(GP/GT) for Additional Water Supply in the Lower Rio Grande

THE GEOPRESSURED RESOURCE
Geopressured resources vary considerably from hydrothermal resources.
The contained gases, and higher well pressures contained in geopressured
resources can significantly increase the opportunities and methods of
application that can be developed. This section provides information
about what the geopressured resource is, where it may be found, and
applicable salient features and considerations.
Figure S displays the distribution of known hydrothermal resources in
the United States. It should be noted that the present state of
knowledge of geothermal resources of all types is very limited. It is
known with reasonable certainty, that there are many more low-temperature
19S'F (90'C) hydrothermal-geothermal occurrences than there are
high-temperature 300'F (lS0'C) areas (Wright and Culver, 1989).
Geopressured-geothermal resources are a normal phase of basin
evolution and are found in many locations throughout the U.S. (Figure 6)
and the world. Geopressured resources have three energy forms: thermal,
hydraulic, and methane gas. These three forms of energy can be converted
to higher value forms of energy using the available technologies. The
thermal energy can be converted to electricity using an organic Rankine
cycle generator. The hydraulic energy can be converted to electricity
with a hydraulic turbine. Dissolved methane gas can be separated and
sold, burned, compressed, liquefied, or converted to methanol or to
electricity by fueling a turbine (Negus-de Wys, 1989).
Geopressured resources normally exist between 12,000 to 20,000 ft
below the surface. Flow rates can vary between 10,000 to 40,000 bpd.
Temperatures will range from 273 to SOO'F. Bottom hole pressures vary
from 12,000 to 18,500 lb/in. 2 absolute (psia). Salinity will be present
in the amount of 20,000 to 200,000 mg/L. Gas content will vary between 23
to 100 standard cubic feet (scf) per barrel of fluid (Negus-de Wys,
1989).
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