RESERVOIR CHARACTERIZATION OF PIRKOH GAS FIELD, CENTRAL INDUS BASIN, PAKISTAN

Abstract

Pirkoh Gas field is prolific gas-producing block situated in the Middle Indus Basin in Pakistan. Middle Indus Basin contains several developments and production (D & P) leases, which are producing gas from Cretaceous rocks. The present study aimed to evaluate the Seismic data and well data as well. In seismic interpretation four reflectors were marked on seismic sections and then time and depth contour maps of selected horizons were prepared to find time and depth variations of these reflectors in the study area. Moreover seismic attributes analysis is done to verify interpretation and to find reservoir properties of reservoir rock (Pab sandstone). It has been observed that structure of Pirkoh gas field is an anticlinal closure bounded by a main thrust fault and back thrust fault that were generated as a result of collision of the Indian and the Afghan block. Petrophysical properties of the Pab Sandstone were revealed by using well log data. This study shows that the reservoir quality sands are deposited in the study area. Lithology identification neutron-density cross plot techniques used for lithology verification. Neutron & density cross plots shows that the major lithology is sand in addition with some portion of shales and shaly sands. Sand packages identified in the Pab Sandstone do have good porosity values. Multiple small reservoir intervals have been identified in both the wells having pay zone of 39.9 m in Pirkoh-01 well and 18.1 m in Pirkoh-32A wells. The results show that the Pab Sandstone holds good hydrocarbon saturation.