初始压力对多孔介质中气体水合物生成的影响

On the Influence of Initial Pressure on Natural Gas Hydrate Formation in a Porous Medium

利用自制的一维天然气水合物生成与开采模拟实验系统,实验研究多孔介质中天然气水合物生成时不同初始压力对生成量、生成时间的影响。分别用相同气水比注入、相同注气量不同注水量、相同注水量不同注气量三种方式来控制初始压力。结果表明:在砂粒粒径300μm^500μm,盐水质量浓度2%,系统温度为2℃、初始压力为5MPa^9MPa的条件下进行水合物的等容生成实验时,初始压力越大,生成的水合物量越多,水合物开始生成的时间越早;但初始压力越大,实验系统中水合物生成最终稳定所需的时间越长。本实验系统采用的三种不同的控制初始压力的方式都可以得到上述结果。由此,可以为今后室内进行天然气水合物的生成实验提供科学指导。

The influence of different initial pressure on the amount and duration time of natural gas hydrate（NGH） formation in a porous medium was studied by using a home-made one- dimensional NGH formation and exploitation simulation experimental system. Three means were adopted to control the initial pressure： same gas/water ratio injection, same gas amount with different water amount injection, and the same water amount with different gas amount injection. The isometric formation took place under following conditions： grain size was 300-500μm, mass concentration of salt water was 2%, system temperature was 2℃, and initial pressure was 5-9MPa. Results show that NGH forms earlier and more amount of NGH is obtained under higher initial pressure, but it needs more time for completion of formation process. Same results were obtained by above-mentioned three means used to control the initial pressure. Further indoor experiments of NGH formation can be conducted under scientific guidelines based on this experiment.