2D Seismic Data Interpretation and Petrophysical Analysis of Sarasuri Area, Central Indus Basin, Pakistan

Abstract

The 2D seismic data interpretation of the Sarasuri Area was performed to get information about the subsurface geology and the geological structures present in the subsurface. With the help of seismic data interpretation exploration of hydrocarbons can be done while understanding the subsurface geology. The Area Sarasuri lies in the Central Indus basin and has an extensional regime. Three normal faults F1, F2 and F3 are marked on three seismic dip lines named GPL96-19, GPL96-4 and GPL96-46 which thus making horst and graben structure which can be seen on seismic section as well as on the contour map of the respective Formations. Time and depth contour maps have been constructed for the Sarasuri Area using key horizons which are Sui Main Limestone, Ranikot Formation and Lower Goru Formation which are reservoir Formation that has been encountered in Sara-West-01 well so to identify structural geometry such as folds, faults and stratigraphic traps that may influence the presence and movement of hydrocarbons and used for pinpointing optimal drilling locations and assessing the potential reservoir capacity within the Sarasuri Area. To calculate the hydrocarbon saturation petrophysical analysis was conducted on Lower Goru Formation and Pariwar Formation which was encountered in Sara-West-01 well. In which there was no zone identified with in Lower Goru Formation, so the whole Formation was taken as zone in which average values of the volume of shale, saturation of hydrocarbon and effective porosity in this zone was 68.94%, 2.50%, and 4.20% respectively. Whereas four hydrocarbon-bearing zones were encountered in Pariwar Formation which was marked based on log trend and zone criteria. Zone 1 exhibits a shale volume of 18.7%, with hydrocarbon saturation and effective porosity percentages of 77.08% and 12.92%, respectively. Zone 2 shows a higher shale content of 24.7% accompanied by hydrocarbon saturation and effective porosity values of 73.47% and 12.07%. In Zone 3, shale constitutes 21.18% of the volume with hydrocarbon saturation and effective porosity percentages of 68.25% and 10.88%. Zone 4 contains the lowest shale content at 9.62% with hydrocarbon saturation and effective porosity values of 69.10% and 10.20%, respectively. The analysis indicates that Zone 1 exhibits the highest hydrocarbon saturation and effective porosity compared to the other zones, suggesting it holds greater potential for hydrocarbon reserves within the Pariwar Formation.