Reaction Kinetic Characteristics and Model of Methane Hydrate Formation in Porous Media

作者：Liang Zhang, Sudan Xu, Xin Li, Yin Zhang, Ruohan Yang, Qian Ouyang, Shaoran Ren · 发表于：Energy & Fuels · 年份：2017 · DOI：10.1021/acs.energyfuels.7b00958 · 被引用次数：34 · 研究领域：Methane Hydrates and Related Phenomena、Atmospheric and Environmental Gas Dynamics、Hydrocarbon exploration and reservoir analysis

Most of the natural gas hydrates on Earth are buried in shallow formations under deep water. Comprehensively understanding the reaction kinetic characteristics of gas hydrate in porous media is very beneficial to the deep exploration of the hydrate accumulation in nature. In this paper, the formation process of CH 4 hydrate in porous media was simulated physically, using a reactor that is operating at high pressure and low temperature. The hydrate phase equilibrium and reaction kinetic characteristics at different temperatures, pressures, sand grain sizes, and clay contents were assessed. Based on the determination of relevant hydrate kinetic parameters, a novel mixing-flux hydrate reaction model was proposed, which can be used for numerical simulation of gas hydrate accumulation. The experimental results show that the porous media can make the phase equilibrium of CH 4 hydrate shift to the right under the capillary effects on the gas and hydrate phases. Low temperature and high pressure can provide a large driving force for hydrate formation, but large clay content and small sand grain size usually give a negative effect on the CH 4 transfer in the porous media. It often leads to a slow hydrate formation rate and hard distinction of pressure drop between hydrate nucleation and growth stages. Based on the experimental results, the hydrate nucleation kinetic parameters were regressed, and the activation energy ( E a ), as well as the reaction frequency factor ( k fo ), of hydr...