Assessing the role of ancient and active geothermal systems in oil-reservoir evolution in the eastern Basin and Range province, western USA. Annual progress report, June 1, 1992--May 31, 1993
Results of our research on the oil fields of the Basin and Range province of the western USA continue to support the following concept: Convecting, moderate-temperature geothermal systems in this region have fostered and in some cases critically influenced the generation, migration, and entrapment of oil. At one Basin-Range field (Grant Canyon), oil-bearing and aqueous fluid inclusions in late-stage hydrothermal quartz were entrapped at temperatures comparable to those now prevailing at reservoir depths (120--130{degrees}C); apparent salinities of the aqueous varieties match closely the actual salinity of the modern, dilute oil-field waters. The inclusion-bearing quartz has the oxygen-isotopic signature for precipitation of the mineral at contemporary temperatures from modern reservoir waters. Measured and fluid-inclusion temperatures define near-coincident isothermal profiles through the oil-reservoir interval, a phenomenon suggesting ongoing heat and mass transfer. These findings are consistent with a model whereby a still-active, convectively circulating, meteoric-hydrothermal system: (1) enhanced porosity in the reservoir rock through dissolution of carbonate; (2) hydrothermally sealed reservoir margins; (3) transported oil to the reservoirs from a deep source of unknown size and configuration; and (4) possibly accelerated source-rock maturation through an increase in the local thermal budget. Grant Canyon and other Basin-Range oil fields are similar to the oil-bearing, Carlin-type, sediment-hosted, disseminated gold deposits of the nearby Alligator Ridge district. The oil fields could represent either weakly mineralized analogues of these deposits, or perhaps an incipient phase in their evolution.
- Research Organization:
- Utah Univ. Research Inst., Salt Lake City, UT (United States). Earth Science Lab.
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG02-90ER14133
- OSTI ID:
- 10169872
- Report Number(s):
- DOE/ER/14133-2; ESL-93032-TR; ON: DE93018319
- Resource Relation:
- Other Information: PBD: 1 Jul 1993
- Country of Publication:
- United States
- Language:
- English
Similar Records
The role of active and ancient geothermal systems in evolution of Grant Canyon oil field, Railroad Valley, Nye County, Nevada
Hydrothermal speleogenesis in the Eastern Basin and Range Province - Implications for Petroleum and precious-metal exploration
Related Subjects
15 GEOTHERMAL ENERGY
PETROLEUM DEPOSITS
ORIGIN
PROGRESS REPORT
GEOTHERMAL SYSTEMS
NEVADA
SALINITY
MATHEMATICAL MODELS
MINERALIZATION
METEORIC WATER
Geothermal Legacy
020200
150100
150200
RESERVES, GEOLOGY, AND EXPLORATION
RESOURCES AND AVAILABILITY
GEOLOGY AND HYDROLOGY OF GEOTHERMAL SYSTEMS