Japan Geoscience Union Meeting 2025

Presentation information

[E] Poster

S (Solid Earth Sciences ) » S-RD Resources, Mineral Deposit & Resource Exploration

[S-RD24] Cutting-edge sensing technology applied to geology and resource exploration

Fri. May 30, 2025 5:15 PM - 7:15 PM Poster Hall (Exhibition Hall 7&8, Makuhari Messe)

convener:Yukihiro Takahashi(Department of Cosmosciences, Graduate School of Science, Hokkaido University), Mohd Hariri Arifin(Universiti Kebangsaan Malaysia), Mirzam Abdurrachman(Institut Teknologi Bandung)

5:15 PM - 7:15 PM

[SRD24-P05] Understanding Natural Recharge for Sustainable Production over 4 decades of Kamojang Geothermal Field, Indonesia

*Yayan Sofyan1, Lendriadi Agung2, Syamsu Rosid3 (1.West Japan Engineering Consultants, Inc., 2.Pertamina Geothermal Energy, 3.University of Indonesia)

Keywords:Natural recharge, Microgravity, Sustainable production

Fluid extraction from geothermal reservoir creates a hydraulic variation that leads to hydraulic gradients and corresponding to fluid inflow to fill the reservoir(1). Natural recharge, a natural influx of fluid from surrounding into geothermal system, is an important factor in the lifetime of geothermal resource and sustainability of geothermal production. The recharge rate is strongly influenced by regional factors around the geothermal field when fluid entering the earth occurs continuously, accumulatively over a certain period of time.

Natural recharge rate in Kamojang geothermal field (KGF) varies throughout the production year over four decades. Together with production and injection data, monitoring of varying microgravity over a certain period can estimate the natural recharge rate of fluid entering the reservoir. With 5 operating units producing 235 MW, KGF has an average production decline rate of between 5% and 7% and has the largest natural recharge rate supply of almost 9 Mton/year. Understanding the natural recharge of geothermal reservoir can lead to sustainable geothermal production.