3D GEOLOGICAL MODELLING : AN ADVANCED METHOD TO BUILD GEOLOGICAL BASELINE MODEL IN HULULAIS GEOTHERMAL PROSPECT, BENGKULU, INDONESIA

Abstract

Pertamina Geothermal Energy (PGE) conducts exploration and exploitation stages of geothermal energy in 14 working areas owned by Pertamina throughout Indonesia, one of them is Hululais geothermal project in Bengkulu, Sumatra.
Exploration stage of Hululais geothermal project is proven by drilling campaign activities since 2010 in order to fulfill steam production and injection capacity of 2 x 55 Mwe units. The subsurface geological data obtained through the exploration wells is integrated into a geological model, using 3D geological modelling software.
The result of this analysis and modelling is a 3D geological model that integrates various data as a lithology model, alteration model, and temperature distribution model. 3D geological modelling is an important step in Hululais post drilling evaluation. With the increasing data acquired during both surface and subsurface exploration activities, this 3D geological model will evolve with the dynamism of the exploration and exploitation process in Hululais project.
This 3D geological model will be made as the baseline in the early phase of development of Hululais geothermal project. In the future, any changes that occur during its exploitation process can be monitored and recorded from time to time.