Abstract:
The present study interprets the subsurface structure of Chanda field of
Shakardara area. Structural and Stratigraphic interpretation, seismic attribute analysis,
Petrophysical analysis and Facies modeling of the area has been done. Navigation data,
SEG-Y data and well log data has used for study. In northern Pakistan the shakardara
area is the most complex area. OGDCL is the operator of Shakardara block which
means seismic data is acquired and processed by OGDCL. For interpreting seismic lines
three reflectors and thrust faults were marked on petrel software by using interactive
tools. Fault polygon generation, synthetic seismogram, time contour maps and depth
contour maps are also the part of seismic data interpretation. The marked horizons were
identified using Formation tops by well data and depths were confirmed through
correlation with synthetic seismogram from Density log (RHOB) and sonic log. Time
and depth contour maps of different horizons that are marked were generated to collect
knowledge related to the geometry of structures and nature of geological structures as
identified by the seismic section of the area. The tectonic regime of the study area is
compressional as thrust faulting is seen on the seismic sections. The Pop-up and Duplex
structures formed by thrust faulting are confirmed on interpretation of these seismic
lines. Shallower portions or Pop-up portions in the structure are suitable for
hydrocarbon traps. Attribute analysis technique is used on seismic sections to enhance
and interpret different lithological boundaries and confirmation of subsurface structural
disturbance. Petrophysical analysis of Chanda-1, Chanda-Deep1 and Chanda-2 wells
revealed that the Datta Formation has good reservoir potential as it has good porosity
and Hydrocarbon saturation. In Lockhart Formation the primary porosity is not good,
whereas Patala has good shale volume that shows it as a good source of Hydrocarbons.
Facies modeling is a good source to identify and confirm the lithology. The facies
analysis of these wells revealed that Lockhart Limestone on the basis of secondary
porosity and Datta sandstone are good reservoir lithologies of the study area.
