Hydrothermal-activity stage classification and power-generation potential evaluation of geothermal wells based on a natural analog study on epithermal deposits, in Japan

Abstract

In this study, we prepare guidelines for hydrothermal-activity stage classification and evaluate the power-generation potential of geothermal wells based on a natural analog study on the hydrogeological and thermal structures and hydrothermal-alteration minerals in a low-sulfidation epithermal deposit. As such, many high-temperature geothermal wells in Japan were classified into four hydrothermal-activity stages (early, middle, late-1, and late-2) based on the developed guidelines. In conclusion, the late-1-stage well is evaluated to supply fluids for power generation with the least economic and environmental risks. In contrast, the geothermal wells in other active stages indicate some of the concerns.