1-D basin modeling, 3-D reservoir mapping and source rock generative potential of Balkassar oilfield, Potwar basin, Pakistan

Abstract

This study presents geochemical, petrophysical and seismic interpretation and modeling data of source and reservoir rocks of Eocene and Paleocene sequences of Balkassar oilfield, Potwar Basin, Pakistan. Integrated approaches were applied to evaluate structure and various rocks i.e., Patala, Lockhart and Chorgali formations. Grid of eleven seismic lines, well logs, well tops and ten fresh rock cutting samples were used. TOC content of Patala Formation ranges between 0.25 − 1.16 wt. %, with S2 values 0.11–0.63 mg HC/g rock, thus indicating poor to fair hydrocarbon potentialwhich issupported by no distinct presence of hydrocarbon peaks in pyrolysis-GC pyrograms. Petrographic analysis showed dominant presence of vitrinitic Type III and inertinitic Type IV kerogen phytoclasts with minor amount of AOM. High abundance of reworked vitrinite and inertinite phytoclasts appear to have influenced the vitrinite reflectance data. Basin modeling predicts Lockhart Formation began oil generation at 10.30Ma age at depth 1557 m and reached peak generation at 8.43Ma age at depth 1802 m. Patala formation began oil generation at 10.56Ma age at depth 1472 m and reached its peak generation at 8.43Ma age at depth of 1768 m. 3D horizon mapping depicts that Chorgali formation is uniformly distributed and faulted from northwest corner.