Exploration Drilling Design of Low-Medium Temperature Field In West Nusa Tenggara, Indonesia

The Government of Indonesia continues to boost the development of new and renewable energy. Through the PLN’s General Plan for the Provision of Electricity (RUPTL) for the period of 2021-2030, the composition of power plants to be built over the next decade for NRE will reach 48% with total geothermal installed capacity reaching 7.24 GW in 2025. However, a most remaining geothermal fields in Indonesia are identified as low to medium temperature reserves. Where some of these fields do not yet have 3G survey results and/or do not have conclusive manifestations. Exploration drilling will be the only option to prove the existence of the geothermal resource. One of the prospect areas with low-medium temperatures is in West Nusa Tenggara. This area is composed of young volcanoes (the northern part), older formations (the southern part), and is separated by an alluvial depression. The 3G survey has been done in this field and there are active manifestations in the form of warm springs. Finally, this paper aims to propose an exploration drilling design for a low-medium temperature field in West Nusa Tenggara. It is designed to minimize exploration cost, then maximize the likelihood of intersecting a geothermal reservoir, also provide an assessment of the volume of the system, and allow the option to drill a standard diameter well to obtain greater levels of steam production.