PROCEEDINGS, Thirty-Eighth Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, February 11-13, 2013 SGP-TR-198 RIFT ZONES AS A CASE STUDY FOR ADVANCING GEOTHERMAL OCCURRENCE MODELS Daniel King1,3 and Elisabet Metcalfe2,3 1AAAS Science & Technology Policy Fellow 2SRA International, Inc. 3Geothermal Technologies Office, U.S. Department of Energy 1000 Independence Ave. SW Washington, DC, 20585, USA e-mail:
[email protected] or fully characterized. If geothermal electricity ABSTRACT generation is to increase significantly in the U.S., new blind hydrothermal resources must be identified To search efficiently for blind geothermal systems, and characterized. Unfortunately, geologic structure general geographic regions must first be identified and formation data are often sparse or incomplete, based upon gross characteristics which together introducing a high level of risk to a geothermal imply favorable heat flow, fluid flow, and industry seeking blind systems. To increase the permeability. Geothermal occurrence models seek to success rate of costly exploratory drilling, upfront strategically identify those promising locations to investment in exploration and resource focus exploration efforts and investment. In so doing, characterization is necessary. An essential such models can increase the expected success rate of component of early stage exploration is a geothermal exploratory drilling, reduce risk, and attract occurrence model (e.g., Walker et al., 2005) to investment. Among the most promising tectonic provide the framework for the set of characteristics to settings for blind geothermal systems are rift zones. be sought during exploration. A broader overview of Rift zones occur where lithospheric plates are thinned the technology pathways necessary to achieve cost by tectonic extension and convection at zones of reduction through improved exploration technologies upwelling hot material.