Evaluation of organic matter in sakesar and patala formations in Southern and Northern potwar basin, Pakistan

Abstract

The investigation of organic matter contents present in Eocene-Paleocene formations of Southern and Northern Potwar Basin, part of Upper Indus Basin Pakistan was conducted using geochemical and petrological techniques. The organic carbon content of Sakesar and Patala formations were evaluated using thirty well cutting samples from two wells, and results of both wells were compared for the first time. Patala Formation is known to be one of Potwar Basin's major petroleum bearing source rocks. Both Sakesar and Patala formations samples lie in early maturity (oil window) and peak of oil generation window for hydrocarbon generation, indicated by both vitrinite reflectance VR (%Ro) and Tmax data. Sakesar and Patala formations source rock properties shows good to very good generative potential. Sakesar Formation samples showed good TOC contents, ranging from 1.36-2.3 wt%, with 1.88 wt. % mean TOC and had HI values up to 375 mg HC/g TOC, however, Patala Formation also had good to very good TOC contents ranging from 2.65-4.2 wt% in well A and 3.1-3.9 in well B, with HI values ranging between 2.4-369 mg HC/g TOC. The samples have primarily mixed Type II/III kerogen and Type III kerogen. Results show that both formations have potential to produce hydrocarbons.