HYDROCARBON POTENTIAL OF THE UPPER CRETACEOUS COAL AND SHALE UNITS IN THE ANAMBRA BASIN, SOUTHEASTERN NIGERIA

The hydrocarbon potential of the Upper Cretaceous units (Maastrichtian Mamu Formation) of theAnambra Basin, Southeastern Nigeria was assessed by Rock-Eval pyrolysis. The total organiccarbon (TOC) values range from 0.07 to 61.42 wt. % (averaging 8.54 wt. %). The geneticpotential (GP) and hydrogen index (HI) values range from 0.05 to 332 mg HC/g rock and 40 to771 mg HC /g respectively. These values indicate that the sediments have gas and oil generatingpotential. The organic matter is predominantly gas prone (mostly type III and mixed type III/II).The level of thermal maturity deduced from the production index (0.02 to 0.63), calculatedvitrinite reflectance of 0.47 to 0.78 %Ro and Tmax values between 338 and 441oC suggest that thecoal and shale samples are thermally immature to marginally mature with respect to petroleumgeneration.