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U.S. Department of Energy
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Porosity of coastal deltaic sandstones, Cerro Prieto geothermal field, Baja California, Mexico

Conference ·
OSTI ID:6990019
Core porosity values for sandstones and density log-derived porosities for sandstone-siltstone-shale sequences indicate a range from less than 1% to 40% at the Cerro Prieto geothermal field, Baja California, Mexico. Mean porosity values indicate that a general trend of decreasing porosities with increasing depth from 35% at 600 m to 10% at 2300 m is complicated by the 15 to 30% porosities in the 350/sup 0/C hot water zone at about 2700 m depth. Scanning electron microscopy documents secondary dissolution porosity, mineral overgrowths, and abundant clay minerals. Core permeability ranges from 0.1 to 1000 millidarcies for the more than 50 cores studied. The porosity variability indicates that geothermal systems provide an ideal setting for testing concepts of dissolution porosity and increased secondary dissolution permeability that could be useful for nuclear waste storage as well as petroleum reservoir engineering.
Research Organization:
Lawrence Berkeley Lab., CA (USA)
DOE Contract Number:
AC03-76SF00098
OSTI ID:
6990019
Report Number(s):
LBL-17650; CONF-840809-14; ON: DE84012249
Country of Publication:
United States
Language:
English