中文摘要：

引言 20世纪30年代，在前苏联的天然气管道中首次发现了天然气水合物。自此之后随着石油工业的快速发展，天然气水合物对石油工业造成的影响也越来越大，尤其是从20世纪70年代开始，一些环境恶劣的油田（比如阿拉斯加北坡、西伯利亚、北海等）以及一些深海油田（比如墨西哥湾、西非、巴西等）逐渐投入生产，传统的水合物防治方法的缺陷更加明显，而且一些技术上的问题也限制了传统方法的使用。

英文摘要：

The flow assurance problem of pipelines in offshore production is becoming more and more serious because oil fields in more and more unusual environments have been brought in production.HCFC-141b and THF were selected as the substitutes to study the flow behavior and mechanism of hydrate blockage in pipelines on the newly built flow loop,which was a two pass loop consisting of a 42 mm diameter stainless pipe,30 m long.Slurry-like hydrates and slush-like hydrates were observed with the formation of hydrates in pipeline.There are critical hydrate volume concentrations of 37.5% for HCFC-141b hydrate slurry and 50.6% for THF hydrate slurry respectively.The pipeline would be free of hydrate blockage when the hydrate volume concentration was lower than the critical volume concentration; while otherwise the pipeline would be easily blocked.A safe region,which is defined according the critical hydrate volume concentrations,is firstly proposed for hydrate slurry,and it can be used to judge if the pipeline can be run safely or not.