Abstract:
The Gupchani gas field, which is located in Pakistan's Sindh province's Nawabshah area, is thoroughly examined in this study. The gas field's location, almost 200 kilometres northeast of Karachi and 30 km east of Nawabshah, makes it strategically significant. The field's coordinates are as follows: latitude: 26°29'30.39" to 26°22'22.54"; longitude: 68°28'34.8492" to 68°41'59.6508". The study's objectives were to use seismic interpretation techniques to learn more about the Gupchani area's subsurface geology which is located in Gambat South block operated by Pakistan Petroleum Limited. To estimate the hydrocarbon saturation petrophysical techniques are utilised in order to locate probable reserves. Interpreting seismic data is essential to exploring for hydrocarbons and improving knowledge of underlying geology. Normal faults identified in the interpreted seismic sections F1, F2, F3, F4, F5 and F6 clearly demonstrate the presence of an extensional basin regime in the research area. The presence of graben and horst structures, which promote hydrocarbon buildup, is revealed by these faults. The major source rock in the research area was the Sembar Formation; Lower Goru and Chiltan formed the reservoir Formation, and Upper Goru serves as the seal rock that completes the petroleum system. Two horizons—the Lower Goru from the Cretaceous era and the Chiltan Limestone from the Jurassic period—were found on a seismic section for this investigation. For these horizons, time and depth contour maps were subsequently made. Based on log trends, a petrophysical investigation of the Lower Goru Formation found eight hydrocarbon-containing zones out of which zones 1 and 8 were the most prominent and obeyed the criteria for the paying zones. Overall, the average values of the volume of shale, effective and average porosity in all of the zones were 38%, 8%, and 13% respectively. The saturation of hydrocarbon is 60%
