In situ heat transfer in man-made geothermal energy reservoirs

Conference · Tue Jan 01 00:00:00 EST 1980

OSTI ID:5303877

Murphy, H D; Tester, J W; Grigsby, C O; Potter, R M

Two hot dry rock geothermal energy reservoirs were created by hydraulic fracturing of Precambrian granitic rock on the west flank of the Valles Caldera, a dormant volcanic complex, in the Jemez Mountains of northern New Mexico. Heat was extracted in a closed-loop mode of operation, injecting water into one well and extracting the heated water from a separate production well. The first reservoir was produced by fracturing the injection well at a depth of 2.75 km (9020 ft) where the indigenous rock temperature was 185/sup 0/C. The relatively rapid thermal drawdown of the water produced from the first reservoir, 100/sup 0/C in 74 days, indicated that its effective fracture radius was about 60 m (200 ft). Average thermal power extracted was 4 MW. A second, larger reservoir was created by refracturing the injection well 180 m (600 ft) deeper. Downhole measurements of the water temperature at the reservoir outlet as well as temperatures inferred from chemical geothermometry showed that the thermal drawdown of this reservoir was negligible; the effective heat transfer area of the new reservoir must be at least 45,000 m/sup 2/ (480,000 ft/sup 2/), nearly six times larger than the first reservoir. In addition reservoir residence time studies employing visible dye tracers indicated that the mean volume of the second reservoir is nine times larger. Other measurements showed that flow impedances were low, downhole water losses from these reservoirs should be manageable, that the geochemistry of the produced water was essentially benign, with no scaling problems apparent, and that the level of induced seismic activity was insignificantly small.

• Research Organization: Los Alamos Scientific Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5303877
• Report Number(s): LA-UR-80-454; CONF-800723-17
• Resource Relation: Conference: 19. national heat transfer conference, Orlando, FL, USA, 27 Jul 1980
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
HOT-DRY-ROCK SYSTEMS
HEAT TRANSFER
HYDRAULIC FRACTURING
DRAWDOWN
GEOTHERMAL WELLS
GEOTHERMOMETRY
HEAT EXTRACTION
IMPEDANCE
INJECTION WELLS
JEMEZ MOUNTAINS
RESERVOIR TEMPERATURE
TESTING
VOLCANIC REGIONS
COMMINUTION
ENERGY TRANSFER
FRACTURING
GEOTHERMAL SYSTEMS
MOUNTAINS
NEW MEXICO
NORTH AMERICA
SOUTHWEST REGION
USA
WELLS
Geothermal Legacy
150906* - Geothermal Engineering- Reservoir Stimulation & Extraction Technology