Composition Of Eocene Oil Shales In Kohat Basin, Karak, Khyber Pakhtunkhwa, Pakistan

Abstract

Kohat Basin is recognized for high quality oil shales. This study evaluates the composition of Jatta Gypsum oil shales, mainly focusing on their source rock potential. The study area is located in Nashpa village, Karak, Khyber Pakhtunkhwa, Pakistan which is the part of Kohat Basin. The shale samples were collected at surface level from the study area and were evaluated thoroughly using TOC and Rock-Eval Pyrolysis techniques which not only detected the organic matter in the samples but also indicated the producibility of the Jatta Gypsum oil shales. The results of this study categorize Jatta Gypsum oil shales as poor to fair source rock which lacks enough organic matter to be capable of producing hydrocarbons. The TOC values range from 0.02% to 0.9% indicating that these oil shales lack enough organic matter. Sample 1 and 6 are of kerogen type III and rest of the samples are of type IV kerogen indicating that sample 1 and 6 are gas prone and the remaining does not have the capability to produce hydrocarbons. Sample 1 of this study is immature, while sample 3, 4, and 6 are early-mature. This study shows that the oil shales of particular study area are of poor to fair quality, and which are mostly gas prone.