 will depend on market conditions and approval from working interest owners. Hilcorp North Slope will continue to evaluate drilling projects for future years.”
Drilling at the field was shut down in April 2020 due to the coronavirus pandemic.
The Prudhoe Bay unit has 254,235 acres, with average ownership of 26.36% Hilcorp, 36.4% ExxonMobil Alaska Production, 36.08% ConocoPhillips Alaska and 1.16% Chevron U.S.A.
There are 12 participating areas, including the initial participating areas, the western satellites and the Point McIntyre PA.
Proposed activitiesThe 2021 POD, covering July 1, 2021, through June 30, 2022, includes as many as 15 workovers or well completions in the IPA, Hilcorp said, drawn primarily from wells that have failed mechanically, but which could also include profile modifications or injector/producer conversions.
Hilcorp said that during the 2021 POD period it “anticipates flat to increasing well intervention activity,” with focus on maintaining existing well stock, “returning wells to service or increasing existing production through non rig rate enhancement work.”
On the facilities side, Hilcorp said it anticipates several projects:
*Seawater Treatment Plant maintenance and upgrades including inlet dredging, retrofitting cathodic protection, sea ice trenching, chemical tank reinstatement and repair and reinstatement of deaerator tower.
*At Gathering Center 2, reinstating the B slug catcher sand jetting system to improve solids and water handling capabilities.
*A turnaround at Flow Station 2 to include tank inspection, valve replacements and crude cooler install.
*Continuing the power upgrade to increase field wide power reliability.
*Pig launch/receiver valve installations for common lines 12B and 9A to improve pigging operations.
*Continued subsidence related repairs and improvements to pipelines and facilities.
Long-range activitiesUnder the category of long-range activities Hilcorp said it continues to evaluate future drilling opportunities “and plans to continue to evaluate potential undeveloped resources.”
In 2019 BP, then the Prudhoe operator, acquired new seismic data across most of the Greater Prudhoe Bay area. That 3D data was merged with the 2015 North Prudhoe Bay survey.
Hilcorp said interpretation of the recently acquired seismic would be completed prior to June 30, “and will be utilized to guide post-2021 development drilling as well as reservoir characterization and management studies.”
Hilcorp said it also plans to continue to monitor SWOP, the Sea Water Optimization Plan, performance and complete evaluation of PAVE, Pressure and Vaporization Enhancement, working toward a sanction decision for PAVE.
SWOP ends seawater injection at two Prudhoe drill sites and increases seawater injection in the gas cap (see story in Feb. 16, 2020, issue of Petroleum News titled “Fine tuning Prudhoe: Seawater injection switch to add barrels”).
2020 POD reviewIn its summary of the 2020 POD for the IPA, Hilcorp included a summary of calendar year 2020 production, which for the IPA was some 2.728 trillion cubic feet of natural gas and 60.668 million barrels of oil, for an average of 166,587 barrels per day in 2020.
The company said 798 producers and 220 injectors contributed to production or injected water and gas into the IPA.
“A focus on returning idle wells to service, optimizing production through the existing surface infrastructure and improved operational efficiency lead to an increase in fluid handling from calendar year 2019 to calendar year 2020,” Hilcorp said.
The efforts offset decline and increased the 2020 oil rate above that for 2019, with gas production for 2020 up by 422 million cubic feet per day over 2019 rates and water production up 164,000 bpd.
Alaska Oil and Gas Conservation data show Prudhoe crude oil production (for the entire field, not just the IPA) for 2020 at 78,550,002 total barrels, up by more than 2 million barrels from a 2019 total of 76,385,711 barrels.
Hilcorp said the efforts “increased IPA online well count by an average of 35 wells a day from calendar year 2019 to 2020.”
Gas cap water injection was increased significantly in 2020, with 166,000 bpd of water injected over 2019 rates. Factors contributing were facility maintenance which increased plant reliability and implementation of SWOP seawater injection in August of 2020.
“The intent of the SWOP program is to increase ultimate recovery by improving the gas vaporization process within the IPA,” Hilcorp said.
The 2020 POD drilling program saw two rotary wells drilled, a producer and an injector, and six coil tubing sidetracks, one injector and five producers.
Hilcorp said the 2020 drilling program was primarily focused on the miscible injectant sidetrack program at drill site 3.
“The 2020 rig program was successful at adding additional oil rate at the IPA,” the company said.
In April 2020 drilling activity was halted due to COVID-19 and Hilcorp said it “is not expected to resume during the remaining 2020 POD period.”
Two wells, an injector and a producer, were worked over during the 2020 POD, allowing both wells to return to service.
“Hilcorp North Slope plans to start a workover campaign in the IPA in Q2 2021,” the company said.
While well work activity was slowed in April due to COVID, Hilcorp did increase the pace of well work when it took over operatorship on July 1, with some 730 well interventions executed at Prudhoe, including all the participating areas, 461 of those jobs at the IPA. The work “included well stock sustainment, rate enhancement and well surveillance work.”
Major facility projects completed in 2020 included:
*Maintenance activities at the Sea Water Treatment Plant.
*New transformer, line relays and insulators installed on the Central Power Station, Central Gathering Facility and Central Compression Plant.
*All required integrity inspections completed.
*Water injection line pig launcher replacement at drill site 14 completed.
*Compressor controller upgrades at CGF.