Norwegian oil and gas giant Equinor has made an oil discovery in production license 532 located on the Johan Castberg field in the Barents Sea offshore Norway.
The Norwegian company received consent from the Petroleum Safety Authority (PSA) to drill a wildcat well 7220/5-3 using the Songa Enabler drilling rig back in July.
Equinor, the operator of production license 532, has concluded the drilling of well 7220/5-3 and the well proved oil, the Norwegian Petroleum Directorate (NPD) said on Monday.
In a separate statement on Monday, Equinor said that the well in a prospect named Skruis confirmed a volume of 12-25 million recoverable barrels of oil. Skruis is the first operated exploration well drilled by Equinor this year in the Barents Sea.
The well was drilled about 8 kilometers north of the 7220/8-1 discovery well on the Johan Castberg oil field, and 225 kilometers northwest of Hammerfest.
Nick Ashton, Equinor’s senior vice president, Exploration, Norway & UK, said: “This is an important discovery. It helps to determine the size of the Johan Castberg resource base which is currently being developed. Securing resources near existing infrastructure is an important part of Equinor’s ambition and strategy on the Norwegian continental shelf.”
The NPD said that the well’s primary exploration target was to prove petroleum in reservoir rocks from the Middle Jurassic Age (the Stø and Nordmela formations). The secondary exploration target was to prove petroleum in reservoir rocks from the Early Jurassic Age (the Tubåen formation).
According to the NPD, the well encountered a total oil column of about 35 meters in the Stø formation, 30 meters of which was effective reservoir in sandstone with moderate to good reservoir quality. The oil/water contact was encountered at 1415 meters below the sea surface. Both the Stø and the Nordmela formation are a little thicker than expected. The Stø formation has about 30 meters of water-bearing sandstone below the oil/water contact, with mainly good reservoir properties. The Nordmela formation has water-bearing sandstone layers totaling more than 100 meters with moderate to good reservoir quality. In the Tubåen formation, the sandstone layers have moderate to good reservoir properties.
Potential tie-in to Johan Castberg
The directorate also stated that preliminary estimates place the size of the discovery between 2 and 4 million standard cubic meters (Sm3) of recoverable oil. The discovery will be assessed with a view towards tie-in to the Johan Castberg field. The well was not formation-tested, but extensive data acquisition and sampling have been carried out.
The Johan Castberg field is planned for start-up in 2022 and currently has full capacity up to 2026-2027. The timing of a potential development of the Skruis discovery will be adjusted to this, Equinor said.
“Through the Johan Castberg field development we open a new oil province in the Barents Sea, enabling us to tie in this type of small discoveries that will be highly attractive when the infrastructure is in place,” says Knut Gjertsen, Equinor project director for the Johan Castberg development.
Recoverable reserves in Johan Castberg are estimated at between 450-650 million barrels. The volumes from Skruis and the Kayak discovery from 2017 are not included in this estimate.
The exploration drilling in the Skruis (7220/5-3) well was started on September 27 by the Songa Enabler drilling rig. Production license PL532 Johan Castberg is located some 100 kilometers north of the Snøhvit field, with first oil scheduled for 2022. Equinor has ongoing operations on the prospect Intrepid Eagle in PL615 in the Hoop area of the Barents Sea.
The Songa Enabler semi-submersible CAT D drilling rig will now drill five production wells on the Trestakk field in the southern part of the Norwegian Sea, where Equinor is also the operator.