Controls on Deepwater Sandstone Deposition in the Campos and Espirito Santo Basins of Brazil: Implications for Reservoir Prediction

Belopolsky, Andrei¹, Kevin Boyd¹, Scott Carmichael¹, Alexey Guryanov¹, Jake Hossack¹, Bob Jones¹, Julian Penge¹, Neil Piggott¹, Adam Poptani², Pat Randell¹, Alan Roberts³, Cheree Stover¹, Mark Thompson¹ (1) BP Exploration, London, United Kingdom (2) Bristol University, (3) Badley Geoscience Ltd, Hundleby, Spilsby, Lincs, United Kingdom

Late Cretaceous and Tertiary deepwater sandstone reservoirs of Campos and Espirito Santo basins contain large hydrocarbon reserves. Predicting reservoir presence and quality in the deepwater, where thick, mobile Aptian salt plays a major role in structuring the basin, is an integral part of any future exploration program.

Regional 2D and 3D seismic data sets were integrated with structural elements mapping and well data to develop a series of gross depositional environment maps. Flexural back-stripping provided an independent estimate of the gross paleo-bathymetry of the basin at various times. In addition, a study of the present day sea floor and the better imaged shallow section was conducted in order to understand the influence of regional dip and local bathymetry on sand distribution.

The structural elements of the basins have had a profound impact on the sediment dispersal patterns. The upper slope is characterised by deeply incised submarine canyons primarily controlled by regional dip. In the lower slope local salt induced bathymetry controls deposition within salt-withdrawal mini-basins. Study of the shallow section clearly demonstrates how local salt highs deflect well developed meander-form submarine channels and prevent access of sand to certain mini-basins.