模拟渗漏系统气体迁移与水合物形成实验

水合物生成是典型的界面传递输运现象,而气体迁移性质是这种传递过程的决定性因素。在鼓泡透明玻璃反应釜里模拟渗漏系统气体穿越多孔隙砂层形成水合物的过程实验,分析了气体迁移对气体水合物形成时气液界面的传质传热性质影响,表明实验中气体迁移形成水合物的过程是一种相平衡曲线动态移动的过程;在形成水合物的气—液界面存在具有一定厚度的过渡层,只要过渡层内气体达到饱和即可形成水合物;气体在迁移中不断形成水合物并在孔隙中形成过压,导致地层骨架的力学破裂和失稳;必须建立一个新的水合物相图以适应气体迁移形成水合物过程的这种新特性。

Experiment of Simulation Natural Gas Migration Accompanying Hydrate Formation in Seepage System

Hydrate formation is a typical phenomenon of the interface transfer,and the nature of gas migration is the decisive factor for this transfer process.Some experiments have been done by simulating in-situ hydrate formation system by gas migrating in seepage system in a glass bubble cell.The phenomena in experiments indicate that gas migration can change the quality of mass and heat transfer of the interface between gas and liguid when hydrate is forming,and it's a moving process of equilibrium curve.There will exist a "pseudo" buffer layer which has some distance of thickness in the interface between gas and liquid,and for gas migration,as long as gas reaches its saturation in solution in this buffer layer,the hydrate can form.The overburden stress in sediments capillary will gradually breed because of continuously hydrate formation in the course of gas migration,and will cause faults or fractures of the stratum matrix.Therefore,a new hydrate phase diagram must be built up in order to adapt the new characteristic of natural hydrate system brought by gas migration.