Guinea Bissau

Location: Between Senegal and Guinea Conakry
Population: 1.7m
Capital city: Bissau
Currency: West African CFA Franc
Official language: Portuguese
President: José Mario Vaz  



The African Atlantic Margin which stretches for 2,500km between two tectonic plates along the coast of offshore Senegal down to Benin, is one of the exciting new geological plays opening up in West Africa. Guinea Bissau appears at a prominent place in this picture with the identification of a working petroleum system and undiscovered potential in the Casamance subbasin

Previous Exploration activities

There has been active exploration offshore Guinea Bissau since the late 1960's when Esso drilled six wells. There have been intermittent drives to promote the offshore and a number of international companies have been involved in offshore exploration during the last 40 years.

The Guinea Bissau permits are situated both in shallow and deep waters of the Casamance-Bissau subbasin within a Mesozoic-Cenozoic depocentre. Live oil recoveries from several wells drilled within the permits, and their proximity to the heavy oil accumulations at Dome Flore and Gea, support the existence of a working hydrocarbon kitchen highlighting the oil prospectivity of the Sinapa and Esperanca permits. Though very limited 3D seismic has been acquired over Sinapa prospects, the oil discovery in the Albian reservoirs brought a new dimension and optimism to the prospectivity.

Geological Setting:

The geological setting is a passive margin or marginal sag basin of Middle Jurassic to Holocene age which opens westwards from the North West African craton into the Atlantic Ocean. The tectonic history is very  long and complex which can be divided into pre rift (Upper Proterozoic to Lower Palaeozoic), synrift (Triassic to Lower Jurassic) and post rift (Middle Jurassic to Holocene) stages of basin development.

The most striking element of the petroleum system is the source rock distribution. The richness of the organic matter and the maturity is highest close to Guinea Bissau as compared to other surrounding provinces. Good quality reservoir facies and trapping mechanism brings a complete petroleum system in the area. The discoveries around Guinea Bissau, especially the most recent ones in Senegal, suggest the trend for many future potential accumulations.