Turbidite reservoirs in deepwater basins of the Brazilian equatorial margin central sector

Turbidite systems are key marine sedimentary formations found in passive continental margins, serving as major hydrocarbon reservoirs in deepwater fields worldwide. Since the 1970s, prolific hydrocarbon accumulations associated with turbidite deposits have been discovered in post-salt sequences along the Brazilian eastern margin. Recently, the margins of the Equatorial Atlantic, both in South America and Africa, have become major exploration frontiers, whose giant oil fields are found in Late Cretaceous turbidite systems. This study investigates turbidite systems in the central Brazilian Equatorial Margin using seismic data and direct hydrocarbon indicators (e.g., gas chimneys, paleo-pockmarks, flat and bright spots). These interpretations were further supported by special seismic attributes that enhance signals in both low- and high-frequency bands, improving the delineation of depositional features. The interpreted seismic patterns were also correlated with analogous responses observed in productive oil fields of the Equatorial Atlantic basins, including those of the Brazilian margin and previously studied West African basins. Three main turbidite complexes were mapped within the Brazilian oblique-transform margin segments between the St. Paul and Romanche oceanic fracture zones, encompassing the Pará–Maranhão, Barreirinhas and Ceará basins. These turbidite systems are associated with major unconformities and structurally controlled by rooted normal faults in the acoustic basement. The integration of seismic facies, attributes, and direct hydrocarbon indicators reveals strong similarities with established hydrocarbon plays in South American and African basins, achieving good chronostratigraphic alignment with the tectonic and depositional evolution of the Equatorial Atlantic margin. However, this study primarily describes potential geological risk reduction based on seismic interpretations, rather than providing definitive proof of an active petroleum system in still largely unexplored frontier basins.