Analytical Modelling of Gas Hydrates in Porous Media

Abstract

A mathematical model is presented to predict the formation of gas hydrates in porous media under various boundary conditions. The new mathematical modeling framework is based on coupling the analytical pore network approach (APNA) and equation proposed by De La Fuente et al. [1]. Further, we also integrate thermodynamic models to capture the phase boundary at which the formation of gas hydrates takes place. The proposed analytical framework is a set of equations that are computationally inexpensive to solve, allowing us to predict the formation of gas hydrates in complex porous media. Complete governing equations are provided, and the method is described in detail to permit readers to replicate all results. To demonstrate the formation of hydrates in porous media, we analyzed the saturation of hydrates in porous media with different properties. Our model shows that the hydrate formation rate is positively related to the porous media's pore size. The hydrates were found to be preferably formed in the porous media composed of relatively larger pores, which could be attributed to the weak capillary forces resisting the formation of hydrates in porous media. The novelty of the new analytical model is the ability to predict the gas hydrates formation in porous media in a reasonable time using standard engineering computers. Furthermore, the model can aid in the estimation of natural gas hydrate reservoirs, which offer the avenue for effective methane recovery from the vast natural gas hydrate reserves in continental margins.