North Sea appraisal ops up the oil & gas discoveries’ projected size

September 25, 2026, by Melisa Cavcic

Three Norwegian oil and gas players – Aker BP, Equinor, and DNO – have carried out appraisal drilling activities on two hydrocarbon discoveries in the North Sea off the coast of Norway, raising the estimated size of these finds.

Deepsea Nordkapp rig; Source: Odfjell Drilling

Aker BP and its partners, Equinor and DNO, have drilled the 16/1-EA-4 H appraisal well on the Verdandi and Lillefix discoveries in the North Sea, which has increased the projected discovery size, according to the Norwegian Offshore Directorate.

The well 16/1-EA-4 H was drilled about 200 kilometers west of Stavanger by Odfjell Drilling’s Deepsea Nordkapp rig from the subsea template on the Symra field as a horizontal appraisal wellbore. This was the 11th exploration well in production license 167, which was awarded in the 13th licensing round.

The well was drilled to a vertical depth of 1,864 meters below sea level and terminated in the Heimdal Formation from the Palaeocene, with the objective of proving reservoir rocks from the Palaeocene in the Heimdal Formation and confirming the extent of the reservoir and presumed oil-water contact.

The well encountered a 14-meter gas column and a 44-meter oil column in sandstone layers in the Heimdal Formation. The gas-oil contact was encountered at 1,776 meters below sea level.

A total of 1,515 reservoir meters were drilled horizontally through the oil zone in the Heimdal Formation with moderate reservoir quality. Data acquisition has been carried out, which included obtaining fluid samples and pressure points.

While the companies presumed that the size was 0.6–1.9 million standard cubic meters of oil equivalent (4-12 million barrels) before appraisal drilling, preliminary calculations after drilling amount to 1.3–2.4 million standard cubic meters of oil equivalent (8-15 million barrels).

The water depth at the drilling site is 116 meters, and the well has been permanently plugged and abandoned. The partners are now considering the profitability and whether the discovery can potentially be tied back to the Symra field.