A chemo-thermo-mechanically coupled numerical simulation of the subsurface ground deformations due to methane hydrate dissociation

In order to predict ground deformations due to the dissociation of methane hydrates, we have developed a simulation method based on a chemo-thermo-mechanically coupled analysis. Within this method, the phase change from hydrates to fluids, the flow of pore water and gas, the mechanical behavior of the solid skeleton, and heat transfer can all be simultaneously solved. The numerical method is based on the finite element method using an updated Lagrangian formulation. Applying the proposed framework, we have numerically analyzed the dissociation process that occurs in the heating and depressurizing methods of natural gas production. It has been predicted that ground deformation is caused by the generation of water and gas during the dissociation process.