Options for Geothermal Deployment: EGS, Sedimentary Basins, and Beyond

• December 4, 2009: 1:00pm - 2:00pm
• Location: 250 Sutardja Dai Hall, UC Berkeley

G. Michael Shook, Chevron ETC

Broadcast live online at mms://media.citris.berkeley.edu/webcast250, and questions can be sent via Yahoo IM to username: citrisevents.

Abstract:

A DOE goal mandated in 2005 for future US geothermal power production was 40,000 MWe by 2040, up from an existing generation capacity of 3000 MWe.  All of the current geothermal power production is from hydrothermal reservoirs, of which very few profitable sites exist.  This aggressive goal requires developing new technologies targeting other resources, including power production from sedimentary basins, engineered geothermal systems (EGS) and other novel resources.

We explore a number of studies aimed at identifying geothermal opportunities in unconventional resource bases, including development of EGS and exploiting the existing infrastructure in sedimentary basins (a non-traditional source of geothermal energy).  As a means of identifying resource potential, we define a project success as 5 MWe geothermal power production after 5 years of field production.  The single biggest hurdle that must be overcome is the need for relatively large production rates (e.g., 15,000 STB/d of water at 150°C per MWe with existing conversion technology).  These rates imply the need for highly stimulated fractured zones; however, the need for large residence times for heat transfer to the working fluid also suggests the need for tortuous flow paths between injection and extraction points.  These two needs tend to work against one another, requiring tradeoffs in EGS design.  These goals can be overcome to some degree in sedimentary systems; however, studies have shown power generation in sedimentary basins requires circulation (reinjection) of the working fluids, adding to the cost of power generation.

Results of a series of studies are presented, showing the difficulties in power generation from unconventional geothermal resources.  New ideas and technologies are reviewed that may help in achieving the DOE goal of geothermal power generation.

Biography:
Mike Shook has a MSPE from University of Texas (1988), and worked at the Idaho National Laboratory as a reservoir engineer for 17 years in the DOE geothermal program.  Shook published more than 40 papers on geothermal reservoir engineering, and acted at the Reservoir Technologies Laboratory Program manager in 2005.  His main interests in geothermal engineering are tracer interpretation methods, numerical modeling, and unconventional resource evaluation.  He has taught short courses in reservoir modeling for 15 years for the DOE (Poland), Geothermal Resources Council, and Comisión Federal de Electricidad (Mexico).

Shook left INL in 2006, moving to Chevron ETC in Houston.  He continues to support the Chevron geothermal program, teaching geothermal tracer interpretation workshops and assisting in design and interpretation of tracer tests for Chevron’s geothermal assets.