2D SEISMIC DATA INTERPRETATION INTEGRATED WITH RESERVOIR CHARACTERIZATION OF BALKASSAR AREA,UPPER INDUS BASIN,PAKISTAN

Abstract

Reservoir characterization using seismic and well data is a renowned technique within the content of hydrocarbon exploration. This study retains to the interpretation of seismic lines, wireline logs,rock physics and colored inversion for better visualization of important feature at reservoir level. The study area selected for this purpose is Balkassar area. In this dissertation, Two-dimensional seismic interpretation has been carried out in upper Indus Basin, Balkassar area to find the subsurface geological conditions or in order to demarcate the Probable zone for the accumulation of hydrocarbons. The horizons were marked with the help of provided well information (Balkasar OXY-1). The interpreted faults on each seismic section indicate the area belongs to compressional regime. From the given sections we could recognize the sub surface structure which was faulted at limbs. Two way Time and Depth contour maps at the top of Chorgali,Sakesar and Patala were constructed that showed the sub-surface anticlinal ‘Pop up’ structure faulted at the limbs,which is one of the most favorable structure for oil and gas accumulation. Analysis of geophysical borehole logs provides one of the best approache to characterizing rocks within borehole. we find out different properties of rocks ( volume of shale, Porosity ,Permeability and hydrocarbon saturation) and combination of different log results helped us to find out hydrocarbon potential zones.To discriminate between different lithologies we cross-Plotted different parameters, this helped us to separate reservoir from shale.Lithology of reservoir was limestone with interclation of shaly limestone. Petrophysical analysis of Balkassar oxy-1 well showed that chorgali and Sakesar formations have hydrocarbon Potential and Some oil zones were recognized. The lower part of Sakesar Formation shows indication of maturity or reservoir shale. Rock Physics is a powerful tool for reservoir characterization,it is applied to confirm the Petrophysical result by observing the trend of elastic Properties in a zones of interest. Seismic inversion results are also demonstrating that Chorgali act as a reservoir. The post stack color inversion is performed to confirm the leads location. On inverted section Chorgali shows low value of impedance i.e. strong indicator for the presence of hydrocarbons