Insight into Heterogeneity Effects in Methane Hydrate Dissociation via Pore-Scale Modeling

Abstract

The production of natural gas from the gas hydrates has attracted significant attention over the last few decades. A continued challenge in gas hydrates is the estimation of the stored gas capacity. To alleviate this problem, this study uses the numerical modeling to provide insight into the distribution of hydrate in porous media and to obtain information about the application of high pressure for gas recovery. Hydrate dissociation process in porous media is modeled at the pore scale using pore network modeling by considering the uniform and non-uniform hydrate distribution. We explored the effect of gas clustering, saturation, and recovery, and their dependency on the underlying parameters including the pore size distribution, the applied pressure drops across the pore structures, and the initial hydrate saturation. We found that non-uniform hydrate distribution, larger pore sizes along with high-pressure drop, and higher initial hydrate saturations enhanced gas release. Additionally, our results confirmed the findings of the previous studies using 2D networks which studied pressure drop during hydrate dissociation in reservoirs.