Abstract: The reserves of natural gas hydrate determine its potential commercial development value. Combining the composition of seabed sediments and the seabed environment, the experiments were conducted to study the effect of calcium carbonate as a porous medium and sodium dodecyl sulfate (SDS) on methane hydrate formation under the conditions of 2 ℃ and 6.08 MPa and its mechanism was analyzed. The results show that the gas storage effect and gas storage rate of the two synergistic systems are better than pure SDS solutions. Changes in the particle size of calcium carbonate could change the amount of hydrate formation and gas storage effect, of which 1 mm calcium carbonate has the best gas storage effect. The synergistic system greatly shortens the induction period of hydrates and accelerates the rate of hydrate nucleation. The promotion effect of the synergistic system is reflected in the promotion effect of SDS and the promotion effect of calcium carbonate surface characteristics and particle size changes and its adsorption characteristics. It breaks the micelle effect of SDS and the "solid sealing" effect of hydrates, increases the formation rate of hydrate in heterogeneous heterogeneous environment, and promotes hydrate formation. Therefore, the synergistic system of porous media and surfactant can significantly improve the hydrate generation rate and gas storage effect, and provide a theoretical basis and research direction for the rapid hydrate generation technology.

Key words: Methane hydrate, Porous media, Calcium carbonate, Surfactant, Synergy, Induction time

摘要： 天然气水合物的储量决定其潜在的商业开发价值。结合海底沉积物成分及海底环境，在2 ℃和6.08 MPa的条件下研究碳酸钙作为多孔介质与十二烷基硫酸钠（SDS）的协同体系对甲烷水合物生成情况的影响，并对其进行机理分析。结果表明，二者协同体系的储气效果和储气速率均优于纯SDS溶液。碳酸钙的粒径变化会改变水合物的生成量和储气效果，其中1 mm碳酸钙的储气效果最优。协同体系极大地缩短了水合物的诱导期，加快了水合物成核速率。协同体系的促进效果体现在SDS的促进效果和碳酸钙表面特性和粒径改变的促进效果及吸附特性，打破了SDS的胶束作用和水合物的“固封”效应，增大了水合物在异相非均质环境中的生成速率，进而促进水合物的生成。因此，多孔介质与表面活性剂的协同体系可以明显地改善水合物生成速率和储气效果，为水合物快速生成技术提供了理论依据和研究方向。

关键词: 甲烷水合物, 多孔介质, 碳酸钙, 表面活性剂, 协同作用, 诱导时间