Nigeria’s Marginal Energy lands $225 million Sierra Leone offshore deal 

Marginal Energy Limited, a Nigeria-based independent oil and gas producer, is committing more than $225 million to offshore exploration in Sierra Leone, signaling renewed investor appetite for one of West Africa’s least-developed petroleum basins.

The agreement, signed with the Petroleum Directorate of Sierra Leone, grants the company exploration and production rights across five offshore blocks—G-145, G-146, G-147, G-160, and G-161, covering roughly 6,800 square kilometers.

Strategic push to revive exploration

Formalized at the Invest in African Energy conference in Paris, where Sierra Leone has been actively courting global investors ahead of a planned offshore licensing round supported by newly acquired seismic data.

The government is seeking to reposition its offshore sector after years of limited activity, betting that improved geological insights and fiscal terms will unlock commercial discoveries in its frontier basin.

Fiscal terms and state participation

Under the production-sharing framework, Sierra Leone will retain a 10% carried interest in oil projects and 5% in gas during exploration and development. The state also holds an option to increase its stake by up to 9% on a paid basis once production begins.

President Julius Maada Bio described the agreement as part of a broader strategy to ensure resource development translates into tangible economic benefits, according to an official statement.

Marginal Energy expands beyond Nigeria

The move marks a significant step in Marginal Energy’s regional expansion strategy as it transitions from a Niger Delta-focused operator into a broader African upstream player.

Headquartered in Lagos, the company has built its portfolio on marginal field development but is increasingly targeting higher-risk, high-reward frontier assets.

The Sierra Leone project will include seismic acquisition and exploratory drilling, positioning the company to capitalize on early-mover advantage if commercial reserves are confirmed.