Hostname: page-component-848d4c4894-xfwgj Total loading time: 0 Render date: 2024-07-01T02:57:19.520Z Has data issue: false hasContentIssue false
  • English
  • Français

Effects of Confining Pressure on Gas and Water Permeabilities of Rocks

Published online by Cambridge University Press:  21 March 2011

M. Zhang ,
M. Takeda ,
T. Esaki ,
M. Takahashi  and
H. Endo
M. Zhang
Affiliation:
Geological Survey of Japan (Now at Research Center for Deep Geological Environments, AIST, Higashi 1-1-1, Tsukuba, Ibaraki 305-8567, JAPAN, Email: m.zhang@aist.go.jp)
M. Takeda
Affiliation:
Graduate School of Civil Engineering, Kyushu University, Fukuoka 812-8581, JAPAN
T. Esaki
Affiliation:
Graduate School of Civil Engineering, Kyushu University, Fukuoka 812-8581, JAPAN
M. Takahashi
Affiliation:
Geological Survey of Japan (Now at Research Center for Deep Geological Environments, AIST, Higashi 1-1-1, Tsukuba, Ibaraki 305-8567, JAPAN
H. Endo
Affiliation:
Geological Survey of Japan (Now at Research Center for Deep Geological Environments, AIST, Higashi 1-1-1, Tsukuba, Ibaraki 305-8567, JAPAN
Get access

Abstract

Knowledge of the permeability of hydraulically-tight rock at great depth is crucially important for the design and/or assessment of facilities associated with underground disposal of radioactive nuclear wastes. This paper presents a recently developed laboratory permeability test system capable of testing low permeability rocks either by using air as a permeant or by the transient-pulse method under high confining pressure conditions that simulate ground pressures at depths. The new system was used to test Shirahama sandstone and Inada granite, which are two types of rock widely available in Japan. To investigate the effects of heterogeneity on rock permeability, specimens cored parallel to and perpendicular to bedding for sandstone, and specimens cored in the direction perpendicular to Rift Plane, Grain Plane and Hardway Plane for granite, were used. The results of this study showed that: 1) gas permeabilities of a dried rock specimen tested by air permeation are almost the same values as water permeabilities of the same saturated rock specimen tested by the transient-pulse method; 2) the intrinsic permeabilities of Shirahama sandstone and Inada granite range from about 8.33E-16 to 7.38E-17 m2 and from 1.86E-17 to 6.94E-20 m2, respectively. They decrease monotonously with increase in effective confining pressure (defined as the difference between the confining and pore pressures), while the rate of decrease diminishes at higher confining pressures. The reduction in permeabilities is due to the closure of microcracks that control fluid flow at low confining pressures; and 3) Inada granite is a heterogeneous and isotropic material. Its hydraulic heterogeneity is more significant in Rift Plane than in Hardway and Grain Planes.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 663: Symposium – Scientific Basis for Nuclear Waste management XXIV , 2000 , 851
Copyright
Copyright © Materials Research Society 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Zhang, M. et al., Geotechnical Testing Journal, 21(1), 52–57(1998).Google Scholar
2. Brace, W. F., Walsh, J. B. and Frangos, W. T., Journal of Geophysical Research, 73(6), 2225–2236 (1968).Google Scholar
3. Zhang, M. et al., Geotechnical Testing Journal, 23(1), 91–99(2000).Google Scholar
4. Zhang, M. et al., Japan Patent P3041417(2000).Google Scholar
5. Morin, R. H., Carleton, G. B. and Poirier, S., Ground Water, 35(2), 328–338(1997).Google Scholar
6. Osborne, F. F., Economic Geology, 30(5), 540–551(1935).Google Scholar
7. Hsieh, P. A., Tracy, J. V., et al., Int. J. Rock Mech. Min. Sci. & Geomech. Abs., 18(3), 245–252 (1981).Google Scholar
8. Zhang, M. et al., Geotechnical Testing Journal, 23(1), 83–90(2000).Google Scholar