2D Seismic Modelling And Reservoir Characterization Using Seismic And Well Data of Balkassar Area, Upper Indus Basin, Pakistan.

Abstract

The dissertation work includes seismic data interpretation, Petrophysical analysis using well logs data; for the identification of possible prospect (H.C) zones. The technique of seismic inversion is also used to get more clear results about possible hydrocarbon zone. Facies modeling for the confirmation of lithology’s. Two-dimensional seismic data interpretation has been carried out in Upper Indus Basin, Balkassar area to confirm the reservoir characteristics of Chorgali and Sakesar Formation. Time and Depth contour maps of Chorgali and Sakesar help us to confirm the presence of anticlinal structure in the given area. Surface contour maps of Chorgali and Sakesar Formation give the real shape of sub-surface structure, which is anticlinal. This anticlinal structure acts as a trap in the area, which is best for hydrocarbon accumulation. Petrophysical analysis of well BALKASSAR OXY-01 is carried out for Chorgali, Sakessar formations to depict the probable hydrocarbon producing zones. The results suggest that both Chorgali and Sakessar formations are possible hydrocarbon reservoirs. One zone is marked in Chorgali having SW 33% and H.C Saturation 67% and three zones in Sakessar having SW 2942% and H.C Saturation 58-71% which is most prominent and possible hydrocarbon zones. Facies modeling is done for the confirmation of lithologies for this purpose different cross plots has been generated which gives the result that we have pure limestone, and carbonaceous shale (limy shale) but didn‘t get pure shale in our reservoir zone. Seismic inversion results are also showing that Chorgali and Sakesar act as a reservoir. The post stack colored inversion is performed to confirm the possible hydrocarbon prospects. On inverted section Chorgali and Sakesar shows low value of impedance i.e. strong indicator for the presence of hydrocarbons, it is also confirmed from Petrophysical results.