Brittle faulting and permeability evolution: Hydromechanical measurement, microstructural observation, and network modeling

摘要: Dilatancy is universally observed as a precursor of brittle faulting in geomaterials. Laboratory data on permeability triaxially compressed rocks indicate that its evolution during deformation can be very complex. In low-porosity crystalline rocks, enhancement generally dilatancy and positive correlation exists between porosity. porous siliciclastic experimental show the would actually decrease while pore space dilates sample stressed to failure. With constraints from microstructural observations, percolation network models provide physical insights into interplay stress-induced cracking pre-existing structure induces such negative porosity changes. The laboratory suggest tectonic seismogenic system located rock potentially induce massive fluid discharge along conduits, which may localized high-permeability heterogeneity damage zone. However, it unlikely formations shear displacement gouge zones conduits for fault zones. To emphasize fundamental differences compact rock, separate deformation-permeability maps stress are proposed conceptual evolution. region active faulting, loading path typically involves variations deviatoric stresses, well mean pressure. important insight stress, pressure relation transport. Hydromechanical parameters control generation maintenance excess also identified.