Characterization of hydraulic permeability and pore-size distribution of methane hydrate-bearing sediment using proton nuclear magnetic resonance measurement

A proton nuclear magnetic resonance (NMR) system combined with a permeability measurement system has been used to clarify the relation between permeability and a methane-hydrate saturation in methane-hydrate-bearing sediment with regard to effective pore-size distribution. Pore-size distributions of sediments have been calculated using the relaxation time distribution of NMR-T₂. Two different laboratory methods for growing gas hydrate in sediment cores have been used to determine the relationship between hydrate saturation and permeability: a conventional approach called the connate water method, and a dissolved-gas method. The 2 methods produced different permeability and pore-size distribution of sediment.