Rovuma Geology

The Rovuma Basin, initiated with extensional shear along the Davie Ridge (probably from the early Jurassic), and developed as a rift basin from the mid Jurassic to mid-Cretaceous. North-south trending fault-bounded structures, such as the Ibo High and the Lacerda Graben are developed in the southern part of the graben, with clean shallow marine sands gas-bearing in the Cachalote-1 well and with additional reservoir potential in the Neocomian and Jurassic.

To the north the syn-rift section is buried offshore below up to 5,000 m of late Cretaceous and younger sediments of the Rovuma delta and cone. This section includes stacked high porosity deep-water channel and fan sands, particularly within the Paleocene to Oligocene, providing reservoirs for the giant gas / condensate discoveries, including Coral, Mamba / Prosperidade and Golfino-Atum. Discoveries are mainly stratigraphic, but with structural traps associated with the Palma and Mocimboa deep-water thrust belts. Within this area only eleven offshore wells have penetrated the Cretaceous, which remains largely unexplored, but with small gas discoveries reported at Tuberao-Tigre and Agulha.

Plays in the offshore Revuma Basin include Lower Tertiary and Cretaceous fan sands on the northern, southern and eastern margins of the Revuma delta cone and Tertiary to Jurassic sands in the south Revuma. In addition to stratigraphic plays, fault-bounded traps are developed in the south and along the margins of the young Kerimbas Graben. Rovuma gas may be sourced from undrilled, gas-mature Lower Cretaceous marine shales, but the presence of migrant oil in Cretaceous sands in the Ironclad-1 well and coastal seeps in the southern Rovuma, indicates a potential oil-prone petroleum system, with Lower Cretaceous, and Upper and Lower Jurassic source candidates.

Rovuma Datasets