Abstract:
The seismic lines OX-S88-20, OX-S88-23, OX-S88-36 and Bhangali-01 well,
obtained from Directorate General of Petroleum Concessions (DGPC), was shot by
Occidental of Pakistan Inc. in the area of Bhangali (Eastern Salt Range/Potwar
Plateau). The direction of the dip lines is NorthWest to SouthEast and that of the
strike line is SouthWest to NorthEast. Two prominent reflectors namely Chorgali
Formation and Basement were marked on the seismic section on the basis of observed
reflection events. A fault was marked which continued along the Pre-Cambrian
basement. Two more thrust faults were marked which show a fault-propagating fold
in the form of the anticline of Bhangali. The TWT picked from the seismic section
was posted on the base map to make a time contour map of the Upper Eocene
Chorgali Formation, as it was continuing throughout the area. The seismic velocities
(Vrms), given in the velocity windows on the seismic section, were used to find the
average velocities of the Upper Eocene Chorgali Formation and the Pre-Cambrian
basement. These average velocities were then used to find the depths of the formation
for the depth contour map of the Upper Eocene Chorgali Formation. Well data of
Bhangali-01 was used to mark the thicknesses of the individual formations and to
perform petrophysical evaluation. The interpreted seismic sections and the contour
maps showed that the area was structurally deformed due to salt decollement and
compressional tectonic movements. Traps for hydrocarbons were developed in the
anticlines as they truncated against the basement fault. Salt probably moved into these
anticlines due to compressional movements. The Bhangali anticline is the prospective
zone and is the primary targets for oil exploration, where the depth of the Upper
Eocene formation is almost 3600m, favorable for drilling.
