Integrated study of structural styles and their suitability for hydrocarbon entrapment, Southern Kirthar Fold Belt, Pakistan

Abstract

Present study is concerned with the interpretation of satellite imagery and 2D seismic profiles to understand the structural styles and petroleum system elements of the Southern Kirthar Fold Belt of Pakistan. Southern Kirthar Fold Belt is the part of regional Himalaya-Suleiman and Kirthar fold belt chain, which is produced in the Cenozoic due to collision and under-thrusting of the Indian Plate with Eurasian Plate. The exploration activities are being carried out in the study area since 19th century and number of gas discoveries are made, but many structures are still barren of hydrocarbons. Present study identifies four structural trends, which are 0, 350,330 and 020 in relation with 010 trending transpressional Ornach-Nal plate boundary. Three different styles of the studied anticlines are identified on the basis of seismic interpretation, which are anticlines cut by both fore-thrusting and back-thrusting reverse faults, anticlines cut by only fore-thrusting reverse faults and anticlines not cut by faults. Sufficient throw along the faults is identified in the seismic profiles, which can provide the juxtaposition trapping as well as recharging medium from the source to trap. Gas fields are discovered from the four out of six studied anticlines irrespective of style.