Abstract:
Mubarak block is present in Ghotki area Sindh,Central Indus basin.Due to
extensional tectonic regime normal faults are present in this area.Jurrasic to most
recent rocks are present in its stratigraphic sequence.The most promising formation in
this area is Lower Goru as it contains thin interbedded sandstone and shale. This study
has been carried out in Rehmat gas field (Mubarak block).The provided data was
seismic 3D data and well data of Rehmat-02.The purpose of study is to know the
potential of Lower Goru formation.Structural and stratigraphic interpretation of 3d
seismic data, fault geometry mapping and time and depth contour maps are main
methods used to complete task. Three horizons are marked Sui Main Limestone, Upper
Goru and Lower Goru Formation. Due to extension normal faults are developed which
divide the area into horst and graben structures which play an important role in
reservoir compartmentization.For estimation of fluid potential petrophysical logs are
applied. Only one reservoiz zone of significant thickness and hydrocarbon saturation
was marked.The estimated volume of shale varies between 20%-30%, effective
porosity between 10-11% and saturation of water from 20-30%. Estimation of sand
channels and detailed reservoir characterization is done by post stack inversion. Model
based inversion technique play an important role in understanding lithology and
porosity of B-interval reservoir. Model based inversion gives appropriate estimation of
acoustic impedance and lithology. North to South impedance value increases and from
East to West it decreases.At the encounter of Lower Goru formation, there is sharp
increase in acoustic impedance showing low porosity value above and below well
location and at well location low impedance value suggest high porosity which show
presence of hydrocarbons. Hence, the study shows Lower Goru formation of
Cretaceous has potential to produce hydrocarbon at commercial scale.
