Equinor and its partners have agreed to spend NOK2.3 billion (about US$270 million) to pump more oil from the Gullfaks Field in the North Sea offshore Norway, the company said Jan. 15.

The plan, which was submitted to the Norwegian Petroleum Directorate (NPD), involves using water injection for pressure support and drilling seven new wells targeting the Shetland Group reservoir, which lies above the field’s main reservoir. Hopes are to improve oil recovery at the field, where production began in 1986, by 17 million barrels (MMbbl) and doing so profitably.

“Wells that can be drilled fast and at a low cost, near existing infrastructure, will be a major contributor,” said Arne Sigve Nylund, Equinor’s executive vice president for development and production, Norway.

He later added Gullfaks formations that were once challenging—due to the carbonate reservoir—are now producing with a breakeven of less than US$30 per barrel. “I find that to be a nice bonus from Gullfaks.”

In a separate news release, NPD explained that until 2013 “the understanding was that the resources in the tight limestone reservoir in Shetland/Lista over Gullfaks could not be recovered. However, new information showed that the oil can still be produced through natural fractures in the reservoir.”

The plan includes changing the Shetland/Lista reservoir’s drainage strategy from depressurisation to water injection through drilling horizontal wells from the Gullfaks facilities, the NPD said.

Since 2013, Equinor and partners Petoro (30%) and OMV (19%) have invested more than NOK1 billion in production wells in the formation, Equinor said. More than 6 MMbbl of oil have been produced from Shetland/Lista phase 1, the company said in the release.

The reservoirs being targeted as part of the new plan are 1,700 m to 2,000 m below the seabed, according to the NPD.