2D Seismic Data Interpretation And Petrophysical Analysis Of Bitrism Area, Lower Indus Basin, Pakistan

Abstract

2D Seismic data interpretation and petrophysical analysis were conducted on the Bitrism Area that is located in the Khairpur district of Sindh, Pakistan. So, to get information about the subsurface geology and the geological structures present in the subsurface. For the exploration of hydrocarbons can be done while understanding the subsurface geology. The Bitrism area is situated within the Lower Indus Basin of Pakistan, characterized as an extensional regime basin that features prominent horst and graben structures. Five normal faults designated as F1 to F5 which have been identified along seismic dip lines G20017-BTM-02, G20017-BTM-03, G20017-BTM-05, G20017-BTM- 06 and G20017-BTM-07. These faults have contributed to the formation of a horst and graben structure that is evident for the accumulation of hydrocarbon. Thes faults are seen on both the seismic sections and the contour map of the reservoir formations. Time and Depth contour maps of the Bitrism Area have been meticulously constructed using key geological horizons from the Fateh-01 well including the Kirthar Limestone, Laki Formation, Lower Ranikot Formation, and Lower Goru Formation. These maps are instrumental in identifying structural features such as folds, faults, and stratigraphic traps that can impact hydrocarbon presence and movement. They are crucial tools for locating ideal drilling sites and evaluating the reservoir's capacity in the Bitrism Area. Petrophysical analysis was conducted on the Lower Goru Formation at the Fateh-01 well to evaluate its hydrocarbon potential. This analysis utilized log trends and specific criteria to identify three distinct hydrocarbon-bearing zones within the Formation. In Lower Goru Formation, Zone 1 has 53.46% shale on average, with an effective porosity of 12.03% and a hydrocarbon saturation of 45.26%. Zone 2 has 48.88% shale on average, with an effective porosity of 13.92% and a hydrocarbon saturation of 17.29%. Zone 3 has 3.82% shale on average, with an effective porosity of 10.45% and a hydrocarbon saturation of 18.52%. The analysis shows that zone 1 has the highest hydrocarbon saturation but lower effective porosity compared to zones 2 and 3. Furthermore, zone 1 has a greater shale content than zones 2 and 3 but still it may have a potential to produce hydrocarbon.