人造海水中不同的多孔介质内甲烷水合物生成特性研究

结合海底水合物沉积成藏特征,发现水合物易在海底沉积物中生成,且还有类似表面活性剂的催化酶存在。结合以上因素,实验将人造海水和十二烷基硫酸钠(SDS)溶液进行混合,研究了碳酸钙和二氧化硅作为多孔介质时甲烷水合物的生成情况。研究表明:(1)多孔介质体系较无多孔介质体系实验剩余压力更低,水合物的储气密度和储气速率更大,其中1 mm碳酸钙的促进效果最优;(2)多孔介质表面特性和粒径变化均会改变水合物的储气效果,同种粒径下,碳酸钙促进效果优于二氧化硅;(3)人造海水中的低浓度盐类通过离子交换和破坏SDS胶束团的作用,对水合物储气效果的促进优于纯SDS溶液;(4)三者的协同体系可以有效地缩短水合物的诱导期,为探究海底水合物成因和水合物快速生成技术的应用提供了参考。

Study on the formation characteristics of methane hydrate in different porous media in artificial seawater

For the characteristics of submarine hydrate deposition and accumulation, it is found that hydrates are easily formed in submarine sediments, and there are also catalytic enzymes similar to surfactants. For above factors, artificial seawater and sodium dodecyl sulfate (SDS) solution is mixed in the experiment and the formation of methane hydrate by calcium carbonate and silica used as porous media is studied. The research shows that the residual pressure of the porous media system is lower than that of the system without porous media, and the gas storage density and gas storage rate of the hydrate are greater. Among them, the promotion effect of 1 mm calcium carbonate is the best. Changes in the surface characteristics and particle size of the porous medium will change the gas storage effect of the hydrate. At the same particle size, the calcium carbonate promotion effect is better than that of silica. The low-concentration salts in the artificial seawater can promote the gas storage effect of hydrate through ion exchange and destroy the SDS micelle, which is better than pure SDS solution. The synergistic system of the three can effectively shorten the induction period of hydrates, which provides a reference for exploring the causes of seabed hydrates and the application of rapid hydrate generation technology.