Petroleum Geology of Outcropping Sediments along Imiegba Road in Etsako East Local Government Area of Edo State, Southern Anambra Basin Flank, Nigeria: Inference from Sedimentology and Organic Geochemistry
A. N. Asadu *
Department of Earth Sciences, Federal University of Petroleum Resources, Effurun, Delta State, Nigeria
K. A. Ibe
Department of Chemistry, Federal University of Petroleum Resources, Effurun, Delta State, Nigeria
*Author to whom correspondence should be addressed.
Abstract
The outcropping sediments along Imiegba road have been studied using their sedimentological and organic geochemical (Total organic carbon, TOC and Soluble organic matter, SOM) parameters. A total of sixteen (16) samples were collected and analyzed for the study. Based on sedimentological and field evidences, the main lithofacies identified from the study area are sandstone, shale and claystone. The sandstones are fine to medium-grained and friable. Also the result of the textural analyses show that the sandstones are sub-rounded, moderately to poorly sorted, strongly coarsely skewed and mesokurtic. The calculated permeability values ranging from 307.18-724.85 Md showed that they possess good permeability. Based on the high permeability values of the sands, the sandstones were inferred as good to excellent potentials for fluid transmission making them good reservoir for hydrocarbon.
The TOC values range from 0.17-1.42 wt.(%) with most of the samples above the threshold of 0.5 wt.% while the SOM, greater than 500ppm indicates that the shales have poor to good organic matter quantity and in adequate concentration for petroleum generation if other factors are suitable.
Keywords: Geochemistry, permeability, porosity, sedimentology, sandstone, shale, reservoir