Reservoir Evaluation Using Seismic Interpretation and Petro physical Analysis of Balkassar Oil Field, Upper Indus Basin, Pakistan

Abstract

Balkassar is one of the oldest and tectonically most complex onshore oilfields in the world. Geologically, the subsurface impression is a flat-topped, salt cored, pop-up anticline and the area has a well-developed petroleum system. The major part of oil/gas has been produced from fractured carbonates of Eocene Chorgali and Sakesar formations. This study aims to interpret the limited available seismic and well data to evaluate the structural trap, the sealing effect to check the cross fault leakage in order to assess the hydrocarbon storativity of the structure and then the producible hydrocarbon potential. To achieve this goal, 2D seismic data is interpreted, fault/seal analysis using Allan Diagram and petrophysical investigation is carried out. Seismic interpretation suggests that the structure is conducive to hydrocarbon accumulation and fault/seal analysis indicates optimum trans hydrocarbon entrapment. fault sealing effect for Now, to quantify the hydrocarbon potential wireline logs suite from well Oxy 1 is used, three zones of interest marked and interpreted to characterize formation fluids and potentially productive sections. Hydrocarbon potential reveals a range of 30% 65% producible reserves across the three zones of interest.