Lithofacies Description and Fracture Evaluation of
an Unconventional Reservoir in Borehole
Imaging in a Geothermal Reservoir Characterization
Chitale, D. V. (Vivek)1, Ramon Sanchez2 (1) Halliburton
Energy Services,
Role of an electrical borehole
image becomes especially critical
in reservoir characterization when the only other well data available are
gamma- and temperature logs! The challenge becomes even bigger when the
reservoir to be characterized is non-conventional and it contains geothermal
energy! This paper reports such a case history documenting a successful
application of
borehole
imaging in characterizing geothermal reservoirs of
An Operator in Borehole
images were interpreted to
accurately describe the litho-facies and diagnose
fractures holding the geothermal energy. Image interpretation software called
“sculpturing” (Chitale et. al. 2004) was used to
quantify the fractured porosity.
This paper shows
how XRMI and the software “sculpturing” achieved characterization of the andesite reservoirs containing geothermal energy, which was
done without any help from other logs except gamma- and temperature. Further,
the borehole
images differentiated reservoirs from shales
or impermeable rocks, which proved crucial for the Operator since the common
shale indicator- gamma log was affected by radioactive minerals in the volcanics.
Borehole
images also enabled core-like
description of the litho-facies thereby saving costs
of conventional coring in a tough
borehole
environment. Thus,
borehole
imaging
proved critical in the reservoir development efforts and significantly reduced
the E&P risks for the Operator in these geologically complex areas of