Exploration for Late Cretaceous turbidites in the Equatorial African and northeast South American margins

Abstract

The Suriname–Guyana and Ghana–Ivorian Basins exhibit strong geological similarities which are of interest from a petroleum exploration point of view. These include (1) a well-developed system of Late Cretaceous erosional canyons allowing coarse-grained shallow-water clastics to enter the deep marine basin to form attractive turbidite exploration targets; (2) a broad shelf with strong longshore currents which sort and transport coarse clastics into the canyon heads; (3) an organic-rich Cenomanian–Turonian hydrocarbon source rock which is thermally mature in the centre of the basin; and (4) a series of extensional fault-networks along the shelf margin that extend upwards from the Rift Sequence into the overlying Drift Sequence and which, along with the canyon geometries, enable migrating oil and gas to accumulate in combination structural and stratigraphic traps. In June 2007, Tullow and its partners made an important discovery in offshore Ghana, at Mahogany, which subsequently became the giant Jubilee field. Tullow is currently applying the same geoscientific technologies in offshore Suriname in the search for analogous subtle combination traps.