Structural Interpretation of Sohawa Area, Eastern Potwar Pakistan

Abstract

A seismic line O/20006-SWA-12, 0/20006-SWA-13, 0/20006-SWA-14 and O/20006-SWA-09 shot by OGDCL in year 2000, in Sohawa area (Eastern Salt Range/Potwar Plateau), is obtained from Directorate General of Petroleum Concessions (D.G.P.C). The lines under study are dip lines oriented southeast to northwest and strike line oriented southwest-northeast. These lines have been passed near the Hayal-01 Rajian-01 and Daiwal-01 wells. Three prominent reflectors namely R1, R2 and R3 were marked on the seismic section on the basis of observed reflection events. These reflections are interpreted as Eocene-Cambrian (E-C) sequences and basements. Three faults were also marked on the seismic section namely Domeli Thrust, Dil Jabba Thrust and Basement Thrust. A time section was produced from seismic section using the picket numbers and the two-way times (TWT) of the reflectors and faults. The seismic velocities (Vrms), given in the velocity windows on the seismic section, were used to find the average velocities of Upper Eocene Chorgali Formation and the Precambrian basement. These average velocities were then used to find the depths of the formations for the seismic section. Well data of Rajian-01, Daiwal-01 and Hayal-01 were also used to confirm the thickness of the different formations on the geo seismic section from cambrain to recent. The geoseismic section showed that the area is structurally deformed due to salt decollement compressional tectonic movement