The Patuha geothermal system: a numerical model of a vapor-dominated system

Abstract

The Patuha geothermal system is a vapor-dominated reservoir located about 40 kilometers southwest of Bandung on western Java, Indonesia. The geothermal system consists of a cap rock, an underlying steam cap and a deep liquid-dominated reservoir. The reservoir is provided with heat by a main heat source below Kawah Putih and the Patuha volcano. The flow of fluid takes place through fault zones and in the low permeability reservoir rock. A straightforward numerical model of the system has been developed in Petrasim, which is a graphical interface of TOUGH2. The modeled reservoir consists of three homogeneous segments: the cap rock and (vapor- and liquid-dominated) reservoir rock, which are crosscut by fault zones initiating vertical fluid flow. It has been demonstrated in this study that the Patuha vapor-dominated reservoir resembles the theoretical design for a vapor-dominated geothermal system. The Patuha geothermal system can thus be represented by such a simple and straightforward model.