Petrophysical Analysis of Zamzama Gas Field, Southern Indus Basin, Pakistan

Abstract

The purpose of the study is to evaluate hydrocarbon potential of the Zamzama gas field and structural and stratigraphic correlation among the wells. Tectonically, Zamzama gas field lies in Kirthar fordeep, compressional regime where thrust and anticlinal structures are present. The study area lie in Southeren Indus Basin, District Dadu, Sind province, Pakistan. The wells data of Zamzama North 01, Zamzama 02 and Zamzama 03 (located in Southern Indus Basin) was acquired from Land Mark Resources (LMKR), Pakistan with prior permission from Directorate General of Petroleum Concession (DGPC), Zamzama wells have been evaluated on the basis of well logs. Neutron log, density log, gamma ray log and resistivity logs were analyzed for petrophysical analysis. The methodology adopted to complete this task include, the measurements for the shale volume by using gamma ray log, porosities of the reservoir zones by density and neutron log, resistivity of the formation fluid by using resistivity log, water and hydrocarbon saturation using Archie's equation. Based on petrophysical results, it is concluded that Pab Sandstone is hydrocarbon bearing formation in Zamzama North 01 and Zamzama 02 wells while in Zamzama 03 it is water wet. On the basis of the stratigraphic correlation of Pab sandstone good quality sands are expected in the southern portion (Zamzama 02) because thickness is increasing towards south. Reservoir sand (Pab sandstone) is thick in the south and thins towards the north. Structural correlation is used to interpret the subsurface structures. Zamzama 02 well is present on the crestal portion while Zamzama North 01 and Zamzama 03 wells are present on the flanks of the structure. Pab sandstone is the producing reservoir in Zamzama area and it has good potential.