Geothermal resources of the Northern Gulf of Mexico basin

Journal Article · Thu Jan 01 04:00:00 EST 1970 · Geothermics, no. Special is, pp. 14-26

DOI:https://doi.org/10.1016/0375-6505(70)90002-7· OSTI ID:4331640

Jones, P H

Published geothermal gradient maps for the northern Gulf of Mexico basin indicate little or no potential for the development of geothermal resources. Results of deep drilling from 4000 to 7000 meters or more during the past decade however, define very sharp increases in geothermal gradient that are associated with the occurence of abnormally high interstitial fluid pressure. Bounded by regional growth faults along the landward margin of the Gulf Basin, the geopressured zone extends some 1300 km from the Rio Grande to the mouth of the Mississippi River. Gulfward, it extends to an unknown distance across the Continental Shelf. Within geopressured deposits, geothermal gradients range upwards to 100 deg C/km, being greatest within and immediately below the depth interval in which the maximum pressure gradient change occurs. The 120 deg C isogeotherm ranges from about 2500 to 5000 m below sea level, and conforms in a general way with depth of occurrence of the top of the geopressured zone. Measured geostatic ratios range upward to 0.97: the maximuni observed temperature is 273 deg C, at a depth of 5859 m. Dehydration of montmorillonite, which comprises 60 to 80% of clay deposited in the Northern Gulf Basin during the Neogene, occurs at depths where temperature exceeds about 80 deg C, and is generally complete at depths where temperature exceeds 120 deg C. This process converts intracrystalline and bound water to free pore water, the volume produced being roughly equivalent to half the volume of montmorillonite so altered, Produced water is fresh, and has low viscosity and density. Sand-bed aquifers of deltaic, longshore, or marine origin form excellent avenues for drainage of geopressured deposits by wells, each of which may yield 10,000 m/sup 3/ or more of superheated water per day from reservoirs having pressures up to 1000 bars at depths greater than 5000 m. (46 references) (auth)

• Research Organization: Geological Survey, Baton Rouge, LA
• Sponsoring Organization: USDOE
• NSA Number: NSA-29-020450
• OSTI ID: 4331640
• Journal Information: Geothermics, no. Special is, pp. 14-26, Journal Name: Geothermics, no. Special is, pp. 14-26; ISSN GTMCA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

*GEOTHERMAL ENERGY-- GULF OF MEXICO
CLAYS
ENERGY SOURCES
GEOLOGY
MAPS
MONTMORILLONITE
N80200* --Energy Utilization & Economics
REGIONAL ANALYSIS
SUPERHEATING
WATER