Integrated Charge Assessment in Nashpa Block Area of Kohat Fold and Thrust Belt of Pakistan

Abstract

The main goal of the 2D basin and petroleum systems modeling (BPSM) study was to understand the petroleum systems elements and processes in Nashpa Block Area of Kohat Fold and Thrust Belt (FTB) of Pakistan, including generation potential of presumed source rocks, timing relationship between hydrocarbon charge and trap formation, role of the faults in hydrocarbon migration and accumulation, uncertainties related to input parameters, and last but not least to support the risk matrix concept to increase the confidence in assigned risk values. The area of interest (AOI) of the 2D BPSM study is located west of the Indus River in the Kohat Basin which together with Potwar Basin are considered as part of Sub-Himalayan Tectonic Province demarcated by the Main Frontal Thrust (MFT) to the south and the Main Boundary Thrust to the North (MBT). The Main Boundary Thrust displaced the Mesozoic rocks over Eocene to Miocene rocks in the footwall. This major compression created the Kohat and Potwar foreland basins defined by thin-skinned tectonics of thrust and duplexes (Wandrey et al. 2004). In the area with very complex structural movements the potential traps located on regional antiforms are the consequences of the compressive deformation triggered by the collision of the Indian plate into the Eurasian plate. In addition to the general north-south shortening, additional displacement events took place as well, which significantly enhanced the properties of the Mesozoic-Paleocene reservoir rocks through fractures (Wandrey et al. 2004).