多孔介质水合物中未水合水的核磁共振实验研究

NMR study of unhydrated water in hydrate of porous media

利用低场核磁共振技术开展多孔介质水合物中未水合水研究,提出一种定量分析含水合物的多孔介质未水合水含量的实验方法。研究结果表明:颗粒粒径越小,未水合水含量较高;当颗粒粒径相同时,初始含水量越高未水合水含量也越高;初始压力越低,未水合水含量越高;未水合水含量较高时多分布于较大孔隙和大孔隙中,未水合水含量较低时多分布于小孔隙和较大孔隙中。在水合物形成过程中,颗粒粒径、初始含水量及初始压力均对水分的迁移有一定影响,最终影响未水合水的含量及孔隙分布变化。

Low-field nuclear magnetic resonance(NMR)technology was used to study unhydrated water in the hydrate of porous media.On that basis,a novel quantitative experimental approach to identify the unhydrated water content in the hydrate of the porous media was proposed.The results show that the smaller the particle size is,the higher the content of unhydrated water is.When the particle sizes are the same,the higher the initial water content is,the higher the content of unhydrated water will be.Meanwhile,a lower initial pressure is associated with a higher content of unhydrated water.When the content of unhydrated water is high,it is mainly distributed in the relatively large and large pores.However,when the content of unhydrated water is low,it is generally found in the relatively large and small pores.The particle size,initial water content,and initial pressure affect water migration during the formation of hydrate,which can ultimately affect the content and distribution of the unhydrated water in the pores.