The company said 926 million barrels could be obtained on a net basis in the A2 and A5 blocks in the Mauritania-Senegal-Guinea-Bissau (MSGB) Basin, in which it has an 80 percent stake.
Operations are underway to prepare for drilling in late 2018, the company said in a statement.
An FAR unit signed a so-called farm-in deal with ERIN Energy Corp in March for the blocks, under which it will fund ERIN’s share of exploration costs up to $8 million.
FAR on its own is expected to bear $25 million to $30 million in exploration costs. The Gambian government approved the deal in early July.
In the region, FAR also shares Senegal’s first oil development, the deepwater SNE project, with Britain-listed Cairn Energy and Australia’s Woodside Petroleum . Production there is expected to start by 2021. (Reporting by Aaron Saldanha in Bengaluru; Editing by Joseph Radford)