Equinor has discovered recoverable gas volumes more than twice as large as previously estimated in the Afrodite well near the Kvitebjorn field in the North Sea, the Norwegian group said on Thursday.
"We have long had faith in the Afrodite discovery, and this appraisal well has uncovered volumes far above expectations," Equinor said in a statement.
Recoverable volumes of gas and condensate are now estimated at between 77 million and 180 million barrels of oil equivalent.
Equinor will work on the possibility of a subsea development tied back to the Kvitebjorn platform.
The reservoir has relatively low permeability, which means that the gas flows slowly through the reservoir rock and makes the resources difficult to recover, Equinor said.
The results at Afrodite, which was discovered in 2008, show the potential that still exists in mature areas, it added.
Equinor operates the well and holds a 60 per cent stake, while Orlen holds 25 per cent, DNO 10 per cent and Wellesley Petroleum holds the remaining five per cent.
(Reporting by Louise Rasmussen, editing by Terje Solsvik)