Abstract:
This document represents the subsurface structural and stratigraphic evaluation
of the Upper Jurassic to Lower Cretaceous Sembar and Goru formations in Miano and
adjoining area of the Middle Indus platform. Thorough regional and petroleum
geological aspects of the study area are reviewed. Acquisition and processing
parameters of the seismic data are discussed. Six horizons, Sui Main Limestone
Formation, Upper Goru Formation, Top C Sands, Top B Sands, Top A Sands and
Chiltan Limestone Formation were picked. Two way time maps of all the horizons,
except Chiltan Limestone Formation, are prepared. Depth conversion is also done using
linear velocity function (LVF). Normal fault pattern with horst and graben features are
interpreted. Structurally the Miano area lies within a depression while the adjoining
areas in the east and west are uplifted. On the suitable seismic sections, the Sembar and
Goru (A-sand, B-sand and C-sand) strata are picked for every event to reveal the
seismic geometries (onlap, downlap etc.). This picking is used to develop a seismic
stratigraphic model. Two higher order sequences ( alternative TST and HST packages)
and one complete third order sequences (LST, TST and HST packages) are identified
within Sembar, whereas the Goru-A sand has one complete sequence comprising of
LSW (Lowstand Wedge), TST (Transgressional System Tract) and HST (Hishstand
System Tract). Areas for the potential plays are identified within Sembar Formation,
slope fans and shelfal sand bodies are interpreted as potential site for reservoir quality
sands.
