Constitutive Law for Permeability Evolution of Sandstones During Depletion

Abstract

Abstract Permeability changes have been measured during triaxial tests performed on two sets of Vosgian sandstones. The obtained results led to the definition of a criterion in the p’-q plot (effective mean stress – deviatoric stress) for the evolution of permeability. Inside the domain defined by the criterion, the permeability change is nil or small whatever the loading path is. The results are generalized in a normalized p’*-q* plot. The normalized stresses p’*-q* were previously defined by Wong et al., and depend on the onset of grain crushing under hydrostatic loading. We suggest herein a simpler way to determine the normalizing stress. Furthermore, the experimental results are interpreted to propose an explicit law for the evolution of permeability as a function of the stress path.