Generation of Stratal trends through Geological data Integration of Sawan gas Field, Central Indus basin, Pakistan (T-1411) (MFN 4993)

Abstract

Sawan gas field area is located near the Khairpur district, Sindh, Pakistan. This gas field is discovered in 1998 and have a very high gas potential. Lower Goru Formation is the possible reservoir in Sawan gas field and in other associated gas fields. It is studied by the aid of available wireline logs data. Lower Goru formation lies in the Central Indus Basin, Pakistan and divided in different sand units on the basis of their variegated behavior. Lithology of Lower Goru Formation includes majorly sand deposits with interbedded shaley content while calcareous deposits are rarely found. Hydrocarbon productive reservoir is the C-sand unit of Lower Goru Formation in Sawan gas field and encountered at the depth of 3272 m to 3397 m. Here the possible petroleum source rock is Sembar Formation and seal is Upper Goru Formation and form a good trapping mechanism. Petrophysical evaluation is done on the C-sand reservoir at Sawan field and estimated the volume of shale, effective porosity and water saturation to elaborate net pay thickness of the reservoir rock. Net pay thickness averages from 27.1 m to 35 m. Gamma ray logs are used for depositional facies analysis of the reservoir unit and marks the progradational and retrogradational phenomena of deposition while environment of deposition varies from deep marine to shallow marine. Startigraphic correlation shows a northeast to southwest trend and the formation is thinning towards north direction. Structural correlation reveals that the formation has a northeast dipping trend. Isopach maps indicate a change in thickness from northeast to southwest. Increase and decrease in thickness character indicates a change in depositional environment from shallow to deep marine.