2D Seismic Interpretation And Petrophysics Analysis Of Balkassar Oil Field, Upper Indus Basin, Pakistan

Abstract

The goal of this study is to understand the structural foundation and reservoir potential of the Balkassar area. The Potwar Sub basin, well recognized for its hydrocarbon structural traps, encloses the Balkassar area in the Himalayan collisional regime. The Potwar Plateau is one of the world's oldest oil regions. Several hydrocarbon fields have since been identified in various regions of the plateau. Most of these discoveries are correlated to subsurface reversal faults, duplexes, and anticlines (salt-cored anticlines). Study was performed in two phases. In the first step, horizons were marked using synthetic seismogram and time, depth, and velocity maps were made to analyze the available seismic lines. According to the 2D seismic interpretation of the study area, Balkassar is a gentle anticlinal pop-up structure bounded by thrust faults. Though petrophysics analysis the hydrocarbon potential of the Balkassar-OXY-01 well using wireline data was assessed. Among the petrophysical logs used in this study were gamma-ray, neutronporosity, resistivity, caliper, fluid-density, and spontaneous potential. Within the Chorgali Formation two potential zones have been marked. Petrophysical research has revealed two zone in Chorgali reservoir, in zone 1 which has 3 % average porosity, 2.5%effective porosity 55% water saturation, and 45% hydrocarbon saturation and in zone 2 has 2.6% average porosity, 1.8% effective porosity, 90% water saturation, and 10% hydrocarbon saturation. While in Sakesar Limestone we did not mark the specific zone because the criteria of zone of interest were not fulfilled. That’s why Chorgali formation is a economically good reservoir as compared to Sakesar Limestone.