Abstract:
The geophysical study based on the 2-D seismic lines; 01782-CW-24, 017tC-CW-26, 0/855-CW-01, 0/855-CW-02, and 0/855-CW-03, was can-ied out in the Chak Naurang (Potwar Sub basin) area. The objective of this study was to delineate the subsurf~lce structure and assess the processes and forces responsible for the trends observed. The interpretation carried out on the above mentioned lines indicated the presence of three prominent reflectors, marked R I, R2 and R3. Correlation with well data expressed these rdlectors to be Chorgali Formation, Khewra Sandstone and the Basement respectively. A major fault \vas marked on each of the line s(;ctions displaying the same orientation. In lines 01782-CW-24, 01782-CW-26, and 0/855-CW-Ol the fault extended all the way to the Pn:-Cambrian basement. Two-way travel times (TW1') w(;re picked against shot points (SP) on all the seismic sections. These times were then postee\ on the base map to generate time contour map of the Upper Eocene Chorgali Formation, as it was the reservoir formation continuing throughollt the area. A verage velocities for the three
formations were calculated using seismic RMS velocities given in the velociry windows on the seismic sections. The average velocities and the one-way travel times were used to calculate depth values of the formations. The seismic section showed that the area was structurally dcfo1111Cd due to salt decollement and compressional tectonic movements. Trap l'or hydrocarbons was developed in the ::mticline as it truncated against the h~1Setllel1t bult. Salt movement was probably due to compressional movements. The Chak Naurang anticline was the prospective zone and the primary target for oil exploration
