Global Anoxic Events and Local Variability in Source Rock Quality: Leveraging Our Experience from Liberiabeibe

Summary Source rock prediction in frontier exploration is typically challenged by a lack of well data and samples. To overcome this limitation, several indirect approaches are integrated to predict source rock presence and quality: (1) Leveraging conjugate margins, (2) Paleo-climatic and paleo-tectonic reconstructions, and (3) Source rock depositional analogs. Six deepwater wells drilled offshore Liberia and Sierra Leone prior to Chevron’s Carmine-1 and Nighthaw-1 wells had mixed results. Although these wells provided evidence of a working petroleum system, they also highlighted hydrocarbon charge as one of the main exploration risks in the area. A dual petroleum system was confirmed by The Carmine-1 and Nighthawk-1 wells offshore Liberia. The wells also confirmed lateral variability in source rock quality was greater than originally anticipated. Integration of paleo-bathymetric reconstructions combined with seismic interpretation of depositional fairways and basin modeling can been used to predict areas of increased source rock quality and identify areas of greater prospectivity for follow-up exploration efforts.