Open AccessEffect of stress on the microstructure of a graywacke sandstone from the site of the Rio Blanco gas-stimulation experiment
Author(s) -
Lori Dengler
Publication year - 1975
Language(s) - English
Resource type - Reports
DOI - 10.2172/4129709
Subject(s) - geology , permeability (electromagnetism) , structural basin , mineralogy , hydraulic fracturing , geotechnical engineering , geomorphology , chemistry , biochemistry , membrane
Project Rio Blanco was designed to increase rock permeability in an existing gas reservoir by fracturing the rock with a vertical array of three simultaneous nuclear explosions. The project site was CER Geonuclear hole RB-E- 01, Section 14, T35, R98W, Rio Blanco County, in the Piceance Creek Basin of northwest Colorado. The most essential part of this project was to produce fracturing in, and thereby to increase the permeability of, the reservoir rock. This report contains the results of optical and scanning electron microscope (SEM) studies done on unstressed and laboratory-stressed samples of graywacke sandstone from the 6458-ft level of the emplacement hole. Laboratory-stressed samples were from uniaxial-stress and uniaxial-strain tests made as part of equation-of-state measurements used to provide input parameters for preshot code calculations. (auth