A Concise Discussion of Geothermal Slimhole Drilling In Indonesia: What Are The Challenges and Considerations?

Indonesia is one of the countries known to be in the "Ring of Fire" area which has a 23.36 GW geothermal potential, or equal to 40% of the geothermal energy potential in the world. This proves that Indonesia is one of the largest geothermal resources in the world. Geothermal exploration requires a long process and time before geothermal energy can be produced and used because it is located deep below the earth's surface. However, there are some challenges such as limited rig availability, most of the well pads for geothermal projects in Indonesia being located in conservative areas or in protected forests, and many more.

Slimhole drilling is a drilling method designed with lower costs incurred during the exploration phase compared to standard or big bore drillings. Therefore, the slimhole drilling method can be used as a solution to minimize the risks during the exploration phase. But alas, geothermal project development requires very high initial costs and high uncertainty, which might cause geothermal energy in Indonesia cannot to be utilized optimally.

The purpose of this paper is to illustrate slimhole drilling efficiency technically and economically. The method of this paper is to study various information and experiences regarding geothermal slimhole drilling from previous publications and research domestically and internationally. Several things mentioned above may cause investors to be reluctant to invest in geothermal projects in Indonesia. The paper is expected to give a concise discussion for the geothermal practitioners and companies about the advantages, limitations, and challenges of slimhole drilling and the application for an exploration phase.