British Tullow Oil plc said Thursday it had discovered a new field in Uganda estimated to have up to 50 million barrels.
The site is located in the Victoria Nile Delta off the northeastern shore of Lake Albert, the firm's spokesman Andy Demetriou told AFP.
"Previously we were talking about 700 million confirmed barrels. I'm estimating, because the figures haven't been released yet, this well could add between 20 million and 50 million barrels," he said.
The new discovery is part of the Tullow's Ngara-1 block, which surrounds the northern tip of Lake Albert, a small fresh water lake on Uganda's border with the Democratic Republic of Congo.
Tullow has drilled 10 wells on the same site.
While the latest findings raise the confirmed figure to more than 700 million, industry watchers believe that when all exploration is finished total reserves could reach two billion barrels.