多孔介质中甲烷水合物的分解特性

利用定容降压方法测定了在不同多孔介质中甲烷水合物的分解实验数据, 所使用的多孔介质平均孔径分别为9.03, 12.95, 17.96和33.20 nm, 其中孔径为12.95 nm的多孔介质采用了3个粒径范围, 分别为0.105～0.150, 0.150～0.200和0.300～0.450 mm; 其它孔径的多孔介质的粒径范围为0.105～0.150 mm. 在封闭的条件下测定了不同温度与不同初始生成压力下甲烷水合物的分解实验数据(实验温度范围为269.15～278.15 K, 初始生成压力范围为4.1～11.0 MPa), 结果表明, 水合物的分解速度随着初始生成压力的增加和水浴温度的降低而升高, 也随孔径的增加而升高, 但随多孔介质粒径的增大而降低. 在孔径较大和分解温度较低时, 多孔介质中水合物分解引起的温度降低会使水结冰, 从而减缓水合物的分解速度.

Dissociation Behavior of Methane Hydrate in Porous Media

The dissociation behavior of methane hydrate in the porous media were studied when the temperature was above the quadruple phase[Hydrate(H)-Water(L_W)-Ice(Ⅰ)-Vapor(Ⅴ)] point temperature. The silica gels were applied as the porous media for the experiments, in which the diameter ranges of the silica gel particles were 0.105-0.150, 0.150-0.200 and 0.300-0.450 mm, and the mean pore diameters, 9.03, 12.95, 17.96 and 33.20 nm, respectively. The dissociation experiments were carried out by depressurization in the temperature range of 269.15-278.15 K and the initial formation pressure range of 4.1-11.0 MPa. The experiments indicated that the dissociation rate of methane increases with the increase of the initial formation pressure, the decrease of the bath temperature, the decrease of the particle range and the increase of the mean pore diameter. For relative big the particle diameter, the water in some pores becomes ice in the disso-ciation process, which makes the dissociation process relatively slow.