An extended Kozeny-Carman framework for the water permeability of saturated hydrate-bearing sediments

Permeability is a critical parameter that governs the fluid migration, sediment deformation, and heat transfer in hydrate-bearing sediments. To date, existing theoretical models capable of capturing water permeability variations with hydrate saturation often rely on empirical fitting or involve parameters that are challenging to determine experimentally. Based on the assumption of the pore habits of hydrates, a new Kozeny-Carman-based model is proposed to predict the normalized water permeability of saturated hydrate-bearing sediments without using any empirical parameters. The developed model is successfully validated using the published experimental data. Besides, the model is further improved by considering the change in tortuosity or water saturation of hydrate-bearing sediments, so that the normalized water permeability of consolidated or unsaturated hydrate-bearing sediments can be reasonably predicted. The proposed model in this study can be used to predict the normalized water permeability of saturated hydrate-bearing sediments using the known hydrate saturation Sh, void ratio for bound water ei, and total void ratio et.