Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Geologic research at The Geysers

Conference ·
OSTI ID:450628
; ;  [1]
  1. Univ. of Utah, Salt Lake City, UT (United States)

Geologic research at The Geysers vapor-dominated geothermal field during the past year has yielded new information on the nature of steam-reservoir porosity and permeability; the origin of the caprock; mechanisms of lateral sealing; the evolution of The Geysers hydrothermal system; and specific reservoir controls in and immediately above {open_quotes}the felsite{close_quotes}, an hypabyssal, batholith-sized pluton largely responsible for The Geysers` existence. Our research has shown that (1) fluid conduits above the felsite may be dominantly vuggy, high-angle hydrothermal veins; (2) latest-stage hydrothermal calcite in such veins may seal them at the margins of the steam reservoir; mixed-layer clays are probably the corresponding seals in the caprock; (3) steam entries in the felsite are concentrated along the top of the youngest intrusive phase in the pluton - a 1 m.y.-old granodiorite; (4) steam entries in the felsite show a negative correlation with massive borosilicate enrichments.

Research Organization:
University of Utah, Salt Lake City, UT
Sponsoring Organization:
USDOE
OSTI ID:
450628
Report Number(s):
DOE/EE--0106; CONF-9604116--22; ON: DE96015206
Country of Publication:
United States
Language:
English