Challenges in Geothermal Development Geological Investigation and Well Targeting in Japan

This book provides a comprehensive characterization of high-temperature geothermal fields worldwide, encompassing diverse geological settings such as extensional and contractional tectonics, silicic and mafic crustal regions, hypersaline and low-salinity fluid environments, and both brittle and ductile lithospheric layers. It also details current geothermal exploration and development efforts in Japan.

Emerging exploration technologies, including Full-waveform Inversion (FWI), Distributed Temperature Sensing (DTS), and Distributed Acoustic Sensing (DAS), are introduced and discussed in the context of their practical applications. A central challenge in geothermal development remains the accurate identification of viable targets for production and reinjection wells, as exploratory drilling entails significant costs. Accordingly, this book places special emphasis on target identification strategies, setting it apart from other works in the field.

While global in scope, this book primarily focuses on geothermal development in Japan and features field-based case studies related to well targeting. Authored and reviewed by experienced geothermal engineers, it serves as a valuable resource for professionals engaged in geothermal exploration and reservoir engineering.

Overview of High-Temperature Geothermal Systems in the World.- Tectonic Backgrounds and Advances of Geothermal Developments in Japan.- High-Temperature Hydrothermal Systems Inducd from Shallow-Depth Magma.- Fundamentals of the Brittle–Ductile Transition in the Crust.- General Exploration Methods Applied for Geothermal Development.- Case studies I: High- and Ultra-High-Temperature Geothermal Fields in Japan and the World.- Geothermal Exploration Using the Optical Fiber Sensing: Distributed Temperature Sensing (DTS) Technology.- Latest Geothermal Exploration and Development.- Geothermal Systems and Geothermal Reservoirs.- Understanding of High-Temperature Zones in Geothermal Reservoirs.- Understanding of High Permeable Zones in Geothermal Reservoir.- Production Well Targeting Based on Geological Analyses.- Reinjection Wells.- Case studies II: Well Targeting Field Examples in Japan.

Junzo Kasahara received his B.S., M.S., and D.Sc. degrees in geophysics from Nagoya University in 1965, 1967, and 1970, respectively. Between 1970–1986 and 1988–2004, he was an assistant, associate, and full professor at the University of Tokyo, where he worked on marine seismology. During 1974–1976 and in 1979, he was a visiting associate professor at the University of Hawaii. In 1986, he joined Schlumberger Japan as a design manager for seismic interpretation and logging tools. He has published three books with the University of Tokyo Press during his academic work and has been named a professor emeritus of the University of Tokyo. He is the chief editor of “Active Geophysical Monitoring 1^st and 2^nd editions” by Elsevier Pub. He acts as an editorial board member of “Advances in Geological Science” of Springer-Nature. In 2004, he joined Tono Geoscience Center as a senior researcher, where he worked on the Accurately Controlled Rotary Seismic Sources (ACROSS) project. Between 2004 and 2008, he served to redefine the Japan Continental Shelf to extend it geologically. Currently he is working on a geographical exploration and DAS project funded by the NEDO (New Energy and Industrial Technology Development Organization).

Ko Sato received his Dr.Sci. degree in geology from Tohoku University in 1980. He is a technical adviser to geothermal development at Socio Engineering Co., Ltd. He is a geothermal expert in geological investigation and comprehensive survey analyses, and he is a supervisor of well drilling projects. He supervised the production well drilling of the deep geothermal resource project in Kakkonda, Japan, in the New Energy and Industrial Technology Development Organization (NEDO) project from 1993 to 1998. He researched the feasibility study of the La Primavera geothermal field in Mexico for geothermal resources through the Japan International Cooperation Agency (JICA) project from 1985 to 1989. He has engaged in the construction of geothermal power stations such as in Matsukawa, Kakkonda, and Mori from 1969 to 2001. He has published books in Japanese geothermal geology and production well targets, Japan, in 2019 and 2022.

Hirofumi Muraoka is a guest researcher at Hirosaki University and a part-time advisor at Nippon Koei. He received his B.S. in geology from Yamaguchi University in 1975 and M.S. and Ph.D. in petrology from Hiroshima University in 1977 and 1989, respectively. He worked on geothermal research at the Geological Survey of Japan and its successor, the National Institute of Advanced Industrial Science and Technology (AIST), from 1978 to 2010. He was a professor and director at the North Japan Research Institute for Sustainable Energy (NJRISE), Hirosaki University, from 2010 to 2018 and 2013 to 2018, respectively. He was the representative of Japan in the Geothermal Implementing Agreement (GIA), the International Energy Agency (IEA) from 2005 to 2012. He was the lead author of the special report Renewable Energy Sources and Climate Change Mitigation (Cambridge University Press, 2012)