Tullow Oil said that its Ngassa-2 exploration well, located in the Kaiso-Tonya region of Block 2, has struck oil and has the potential to be the largest field in the basin.

The Anglo Irish Independent said it encountered 7m of oil pay in a 14m gross sand.

Pressure data acquired through logging operations indicates the potential for a significant oil column down-dip, which could fill the entire 150km² closure, the company said.

Although evaluation is still at an early stage, with further appraisal drilling Ngassa has the potential to be the largest oil field in the basin to date, the company said in a statement.

Ngassa-2 is a deviated well drilled from the Angara spit, 3.5km from the crest of the structure, and to a total depth of 3,392m beneath the lake.

Logging, downhole pressure testing and sampling confirmed the presence of moveable oil, which has been recovered to surface.

Tullow has interests in three licences in the Lake Albert Rift Basin in Uganda. Tullow operates Block 2 with a 100% interest and has a 50% interest in Blocks 1 and 3A, which are operated by Heritage Oil (50%).