【摘要】 多孔介质中甲烷水合物的形成及分解实验研究,对于了解多年冻土中天然气水合物的赋存有重要意义.通过X射线扫描系统对粗砂土中甲烷水合物的形成及分解过程中反应釜内水分的空间变化进行分析,结果表明:粗砂土中甲烷水合物的形成和分解过程中,CT数在反应釜内有明显的空间变化特征,且这个空间变化特征与甲烷水合物在粗砂土中形成、分解过程中水分的迁移是密切相关的.通过对不同阶段CT扫描所获得图像CT值的空间变化特征进行分析,可以看出:在甲烷水合物的生成过程中,反应釜内下半部分的水分会向上半部分迁移,以弥补上半部分水分的不足;在甲烷水合物分解过程中,分解所释放出来的水分会由反应釜上半部分向下半部分回迁,最终达到自然分布.更多还原

【Abstract】 An experimental research on formation and dissociation of methane hydrate in porous media is very important for understanding the occurrence of natural gas hydrate in permafrost regions.The moisture migration during methane hydrate formation and dissociation processes was researched by CT in this work.It is found that the changes of CT value were evident and these changes were relative to the moisture migration.After analysis of different CT images,the spatial characteristics of CT value change during methane hydrate formation and dissociation are obtained.During formation process,the moisture migration is from the bottom of the reactor to the top.And during the dissociation process,the moisture migration is from the top to the bottom till its natural distribution.更多还原