MSGBC Basin: A Rising Frontier for Deepwater Exploration in West Africa

The MSGBC Basin-spanning Mauritania, Senegal, The Gambia, Guinea-Bissau, and Guinea-Conakry-is rapidly emerging as one of Africa's most dynamic deepwater frontiers.

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The MSGBC Basin—spanning Mauritania, Senegal, The Gambia, Guinea-Bissau, and Guinea-Conakry—is rapidly emerging as one of Africa’s most dynamic deepwater frontiers. Once viewed as a geological backwater compared to Nigeria or Angola, the basin now stands at the centre of a major offshore renaissance driven by world-class hydrocarbon finds, expanding 3D seismic coverage, and renewed participation by global energy majors.

At the heart of the MSGBC story is the Cretaceous Shelf Margin and Base-of-Slope play, formed during the breakup of Gondwana and the opening of the Central Atlantic. This tectonic evolution created a chain of highly prospective petroleum systems analogous to those across the Atlantic in the Guyana—Suriname Basin, where ExxonMobil, Chevron, and TotalEnergies have proven prolific oil provinces.

The direct geological conjugacy between the Guinea Plateau and South America’s Demerara Plateau continues to fuel exploration optimism.

Production Milestones and Emerging Deepwater Focus

The MSGBC region achieved a major milestone in 2024 with the start-up of Woodside Energy’s Sangomar oil field offshore Senegal—the country’s first commercial oil production. Meanwhile, bp’s Greater Tortue Ahmeyim (GTA) project, straddling the maritime border between Mauritania and Senegal, began delivering liquefied natural gas (LNG) in the first half of 2025. Together, Sangomar and GTA have validated the region's geological models, proving the commercial viability of the Cretaceous plays that underlie much of the basin.

Yet, despite these successes, experts note that the MSGBC’s deepwater domain remains underexplored. Much of the acreage south of Senegal—offshore The Gambia, Guinea-Bissau, and Sierra Leone—has seen only sporadic drilling, often in shallow water or under early license regimes. New data and improved imaging now promise to change that narrative.