Petrophysics based Reservoir Evaluation of the Cretaceous Lower Goru “C” Sands, Middle Indus Basin, Sindh, Pakistan

Abstract

This study demonstrates the reservoir investigation of the Cretaceous Lower Goru “C” sand interval using exploratory well data from the middle Indus basin of Sindh. The petrophysical parameters including volume of shale, effective porosity, and water saturation of the investigated reservoir interval were calculated. The shale volume calculation results in 30–35% of non-clean (shale) lithology, which is high as compared to Sawan-01 and Sawan-08 wells. The effective porosity ranges from 12–16%, while the average value of water saturation in the complete interval of “C” sand falls in the range of 50–60%. However, certain zones with relatively lower water saturation values of around 30-50% are also observed. These zones are considered better pay zones in comparison to the other intervals. A “gas effect” phenomenon observed on cross plots represents the area of neutron-density cross-over indicating the presence of lighter hydrocarbons in this reservoir zone interval.