Shale gas prospect of different source rock types from Early Maastrichtian Mamu Formation, Anambra Basin, Nigeria

Abstract

Abstract The gas prospect of three identified source rock types from the Early Maastrichtian Mamu Formation of the Anambra Basin, Nigeria was evaluated by thermal simulation, followed by gas composition analyses of the generated hydrocarbons. The amounts of C1 and ΣC1-5 generated at the highest examined pyrolysis temperature of 480°C (Easy Ro of 3.27%) range from 3.52 to 32.00 ml/g rock and 4.08 to 43.44 ml/g rock, respectively. The sub-bituminous coal has the highest gaseous hydrocarbon generative potential up to late gas generation stage, followed by carbonaceous shale while shale has the least productive capacity. The recovery of gaseous hydrocarbons may be influenced by the ratio of TOC to clay content in all the source rocks. The gas dryness index indicates that the shale is the driest among the source rock types.