Investigating the permeability evolution of artificial rock during ductile and brittle deformation under pressurized flow

The injection of geothermal energy, CO 2 sequestration, and hydrogen storage all involve pressurized fluid flow through porous rock, which can cause material deformation and fracture. Despite the widespread use of these industrial methods, there is a lack of experimental data on the interplay between pore pressure rise, deformation, and permeability changes in real rock. To address this gap, this study developed an artificial rock material that can be deformed and fractured under low pressures. By controlling the porosity, permeability, and strength of the material during sintering, it is possible to mimic various rock types. The artificial rock was designed to accommodate radial flow and deformation, enabling tracking of deformation by monitoring the flux and driving pressure, and thus calculating permeability changes under various pressure conditions. The study examined the impact of both ductile and brittle deformation on permeability during pressurized flow, a model adjusted to this scenario. Direct quantification of the strain and permeability shows that there is a transition between dilating, brittle, strain to ductile compaction, in a localized way. This study links pressurized flow, rock formation, permeability, and ductile-to-brittle deformation, thereby constraining risk assessment for hydrogen storage and CO 2 sequestration.