Abstract:
The main purpose of the study is to evaluate the hydrocarbon potential of the study area, in a part of the Lower Indus basin i.e. Kadanwari Gas Field, and delineate prospects or leads. This has been achieved by sub-surface mapping using seismic data and its integration with the well data. Five seismic lines have been utilized along with Kadanwari well-3 data i.e well tops and check shots. The methodology adopted to accomplish this task includes; structural and stratigraphic interpretation of sparse 2D seismic data which has been correlated with well data; fault geometry mapping; manual time contouring of Late Cretaceous Top Lower Goru (TLG) and Eocene Sui Main Limestone (SML) horizons; and identification of potential leads on the TLG contour map. TLG is the most prospective horizon in the area. In this research, seven stratigraphic horizons have been marked and these include Top Pir Koh Limestone, Top Sui Main Limestone (SML), Top Ranikot Formation, Top Upper Goru Formation, Top Lower Goru (TLG) Formation, Top Albian-Aptain horizon and Top Chiltan Formation form shallow to depth. Top Pir Koh horizon shows a gentle easterly dip while the rest are relatively flat and are disturbed by the structural events. Structural interpretation of seismic data depicts two broad types of fault sets i.e. Vertical faults and plays faults. The study area lies in transtensional regime where horst and graben structures are associated. Both of these fault sets join together to form a negative flower structure in the projected area and are also considered responsible for the number of structural traps. Vertical faults are deep-seated and are of Cretaceous age while the splay faults are at shallow levels and are formed as due to the reactivation of deep-seated faults and northward drift of the Indo-Pakistan Plate. Structural and stratigraphic interpretation of the data provides a platform to assess potential leads and closures for hydrocarbon exploration. Three hydrocarbon leads have been identified at the level of SML while four hydrocarbon potential leads and closures have been identified in the area at the level of TLG. More data is required to raise the confidence level of the identified potential leads.
