The fourth phase of development at the Equinor-operated Johan Sverdrup field in the North Sea is moving toward final investment decision (FID).
Equinor said on 15 June that new volumes in the Johan Sverdrup area provide the basis for a fourth phase of development at the field on the Norwegian Continental Shelf. Equinor and its partners are maturing a subsea development plan to access those resources, which include new volumes from the Tonjer and Geitungen discoveries.
In a news release, Kjetil Hove, Equinor’s executive vice president for development and production in Norway, called the volumes important and profitable.
“By tying new resources to existing infrastructure, we can develop them quickly, with low costs and low emissions,” he said.
In February, Equinor CEO Anders Opedal said the company expected to see at least a 10% decline in production at Johan Sverdrup as the field matures. In July 2025, Equinor approved a $1.29-billion third phase of development at the field to boost crude production when it goes online in late 2027.
The development plan calls for producing hydrocarbons from Tonjer west and east as well as from Geitungen via a subsea development tied back to existing infrastructure at Johan Sverdrup.
Tonjer is located in the northernmost part of the Geitungen terrace in the Johan Sverdrup area. Oil has previously been discovered in the area, but the volumes and potential have been uncertain, Equinor said. Two appraisal wells and a sidetrack have allowed a more precise assessment of the resource base, with preliminary estimates for Tonjer and Geitungen together at between 20 million and 30 million BOE, according to the operator. Field partner Aker BP said the resource base will be further clarified through ongoing analysis.
Equinor and Aker BP said the subsea project is being advanced toward FID, with potential startup in 2029.
Johan Sverdrup is the third-largest oil field on the NCS and has expected resources of 2.7 billion BOE. The field reached first oil in April 2019. The platforms are in about 360-ft water depth.
Equinor operates the Johan Sverdrup Unit with 42.62% on behalf of partners Aker BP with 31.57%, Petoro with 17.36%, and TotalEnergies with 8.44%.