Lukoil, the Russian private oil company, has acquired 25% of a project to develop the SL-4B-10 block in Sierra Leone waters in the Gulf of Guinea (West Africa). The asset was sold by project operator Talisman Energy (30%). the remaining 45% will be divided between Malaysia's Petronas (25%) and Britain's Prontinal Ltd (20%).

    Block SL-4B-10 is 2,200 square kilometers and reaches depths of 0.1 to 3 kilometers. The base agreement on the block was signed in 2003, and in 2009, 2D seismic surveys were conducted over more than 200 kilometers and 3D surveys on more than 1,000 square kilometers. These seismic studies revealed some potential oil-bearing layers.

    The influential Russian daily Kommersant reported that Lukoil is counting on this project fitting in well with another Sierra Leone offshore block. In 2011, the Russian company acquired a 49% stake in block SL-5-11 which Lukoil is developing with the Nigerian company Oranto (30%) and the USA's Vanco (21%).