Correlation of wireline log characteristics with hydrothermal alteration and other reservoir properties of the Salton Sea and Westmorland geothermal fields, Imperial Valley, California, USA
A detailed study of wireline logs from 11 wells in the Salton Sea and Westmorland geothermal systems was undertaken in order to determine the effects of hydrothermal alteration on the response of electrical and gamma-gamma density well logs. For the Salton Sea geothermal field, definite correspondence between log responses and hydrothermal mineralogy is evident, which in turn is related to the physical properties of the rocks. Three hydrothermal and one unaltered zone can be identified from log data on shales. These are: (1) the unaltered montmorillonite zone (<100/sup 0/ to 190/sup 0/C); (2) the illite zone (100/sup 0/ to 190/sup 0/C to 230/sup 0/ to 250/sup 0/C); (3) the chlorite zone (230/sup 0/ to 250/sup 0/C to 290/sup 0/ to 300/sup 0/C); and (4) the feldspar zone (>290/sup 0/ to 300/sup 0/C). The characteristic responses on well logs by which these zones are identified result primarily from changes in clay mineralogy of the shales and increases in density with progressive hydrothermal metamorphism. In the Westmorland geothermal field, differentiating mineral zones from log responses was only partially successful. However, analyses of both well log and petrologic data for wells Landers 1 and Kalin Farms 1 suggest that the former is heating up and the latter is cooling.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 6709584
- Report Number(s):
- LA-10128-MS; ON: DE84015088
- Resource Relation:
- Other Information: Portions are illegible in microfiche products. Original copy available until stock is exhausted
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
IMPERIAL VALLEY
HYDROTHERMAL ALTERATION
WELL LOGGING
SALTON SEA GEOTHERMAL FIELD
BRINES
GAMMA-GAMMA LOGGING
ILLITE
MINERALOGY
MONTMORILLONITE
PETROGRAPHY
RESERVOIR TEMPERATURE
SALINITY
SHALES
ZONES
CALIFORNIA
CLAYS
FEDERAL REGION IX
GEOTHERMAL FIELDS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
NORTH AMERICA
RADIOACTIVITY LOGGING
ROCKS
SEDIMENTARY ROCKS
USA
Geothermal Legacy