Evaluation of Hydrocarbon Potential in Zamzama Gas Fields, Southern Indus Basin, Pakistan, Using 2D Seismic Interpretation and Attribute Analysis

Abstract

Zamzama gas field is a large thrusted anticline on the east edge of Kirthar fold belt. It is a concession block operated by Orient Petroleum Inc. Zamzama gas field is situated 10 Km west of City Dadu in province Sindh, Pakistan. Zamzama gas field was discovered in 1998. The locality of the research area exists in Southern Indus Basin. The research area is surrounded by Sukkar rift to the northward side, and Karachi trough to eastward side. At present thirteen wells has been drilled in this area. The highest production of ~600 MMSCFD gas was acquired in 2009 from Zamzama 2. OPI plans to drill further wells in the area. The previous literature e.g. interpretation and attribute analysis indicate that Pab sandstones show constant thickness across the entire structure. Pab sandstone reservoir has a top seal which is supplied by marine shale of the Girdo (Ranikot) Formation. The main source rocks in this area are Sembar and Goru shales. The fault geometry identification of Zamzama Gas Field is complex step which can only be delineated by interpreting the reprocessed data and running multiple attributes. Chaotic reflectors indicate parallel faulting and compartmentalization in the structures. These compartments are responsible for the hydrocarbon entrapment. The structural entrapment is providing reservoir potential and future prospectively in the area.