Role of cracks in progressive permeability reduction during flow of heated aqueous fluids through granite

Journal Article · Tue Jun 10 04:00:00 EDT 1986 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JB091iB07p07517· OSTI ID:5509180

Vaughan, P J; Moore, D E; Morrow, C A; Byerlee, J D

Permeability was measured continuously during an experiment in which a heated, aqueous fluid was pumped through a cylindrical sample of Westerly Granite. Fluid flowed radially outward from an axial borehole down a temperature gradient to the outer edge of the sample. The fluid temperature in the borehole was maintained at 300 /sup 0/C, while a pore pressure difference of 0.5 MPa provided the driving force for fluid flow. Permeability decreased by a factor of 25 during the 2-week experiment. Scanning electron microscope examination of this altered sample indicates that about half of the grain boundaries involving quartz are cracked or were cracked at some time during the experiment and now contain a filling material. Grain boundaries between the two feldspars are closed in the starting material and in all areas of the altered sample that were examined.

• Research Organization: U. S. Geological Survey, Menlo Park, California
• OSTI ID: 5509180
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 91:B7; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
152003* -- Geothermal Data & Theory-- Rock-Water-Gas Interactions
CRACKS
CRYSTAL STRUCTURE
GRANITES
HIGH TEMPERATURE
IGNEOUS ROCKS
MICROSTRUCTURE
PERMEABILITY
PLUTONIC ROCKS
POROSITY
PRECIPITATION
ROCK-FLUID INTERACTIONS
ROCKS
SEPARATION PROCESSES
TEMPERATURE GRADIENTS