Houston independent Apache Corp. has booked two major discoveries in the UK North Sea’s Beryl area. The K and Corona wells are the first exploration prospects drilled by the operator in the Beryl region.
“Each discovery proves a separate geologic concept that helps to derisk additional drilling locations,” Apache said.
The company also has successfully drilled its Seagull prospect 50 miles south of its Forties field—the UK North Sea’s largest oil field.
K, Corona, and Seagull combined likely represent a net recoverable 50-70 MMboe, Apache said. The company’s proved reserves at yearend 2014 were 140 MMboe.
The first two exploration wells at Beryl, combined with the Seagull discovery, could increase the operator’s total North Sea reserve base by more than 50%. The company said the results obtained from these wells emphasize the quality of its seismic surveys and the accuracy of its geologic model in the Beryl area.
These discoveries come on the heels of Apache’s recent reorganization with special focus on its international and offshore assets in the North Sea, Egypt, and Gulf of Mexico (OGJ Online, June 1, 2015).
Apache provided details on five wells drilled in the region:
• In June, Apache followed up the initial K discovery well 9/19B-18 with two sidetracks into the adjacent fault blocks in the Beryl area. This discovery includes more than 1,500 ft of oil-bearing sands within the Beryl, Linnhe, Nansen, and Cormorant formations.
• The 9/18a-39A Corona exploration well, also in the Beryl area, tested Apache’s first Tertiary-aged prospect. The well was drilled to 6,411 ft (TVD) and logged 225 ft net pay in reservoir-quality sandstone.
• The Beryl ACN development well, drilled from the Beryl Alpha platform, encountered 131 ft of net pay in the Nansen and 40 ft net pay in the Eiriksson formation. After a successful completion in the Nansen on Oct. 8, the well tested at a rate of 11,194 bo/d and 30.4 MMcfd.
• The Nevis Central L4S pilot well, also in the Beryl area, was drilled to 9,298 ft and encountered 114 ft of net pay in the Triassic Lewis formation. The pilot was followed by a high-angle producer that yielded initial production of 45 MMcfd and 2,166 bo/d in a 30-day test. The well has been onstream since early July.
• The Seagull appraisal well was drilled 50 miles south of the Forties complex on Block 22/29c and confirmed 672 ft of net oil pay over a 1,092-ft column in Triassic-age sands. The flowed 8,700 bo/d and 16 MMcfd during tests. The company recently acquired a multi-azimuth 3D survey for this prospect and will continue further appraisal work. The company will assume operatorship of this license from Talisman Sinopec Energy UK Ltd. Later this year subject to approvals.
Apache holds a range of interest in the variety of UK North prospects:
• K Discovery. Apache is operator with 55% working interest. Shell holds the remaining 45%.
• Corona discovery. Apache holds 100% working interest.
• Beryl ACN and Nevis Central L4S. Apache holds 60.55% working interest in each with partner Shell holding the remaining 39.45%.
• Seagull discovery. Apache has 35% working interest. Partners include Talisman with 50% and Japex UK E&P Ltd. with 15%.
Apache reported in its second quarter earnings that while production decreased modestly in the North Sea, the operator drilled eight new wells in the region with 90% success rate. This included Apache’s first-ever subsea-tieback exploration will in the Beryl area.