An integrated geophysical study to delineate the sub surface hydrocarbon potential of Sinjhoro area, Lower Indus Basin, Pakistan

Abstract

This dissertation contains the interpretation of 2D seismic reflection data of selected seismic lines of Sinjhoro Exploration Lease (E.L.), Southern Indus Basin, Pakistan. The main objective of this Project was delineation of subsurface structure. The data comprised three seismic lines, base map and well tops of well CHAK 66-01. The names of lines obtained are (200 17-SNJ-03 200 17-SNJ-23 and 200 17-SNJ-24). Three prominent reflectors were marked on the basis of their reflection character. They represent Rani kot, Lower Goru and Basal Sands respectively. Structural analysis of the seismic data shows that this area is characterized by normal faulting. The Lower Goru formation of early to Middle Cretaceous age is the best known reservoir of the area and was of main concern. Time and Depth contour maps of Lower Goru Formation and Basal Sands help us to confirm the presence of horst and graben structure in the given area. This horst and graben structure acts as a trap in the area, which is best for hydrocarbon accumulation. In the Formation Evaluation of Lower Goru the zones were studied on the basis of the different log suites. Porosity, Volume of shale, Resistivity of the Formation water and saturation of formation water was determined in order to assess the Hydrocarbon potential of the Lower Goru. Petrophysical results are particularly valuable in mature field settings where hydrocarbons are known to exist but their exact location, pay, lateral variations and other properties are poorly defined. After all the major work unconventionally Hydrocarbon reserves has been calculated which gives a rough idea about the amount of reserves present in the area and also pressure of overlying rocks on the reservoir.