Geopressured-Geothermal Research Program: An Overview

Conference · Sat Apr 01 04:00:00 EST 1989

OSTI ID:896394

Fortuna, Raymond; Jelacic, Allan

The geopressured-geothermal resource consists of deeply buried reservoirs of hot brine, under abnormally high pressures, that contain dissolved methane. Geopressured brine reservoirs with pressures approaching the lithostatic load are known to occur both onshore and offshore beneath the Gulf of Mexico coast, along the Pacific west coast, in Appalachia, as well as in deep sedimentary basins elsewhere in the United States. The Department of Energy (DOE) has concentrated its research on the northern Gulf of Mexico sedimentary basin (Figure 1) which consists largely of Tertiary interbedded sandstones and shales deposited in alternating deltaic, fluvial, and marine environments. Thorsen (1964) and Norwood and Holland (1974) describe three generalized depositional facies in sedimentary beds of the Gulf Coast Geosyncline (Figure 2 ): (1) a massive sandstone facies in which sandstone constitutes 50 percent o r more of the sedimentary volume; (2) an alternating sandstone and shale facies in which sandstone constitutes 15 to 35 percent of the sedimentary volume. (3) a massive shale facies in which sandstone constitutes 15 percent or less of the sedimentary volume. In general, at any given location the volume of sandstone decreases with increasing depth. The datum of higher-than-normal fluid pressures is associated with the alternating sandstone and shale facies and the massive shale facies. Faulting and salt tectonics have complicated the depositional patterns and influenced the distribution of geopressured reservoirs (Wallace et a1 1978). The sandstones in the alternating sandstone and shale facies have the greatest potential for geopressured-geothermal energy development. Due to the insulating effect of surrounding shales, temperatures of the geopressured-geothermal brines typically range from 250 F to over 350 F, and under prevailing temperature, pressure, and salinity conditions, the brine contains 20 or more cubic feet of methane per barrel. Wallace et al (1978) estimated the geopressured-geothermal energy in Gulf Coast sandstone pore fluids to a depth of 22,500 feet to be 5,700 TCF of methane and 11,000 quads of thermal energy.

• Research Organization: USDOE
• Sponsoring Organization: USDOE - Office of Fossil Energy (FE)
• OSTI ID: 896394
• Report Number(s): DOE/METC-89/6103
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
APPALACHIAN MOUNTAINS
BRINES
CONTRACTORS
DISTRIBUTION
GULF OF MEXICO
METHANE
NATURAL GAS
RESEARCH PROGRAMS
SALINITY
SANDSTONES
SEDIMENTARY BASINS
SHALES
TECTONICS
US GULF COAST