Thermal characteristics of the X geothermal resources, and a recommendation on utilization possibility

Abstract

Like in petroleum, geothermal has a high cost and risk in exploration, development including drilling and utilization. This needs a clear definition and understanding of the nature and characteristic of the system in question, so the increasing of investment cost and risk could be mitigated. Un-like in the petroleum industry, reservoir engineering and geoscience are intricately intertwined in geothermal. Considering this issue, in this study the author has integrated the results of reservoir engineering analysis with geoscience concept, to determine the up-flow zone, is a zone with high thermal potential and high permeability, so it can develop as geothermal field. It was conducted at a geothermal prospect in Indonesia located at the average altitudes of about 1000 meter above sea level (m.a.s.l), where 26 wells have been drilled. The research focus in characterising of the system, using wellbore temperatures and pressures measured. This will conclude the reservoir temperature and pressure as well as enthalpy, and up-flow zone by deploying several methods and approach: namely Horner temperature, BPD curve and Pivot concept, and thermal conductivity or heat transfer concept which applied in geoscience. The research includes a literature review on heat energy conversion to electricity based on reservoir temperature and or enthalpy approach, which is used to recommend the conversion system that can extract the heat efficiently. In addition, the question on location of the up-flow zone has been answered by this study, i.e. in the southern part of the field.