Numerical Simulation of the Sumikawa Geothermal Field in the Natural State

Abstract

This paper presents some results from a numerical simulation study of the natural state of the liquiddominated high-temperature Sumikawa geothermal prospect (Pritchett et. al., 1989). Sumikawa is located in the Hachimantai volcanic zone of the Sengan thermal area in northern Honshu, Japan. Exploratory studies have been in progress at Sumikawa since 1981 by Mitsubishi Materials Corporation (MMC) and Mitsubishi Gas Chemical Corporation (MGC); this comprehensive program incorporates a variety of geochemical and geophysical surveys and an extensive preliminary drilling investigation (now exceeding sixteen wells). The drilling program has revealed a complex geological structure and has made possible a very thorough pressure-transient testing program involving both single-well and long-term interference tests. These exploratory studies have been carried out jointly by MMC and NED0 (the New Energy and Industrial Technology Development Organization, an agency of the Japanese government).