The Impacts of Drilling and Reservoir Technology Advances on EGS Exploitation

Abstract

The publication of “The Future of Geothermal Energy” in the fall of 2006 brought renewed interest and focus to work on Engineered Geothermal Systems (EGS) in the U.S. The magnitude of the resource, coupled with its ability to provide baseload electric power and recent technical advances achieved in field experiments internationally, have increased awareness of the potential of geothermal energy in the U.S. The U.S. Congress authorized legislation to support an ambitious national geothermal energy program as part of the recent omnibus energy bill (HR 6). An important cost component of an EGS project is drilling costs. As the quality of an EGS resource declines, drilling costs dominate the total capital investment. In this paper we explore the effects of resource quality, reservoir performance, and drilling costs on EGS economics to identify areas that could benefit from intensified R&D. The parameter space examined includes—drilling costs as a function of depth, average temperature gradient, production well flow rate, and the impacts of drilling technology innovation.