Energy extraction characteristics of hot dry rock geothermal systems

Conference · Sat Jan 01 04:00:00 EST 1977

OSTI ID:7310729

Tester, J W; Smith, M C

The LASL Hot Dry Rock Geothermal Energy Project is investigating methods to extract energy at useful temperatures and rates from naturally heated crustal rock in locations where the rock does not spontaneously yield natural steam or hot water at a rate sufficient to support commercial utilization. Several concepts are discussed for application to low and high permeability formations. The method being investigated first is intended for use in formations of low initial permeability. It involves producing a circulation system within the hot rock by hydraulic fracturing to create a large crack connecting two drilled holes, then operating the system as a closed pressurized-water heat-extration loop. With the best input assumptions that present knowledge provides, the fluid-flow and heat-exchange calculations indicate that unpumped (buoyant) circulation through a large hydraulic fracture can maintain a commercially useful rate of heat extraction throughout a usefully long system life. With a power cycle designed for the temperature of the fluid produced, total capital investment and generating costs are estimated to be at least competitive with those of fossil-fuel-fired and nuclear electric plants. This paper discusses the potential of the hot dry rock resource, various heat extraction concepts, prediction of reservoir performance, and economic factors, and summarizes recent progress in the LASL field program.

• Research Organization: Los Alamos Scientific Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 7310729
• Report Number(s): LA-UR-77-1298; CONF-770804-6
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150906* -- Geothermal Engineering-- Reservoir Stimulation & Extraction Technology
COMMINUTION
CRACKS
ECONOMICS
ENERGY TRANSFER
FLUID FLOW
FRACTURING
GEOTHERMAL SYSTEMS
Geothermal Legacy
HEAT EXTRACTION
HEAT TRANSFER
HOT-DRY-ROCK SYSTEMS
HYDRAULIC FRACTURING
PERMEABILITY
RESERVOIR ROCK
ROCKS
THERMODYNAMIC CYCLES