Abstract:
The purpose of this research is to conduct fracture analysis of Eocene carbonate
reservoirs (Chorgali and Sakesar) exposed in the Chorgali Pass, Potwar Basin, Pakistan.
The fracture analysis is done in terms of trend of open fractures. The main idea of this
research is to quantify the orientation of open set of fractures at different inventory
circle, to identify the most dominant fracture set produced as a result of regional stress;
so that the same can be used to propose a well trajectory which could encounter
maximum number of these regionally distributed fractures. The data gathered from the
field which was plotted on rose plots via Geo-Rose software, indicated the presence of
three dominant fracture sets namely A, B and C sets of fracture. A set of fracture was
found on every inventory circle with West North West (WNW) to East South East
(ESE) direction almost perpendicular to the direction of Indian-Eurasian plate collision,
the major source of deformation and stress build up in Indian Plate. Therefore, A set of
fractures have been concluded as regionally distributed fractures and deemed essential
for designing of any well trajectory targeted at these Eocene carbonate rocks, which
mostly lack the primary porosity. It is recommended that a horizontal well drilled
perpendicular to A set of fracture must be drilled in these hard and compact Eocene
carbonate rocks so as to encounter maximum number of open fractures, as these
carbonate rocks generally lack the primary porosity and much of the permeability
comes from open fractures.
