Numerical simulation of heat transfer effects on methane hydrate dissociation by depressurization

摘要

The methane hydrate dissociation process is always subject to the influence of heat transfer, which may affect the distribution of core temperature and the cumulative gas production. In this study, in order to analyze the heat transfer from surrounding and the conduction and convective heat transfer effect in hydrate dissociation process, a two-dimensional axisymmetric simulator is developed to model methane hydrate dissociation in porous media by depressurization. Energy conservation, mass transport, and intrinsic kinetic reaction are included in the governing equations, which are discretized by finite difference method and are solved in the implicit pressure-explicit saturation (IMPES) method. Therefore a series of simulations are performed to study the effect of the distribution of temperature and the cumulative gas production. These result suggest that heat input from surrounding have an obviously influence on the cumulative gas production and the distribution of core temperature, but the influence will be weaker when heat input from surrounding be a suitable value. Comparing with heat convective, heat conduction plays a less important role in hydrate dissociation.