Assessment of the probability of success and risking in hydrocarbon exploration: A case study from Zindapir Anticline, Sulaiman Foldbelt, Indus Basin, Pakistan

Abstract

Role of the statistical calculation is very important in petroleum exploration business. It is used to calculate the associated risk and determines the chances of geological success prior to drilling of an exploratory well in mapped prospect area. This manuscript is focusing on the geological modelling of Zindapir Anticline, Sulaiman Fold Belt, Indus basin, Pakistan using mainly based on the concept of probability developed by Coordinating Committee for Coastal and Offshore Geoscience Program (CCOP) in East and Southeast Asia in 2000. Study area comprises of Zindapir Anticline with two abandoned wells Well X-1 and Zindapir-1 which were drilled and declared as dry holes. Detailed geological modelling indicates that Zindapir structure is still virgin to flow hydrocarbons, and there are ample chances of compartments, which were developed as result of transpressional movement at the periphery of the structure. Interpreted seismic line also supports the presence of different compartments in structure. These compartments may host hydrocarbon, generated and migrated either from Bharti Syncline and Sulaiman Foredeep or generated by indigenous source rocks possibly deposited in the south of Zindapir-1 and Well X-1. Presence of trap, hydrocarbon charge and reservoir in Zindapir structure indicates there is better probability of success for hydrocarbons, and good chances for the development of traps because of transpressional movement. Traps may contain the hydrocarbon, possibly generated from Bharti Syncline in west and Sulaiman Foredeep in east whereas southern part of Zindapir Anticline was not considered, and northern part of Zindapir Anticline was mapped with very open grid size. Present seismic data is limited which is the major reason that due to poor probability of effective trap it is recommended to acquire additional seismic data for further detailed picture structure of Zindapir Anticline. An equation for the calculation of geological chances success for new development well is also proposed in this manuscript.