Structural styles, hydrocarbon prospects, and potential of Miano and Kadanwari fields, Central Indus Basin, Pakistan

The main purpose of this paper is to evaluate the structural styles of Miano and Kadanwari Fields, located in the Central Indus Basin, Sindh province, Pakistan. Discovered in 1989 and 1993, Kadanwari and Miano Fields are located on the Pano Aqil graben and Kadanwari High, in between two extensive NW-SE-oriented regional highs, i.e., Jacobabad-Khairpur and Mari-Kandhkot High. The Central Indus Basin is an extensional basin exhibiting normal faulting. Fourteen seismic lines were interpreted to understand the presence, trend, and development of the fault system in the Central Indus Basin along with the assessment of the Petroleum system based on the analysis of seismic reflection data and well logs across the Cretaceous clastic reservoirs. The tectonics of Miano and Kadanwari Fields has been interpreted with the presence of normal faults, strike-slip faults, and inverted structures leading to ambiguities about the structural framework of the area. However, with this detailed study, an extensional fault system has been interpreted in the Cretaceous and lower Tertiary sections over a detachment in the incompetent Sembar Formation. In Miano Field, the faults are dominantly recognized to have NNW-SSE trend due to NW-SE-oriented extension related to northward drift of Indian Plate from Madagascar. Resultantly tilted fault blocks of half grabens geometry have developed in the area depicting bookshelf geometry of an extensional system Wrench fault system is found to be absent with exception of a probable strike-slip fault in the Kadanwari Field. The fields are interpreted to have significant recoverable reserves of 1662 (bcf) equivalents to 280 (mmboe) in tilted fault blocks having an average displacement of about 50 m.