Experimental investigation of the effect of compliant pores on reservoir rocks under hydrostatic and triaxial compression stress states
- Department of Civil and Architectural Engineering, University of Wyoming, Laramie, WY, USA.; DOE/OSTI
- Department of Civil and Architectural Engineering, University of Wyoming, Laramie, WY, USA.
- Department of Geology and Geophysics, University of Wyoming, Laramie, WY, USA.
- Department of Chemical Engineering, University of Wyoming, Laramie, WY, USA.
- Wyoming State Geological Survey, Laramie, WY, USA.
The presence of compliant pores in rocks is important for understanding the stress–strain behaviors under different stress conditions. This paper describes findings on the effect of compliant pores on the mechanical behavior of a reservoir sandstone under hydrostatic and triaxial compression. Laboratory experiments were conducted at reservoir temperature on Weber Sandstone samples from the Rock Springs Uplift, Wyoming. Each experiment was conducted at three sequential stages: (stage 1) increase in the confining pressure while maintaining the pore pressure, (stage 2) increase in the pore pressure while maintaining the confining pressure, and (stage 3) application of the deviatoric load to failure. The nonlinear pore pressure – volumetric strain relationship governed by compliant pores under low confining pressure changes to a linear behavior governed by stiff pores under higher confining pressure. The estimated compressibilities of the matrix material in sandstone samples are close to the typical compressibility of quartz. Because of the change in pore structures during stage 1 and stage 2 loadings, the estimated bulk compressibilities of the sandstone sample under the lowest confining pressure decrease with increasing differential pressure. The increase in crack initiation stress is limited with increasing differential pressure because of similar total crack length governed by initial compliant porosity in sandstone samples.
- Research Organization:
- Univ. of Wyoming, Laramie, WY (United States)
- Sponsoring Organization:
- USDOE Office of Fossil Energy (FE)
- DOE Contract Number:
- FE0023328
- OSTI ID:
- 1614203
- Journal Information:
- Canadian Geotechnical Journal, Journal Name: Canadian Geotechnical Journal Journal Issue: 7 Vol. 56; ISSN 0008-3674
- Publisher:
- Canadian Science Publishing
- Country of Publication:
- United States
- Language:
- English
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