天然气水合物形成及聚集形态实验

Experimental Investigation of Formation and Aggregation Morphologies of Natural Gas Hydrate Formation

采用自行设计的高压反应釜进行了油水及含粉砂体系天然气水合物的生成实验,分析了含水率、防聚剂司盘80(Span80)浓度及粉砂对水合物生成形态的影响。结果表明:水合物生成位置包含液滴表面(高含水率除外)、气-液-固界面和气-固界面;Span80浓度上升,乳状液越稳定,水合物生成位置由气-液-固界面转移至液滴表面;同时,水合物形态先由块状变化至分形聚集体,进而变化为颗粒状,形成稳定的水合物浆。含粉砂体系水合物颗粒含有包裹砂粒和不包裹砂粒的两种形态,附壁水合物层呈分层结构;含砂流动体系中泥沙颗粒以含砂水合物颗粒碰撞粘附和卷携砂粒的形式进入水合物层中。

With the help of a sapphire high pressure reactor,experiments of water cut,the concentration of antiagglomerant（ Span80） and muddy silt on the place of NGH formation,and the morphologies of NGH formation were carried out and analyzed. The result shows the position of hydrate formation contains droplet surface,gas-liquid-solid interface,and gas-solid interface（ except the condition of high water cut）. With the increase of the concentration of Span80,the emulsion becomes more stable and the position of hydrate formation is transferred from gas-liquid-solid interface to droplet surface,meanwhile,hydrate form is changed firstly from bulk to fractal aggregation and then particle,resulting in the formation of stable hydrate slurry. Additionally,it was observed that hydrate particles were formed with and without sand,and that the wall-attached hydrate layer presented a sandwich structure. The rolling and colliding implantations of hydrate particles were also observed experimentally. Sand aggregation was caused by hydrate particle implantation and the carrying sand effect. The analysis of hydrate formation and aggregation morphology can provide technical guidance for the study of particle aggregation and jam in the pipeline.