An evaluation of Maastrichtian-Paleocene source rock interval on the western flank of Niger Delta Basin, Nigeria: Implications for hydrocarbon prospectivity

Abstract

Maastrichtian and Paleocene shales recovered from a vertical exploratory well on the western flank of Niger Delta Basin, close to the boundary of the Dahomey (Benin) Basin, were studied for their possible contribution to the hydrocarbon potential of the basin. The organic matter richness, kerogen types, and thermal maturity of the studied shale samples and implications of hydrocarbon generation potential were determined based on results of TOC/Rock-Eval analysis. The Maastrichtian and Paleocene shale samples are characterized by total organic carbon (TOC) values of up to 4.70 wt. % and S2 (hydrocarbon-generating potential) values range from 0.68 to 2.69 mgHC/g rock, indicating poor to fair source potential. The presence of type III and type IV kerogen is indicative of poor-quality organic matter that has the potential to generate gaseous hydrocarbon. This study suggests that the Maastrichtian and Paleocene source rocks on the western flank of the Niger Delta Basin are immature to early mature stage, and could not have generated a commercial amount of hydrocarbon.