The Petroleum Agreement for SL-5-11 provides for the drilling of one exploration well before 2013.

Covering 4,022sq km, the SL-5-11 offshore block is located offshore the Republic of Sierra Leone on the shelf and continental slope of the Atlantic Ocean, and the water depth within the block ranges from 100m to 3,300m.

The company said that 2D and 3D seismic data will reveal the presence of several promising exploration prospects.

The acquisition will extend the company’s acreage position in West Africa, and is subject to customary conditions precedent, Vanco said.

Block SL-5-11 is 21% owned by Vanco, 49% by Lukoil and 30% by Oranto Petroleum.