Subsurface Structural Interpretation and Petrophysical Analysis of Bitrism Area, Southern Indus Basin, Pakistan

Abstract

This study presents a comprehensive geophysical and petrophysical investigation of the Bitrism area located within the Lower Indus Basin, with a primary focus on hydrocarbon exploration. The seismic interpretation involved the structural mapping of key formations, including the Kirthar Limestone, Sui Main Limestone, Lower Ranikot, Upper Goru and Lower Goru Formations using 2D seismic data and synthetic seismogram correlation. The area is structurally defined by an extensional tectonic regime, evident from the presence of multiple normal faults that have resulted in horst and graben structures. These structural features serve as potential hydrocarbon traps and time-depth contour mapping further supports the identification of promising drilling prospects. Complementing the seismic analysis, petrophysical evaluation of the Lower Goru Formation, specifically from the 2928m to 2934m depth interval, indicates moderate reservoir quality. The zone exhibits a shale volume of 10.77%, effective porosity of 8.95%, and hydrocarbon saturation of 20.94%. Despite a relatively high water saturation, the integration of geological and petrophysical parameters confirms the presence of viable hydrocarbon accumulations. Overall, the study concludes that the Bitrism area holds significant potential for future hydrocarbon development, supported by favorable subsurface structures and reservoir characteristics.