The hydraulic and mechanical characterization of oil sand fracture
An experimental and numerical study was conducted to investigate the hydraulic and mechanical response of an oil sand fracture to a varying confining pressure. The oil sand fracture was induced in core samples along the axis of the sample using the Brazilian tensile test. A Computer Assisted Tomography (CAT) scanning analysis was performed before and during the flow tests to determine the fracture geometry as a function of confining pressure. The fracture was shown to be a variable aperture system with surface roughness and tortuosity playing an increasing role as the fracture closed under pressure. Flow tests revealed a non-linear behaviour, deviating from the cubic law and indicated the roughness effects of a natural oil sand fracture are significant. The mechanical response was similar to that of the hydraulic behaviour indicating the strong relationship between the two. The numerical study revealed that the tortuosity of the flow paths increased as the fracture closed. A two-phase flow study showed that phase interference was significant and the interface between phases has an unsteady nature. Thus, relative permeability is not a function of saturation alone.
Bibliography: p. 143-148.
Walters, D. A. (1995). The hydraulic and mechanical characterization of oil sand fracture (Unpublished master's thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/13190