2D seismic interpretation of Balkassar area, Pothowar plateau, upper Indus basin, Pakistan (P-1231) (MFN 7024)

Abstract

Five of the prominent reflectors were Chorgali Formation, Sakesar Formation, Lockhart Formation, Tobra Formation and Khewra Formation were marked on the seismic section on the basis of observed seismic reflection. A fault was marked too which continuities along the Precambrian basement. Two other thrust faults were marked which showed fault propagating folds in the form of anticlines of Balkassar. A time section was produced from the seismic section using the shot points and two way time (TWT) of the reflectors and faults which were marked. Time contour map of the formation was generated by using the TWT which was posted on the base map. Using the seismic velocities given in the velocity windows on the seismic section we find the average velocities of the formations. Then these average velocities were used to find the depths of the formations for the seismic section. The well data of Balkassar Oxy-01 was used to confirm the depth of reflectors. The geo-seismic section gives us the information that the area was structurally deformed due to multiple reasons which were salt decollement and compressional tectonic movements. Most of the Hydrocarbon traps were developed in the anticline as they were truncated against the thrust fault. Pop-up structures were formed due to the movement of the salt into the anticlines. The Balkassar anticline was primary target zone for oil exploration, where the depth of the Chorgali Formation was almost 2400m, favorable for Exploration and drilling.