Geological and Isothermal 3-D Model of Blawan-Ijen Geothermal System

Abstract

The Blawan-Ijen is one of the geothermal prospects in the eastern part of Java island, Indonesia. This prospect is situated in the caldera called the Kendeng caldera. The Blawan-Ijen has geothermal manifestations in two different locations, the Ijen crater in the southeast and Blawan in the northern part of the caldera. These manifestations are estimated to have different reservoirs. Different manifestations of characteristic and lithological complexity in the Kendeng caldera make the geothermal system contained in the caldera less known. Therefore, a 3D model was built on understanding the geometries of the Blawan-Ijen geothermal system. In this research, the model is limited to the geological and isothermal model. The data used in building the models are based on the literature and research data that has been done previously. Geological and isothermal models were built using Leapfrog Geothermal software. The 3D conceptual model provides a general overview of the geometries of the Blawan-Ijen geothermal system. The isothermal model shows temperature anomalies and their possible distribution.