2-D SEISMIC INTERPRETATION AND RESERVOIR CHARACTERIZATION OF TAJJAL AREA, LOWER INDUS BASIN SINDH, PAKISTAN

Abstract

The dissertation pertains to locate structures favourable for hydrocarbon accumulation using seismic and well data and Petrophysical interpretation to evaluate reservoir properties. The interpretation was performed on seismic lines GT J88-206, GT J88-207, GT J89-516 and GT J89-522 and on well KADANWARI-14. For the interpretation of the seismic lines, two reflectors were marked by correlating synthetic seismogram on seismic section. As the area of study lies in the lower Indus basin, horst and graben with associated normal faults are present. Seismic attribute (instantaneous phase) is applied to confirm the interpretation. Instantaneous phase tell us about lateral continuity and trace envelope about reflection strength of reflectors. Petrophysics uses combined response of different logs on the basis of which we mark possible hydrocarbon bearing zones. Lower Goru formation of lower cretaceous age is present in the study area in which the sands of lower goru are acting as thin pay zones and are acting as reservoirs. We performed Petrophysical analysis and check response of different logs in the depth range of 3075m to 3500m. Two possible Hydrocarbon bearing zones were marked in this depth on the basis of Petrophysical analysis. Average effective porosity was calculated to be 13% in zone A and it is 15% in zone B, water saturation 49% in A zone and 32% in zone B. Hydrocarbon saturation was found to be 50% in zone A and that in zone B was 67%.