Numerical simulations for sub-seabed storage of CO 2 in the form of gas hydrate on the reservoir and pore scales

Hydrate reformation may cause a blockage for the two-phase flow of gas and water in the sediment. This may lead to the flow stagnation in gas production process from hydrate and to one of the trap mechanisms against the gas leakage. Therefore, the permeability change due to the hydrate formation is the aim of this study. We are interested in the morphology of the hydrate formed in the sand sediment and this means the importance of the morphology of the gas-water two phases in the porous media, i.e. the area and curvature of the two-phase interface in the pore space of microscale particles. The hydrate formation and the relevant mass and heat transfers were numerically analyzed in a computational domain, in which sand, water, and hydrate-guest-gas were distributed. Hydrate formation experiments were also carried out using a cylindrical pressure cell. The proposed model successfully simulated the two-phase flow with and without stagnation, which is conditionally caused by hydrate formation.