Capillary pressure, relative permeability and wettability at critically-low saturated porous media (CRISP)

A standard equation for predicting how fluids move through porous rocks breaks down when the fluids are barely present—at the point where one fluid is reduced to isolated droplets or films. This matters because engineers rely on these equations to design systems for storing hydrogen underground, trapping carbon dioxide in rock formations, or predicting how water evaporates from soil. The equations were developed for conditions where both fluids (say, water and gas) flow freely. But at the critical low saturations that occur in real storage sites—where gas is injected into a nearly water-filled rock, or water evaporates to a thin film—the equations no longer describe what physically happens. The researchers will measure capillary pressure, relative permeability, and wettability directly at these low saturations, using experiments that mimic realistic subsurface conditions. If successful, the work will provide the first reliable data and models for fluid behaviour at the edge of saturation. This could improve predictions for hydrogen storage, CO₂ sequestration, and soil moisture dynamics. The project is fundamental science—it addresses a gap in the physical theory of multiphase flow—but its outputs are directly applicable to clean energy infrastructure that depends on accurate subsurface engineering.