The efficiency and safety of natural gas hydrate exploitation is significantly affected by the occurrence and distribution of hydrate and the seepage behaviors of gas and water in hydrate bearing sediments. We present the results from xenon hydrate formation and dissociation experiments with different salinities using quartz etching microfluidic chips. Direct visualization of hydrate growth morphology is obtained with the help of industrial grade charge coupled device (CCD) camera coupled with a microscope module. The results show that the hydrate growth process in microfluidic chip can be divided into four stages, which are the hydrate inducing stage, the primary hydrate nucleation stage, the rapid hydrate nucleation stage and the hydrate nucleation maturation stage, respectively. Different hydrate morphologies (dendritic, intestine-like) and aggregation patterns (grain-coating, grain-cementing) are observed during the different stage of hydrate formation. The average value of all 219 contact angles of water phase on gas-hydrate interface is 44.03°, which indicates the hydrate surface is hydrophilic. And the hydrophilicity of the hydrate surface is impaired by the increase of brine salinity, owing to the loss of attraction between the molecules caused by the salt-removing effect during the hydrate formation process. The effective water permeability in hydrate bearing microfluidic chip decreases with the decrease of the pore size and is further affected by the heterogeneity. The permeability reduction caused by the hydrate formation is more pronounced in the microfluidic chips with larger initial pores. The hydrate formation kinetics is significantly inhibited by the coupling effect of the tortuosity, the pore size and the salinity and resulted in drastic reduction in hydrate saturation.

天然气水合物开采的效率和安全性受到水合物的发生和分布以及含水合物沉积物中气体和水的渗流行为的显着影响。我们介绍了使用石英蚀刻微流控芯片在不同盐度下氙水合物的形成和解离实验的结果。借助配有显微镜模块的工业级电荷耦合器件（CCD）相机，可以直接观察水合物的生长形态。结果表明，微流控芯片中水合物的生长过程可分为四个阶段，即水合物诱导阶段，初级水合物成核阶段，快速水合物成核阶段和水合物成核成熟阶段。不同的水合物形态（树枝状，在水合物形成的不同阶段观察到肠样和聚集模式（颗粒状包衣，颗粒状固结）。气水合物界面上水相的所有219个接触角的平均值为44.03°，表明水合物表面是亲水性的。由于在水合物形成过程中由于脱盐作用而导致分子之间的吸引力损失，盐水盐度的增加削弱了水合物表面的亲水性。含水合物的微流体芯片中的有效透水度随着孔径的减小而降低，并进一步受非均质性的影响。由水合物形成引起的渗透率降低在具有较大初始孔的微流控芯片中更为明显。