Abstract
Permeability is important for considering the rate and extent of water-rock interaction in the Earth ranging from shallow parts to deep crust. It is an open question what pore structure (e.g., porosity, pore size, pore shape) controls the permeability. In this study, we determined the “characteristic maximum pore-throat size” by measuring the pressure at which gas initially penetrates a water-saturated sample (water-expulsion method). The characteristic maximum pore-throat size is strongly correlated with the permeability for various geologic media, showing that the characteristic pore-throat mainly controls the permeability.