Numerical Study on Dissociation of Gas Hydrate and Its Sensitivity to Physical Parameters

The natural gas hydrate resource is tremendous. How to utilize the gas from hydrates safely is researchers' concern. In this paper, a one-dimensional model is developed to simulate the hydrate dissociation by depressurization in hydrate-bearing porous medium. This model can be used to explain the effects of the flow of multiphase fluids, the endothermic process of hydrate dissociation, the variation of permeability, the convection and conduction on the hydrate dissociation. Numerical results show that the hydrate dissociation can be divided into three stages: a rapid dissociation stage mainly governed by hydrate dissociation kinetics after an initially slow dissociation stage governed mainly by flow, and finally a slow dissociation stage. Moreover, a numerical approach of sensitivity analysis of physical parameters is proposed, with which the quantitative effect of all the parameters on hydrate dissociation can be evaluated conveniently.