Abstract:
Mehar is present along the eastern front of Kirthar Fold belt, in the lower part of the
Central Indus Basin, onshore Pakistan. Mehar is one of various gas producing from
Late Paleocene and Cretaceous clastic reservoirs in Lower Indus Basin, Pakistan.
Seismic data available for Maher Block shows the presence of a large anticline in the
subsurface of Mehar block which is bounded by a large reverse fault in the East. In
west, all the reflectors are highly dipping. A large north-south trending reverse fault
disturbed the strata from Eocene age to the basement rocks in this area. This reverse
fault may be generated due to the disturbance caused at the end or after Eocene time.
Petrophysical analysis is done for Mehar-02 well to estimate the hydrocarbon saturation
of potential zones for Pab Sandstone. Only two small potential zones were marked
within Pab Sandstone and Ranikot formation having hydrocarbon saturation around
70% and porosity ranging in between 6-7%. Seismic inversion analysis was done over
the 3D seismic cube of Mehar Block. Model based inversion makes the very model
having 99% correlation and only 0.08% error. The colored inversion analysis shows the
correlation of 80% over the provided seismic data of Maher Block. The correlation for
sparse-spike inversion was also 99% which is very good. Colored inversion shows the
change in lithology down the strata and shows the low to moderate values for both Pab
and Ranikot Formations. Similarly, sparse spike inversion is also done and shows the
change in lithology at every interaction of two different Formations. All these inversion
techniques help to generate and analyze the impedance model for Maher Block where
the model-based inversion and sparse-spike inversion shows the best results. Inversion
methods help to identify the low to moderate character of the Pab Sandstone and
Ranikot Formation.
