Utilizing Geophysical Methods for Geothermal Exploration

Abstract

Geothermal energy can be retrieved and simply generate
energy on par with the out-turn of other types of energy
fabrication such as nuclear reactors due to its abundancy.
Geothermal reservoirs are one of a naturally occurring
hydrothermal resources. In this study, three geophysical
methods were used to Pole-dipole array with an electrode
spacing of 5 m was used during the application of 2-D electrical
method meanwhile for magnetic method a proton precession
magnetometer device and Global Positioning System (GPS)
navigation were used when the method performed. Total of four
survey lines were conducted for 2-D electrical and magnetic
method in which a data correlation between these two methods
will then be used for data interpretation. Inversion of apparent
resistivity data to a 2-D electrical model section was done using
a RES2DINV software while for the magnetic data, Microsoft
Excels and Surfer 10 software was used and presented in a
form of contouring in which discovered the fault zone. Analytic
signal map was produced from Surfer 10 and showing high
magnetic value in geothermal locality which is about >10 nT
while resistivity gives a low value of 10 Ωm and IP shows high
chargeability value of 40 msec. Increasing of iron oxide causing
the magnetic intensity to be high while increasing in temperature
resulted in low resistivity value. Most of the fractures occurred at
depth of 100 meters and above with size of approximately 20
meters. The presence of fractures is associated with the major
fault in a geological map which occurred along the study area