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Title: Conceptual Schematic Geologic Cross-Sections of the Geysers Steam Field

Conference ·
OSTI ID:887156

While formerly studied in terms of ancient Franciscan stratigraphy, The Geysers Steam Field now offers new views and interpretations on the deeper structure and importance of the lithocap, main metagraywacke, and felsic intrusive basement units with respect to the huge fractured reservoir. The Big Sulphur Creek enhanced tectonic disruption area provides the best situation for shallow felsite injection, shallow reservoir top, metasomatism transformation, and profound fracture permeability. Steam cells commonly extend to great depths and laterally drop off sharply, with relatively flat lateral continuance in some resource areas. Injectate ponding may offer a third fluid interface for reservoir steam reserves. A possible boiled down residuum of complex evaporates and hematite has been viewed in one area of the field where the reservoir (proper) bottom was encountered. Such a deposit may exist along all reservoir cell(s) bottoms, where in numerous cases the reservoir proper has been seen to pass into a somewhat mysterious ultra-superheated reservoir.

Research Organization:
Diamond Shamrock Thermal Power Co., Santa Rosa, CA.
Sponsoring Organization:
USDOE
DOE Contract Number:
AS03-80SF11459; AS07-84ID12529
OSTI ID:
887156
Report Number(s):
SGP-TR-93-37; TRN: US200618%%164
Resource Relation:
Conference: Proceedings, Eleventh Workshop Geothermal Reservoir Engineering, Stanford University, Stanford, California, January 21-23, 1986
Country of Publication:
United States
Language:
English