Numerical Simulation of Microscopic Carbon Dioxide Hydrate Formation in Two-phase Flow

Carbon capture and storage (CCS) emerges as a promising technology to mitigate global warming. In Japan, potential capacity is provided by deep saline reservoirs, in which can be injected and stored. However, although the possibility is low: may leak if the caprock cracks due to natural accidents. One solution to such a leakage is considered CO
2
hydrate formation. Once CO
2
hydrate is formed, it changes the morphology of pore spaces and the permeability of sand layers can be significantly reduced. Past studies have already shown the influence of hydrate formation on the permeability of sand layers. This study showed the influence of flow on microscopic hydrate growth under various initial conditions of pressure and initial temperature. Hydrate growth within in the pore space is simulated by the phase-field method, while the two-phase flow is simulated using the Lattice Boltzmann method. Results showed that the lower the flow speed is, the more the hydrate is formed. Effective permeability change during hydrate formation was also provided.