Shares in U.K.-based independent Tullow Oil have risen 11.71 percent on news Thursday that the Hyedua 2 and Kingfisher 3 wells offshore Ghana and onshore Uganda has “substantially increased” the proven areas of their respective fields.

Hyedua 2 has intersected a 120-metre light oil column and shows the Jubilee field extends 5 km northwest of the first discovery well in the Deepwater Tano license. The Blackford Dolphin semi-submersible will now drill a Jubilee development well and test its Mahogany 1 discovery borehole.

At the Kingfisher 3 well, company boss Aidan Heavey suggested Kingfisher was now the largest light oil discovery in East Africa. The No. 3 well has yet to encounter water and has found three reservoirs at least 110 metres deep and data shows they’re pressure influences the whole of the known area. A statement said the latest Kingfisher well will now be sidetracked.

“We are entering an exciting period for Tullow's Ghanaian and Ugandan operations with four potentially transformational wells to be drilled over the next four months." Heavey said in a statement.

Meanwhile, the Eirik Raude semi-submersible is drilling the Jubilee field’s Mahogany 3 appraisal well in the West Cape Three Points licence. Results in 40 days show yet another extension of the field.

Tullow, with nearly 50 percent, operates the Deepwater Tano license, but partners include Kosmos Energy (18 percent), Anadarko Petroleum (18 percent), Sabre Oil & Gas (4 percent) and the Ghana National Petroleum Corporation (10 percent).

Tullow also operated the Jubilee field.

Tags: Anadarko Petroleum Corporation, Ghana National Petroleum Corp. (GNPC), Kosmos Energy, Tullow Oil