Surface Thermal Manifestation Monitoring of Kamojang Geothermal Field, West Java, Indonesia

Abstract

The Kamojang Geothermal Field is located in high volcanic terrain beneath the upper slopes of the Gandapura Volcanic complex in West Java, Indonesia. The field has been producing electricity since 1978. Currently, the total installed capacity of this field is about 200 MWe. For monitoring the changes of reservoir conditions, surface thermal manifestation monitoring is a powerful tool, which has been carried out since 1976. The main objective of this study is to assess the changes of water and gas compositions and the changes of physical parameters and geometry related to the changes of reservoir conditions.
The surface area of active thermal manifestation in the Kamojang field covers a small area along the eastern side of the field and includes hot pools, fumaroles, mud pots and hot springs. Most of the surface discharged fluid from the features are acid and contain high concentrations of sulfate, but very low concentrations of chloride. These concentrations are typically associated with vapour dominated systems.