涩宁兰输气管道水合物事故及其预防

Hydrate accident and prevention in Sebei-Xining-Lanzhou Gas Pipeline

涩宁兰输气管道沿线经过我国西北高原寒冷地区,因输送气质含水量较大、管道投运过程干燥不彻底,导致管道中存留液态水,在高压、低温条件下极易发生水合物冻堵。针对2010年冬季涩宁兰输气管道兰州末站发生的水合物堵塞事故,对管道中天然气气质的水露点和运行参数进行分析。将天然气的水露点值换算成含水量值,并将分析得到的含水量值和工艺运行参数范围与水合物生成条件参数进行对比,根据对比结果控制管道的运行参数,以防止水合物的生成。介绍了通过添加抑制剂防止水合物生成的方法及其添加量的计算方法。涩宁兰输气管道水合物事故分析与预防技术实践表明:与添加抑制剂方法相比,采用检测气质参数和监测管道工艺运行参数防止输气管道系统中生成水合物的方法,更能满足生产要求,且经济性与安全性更高。

Sebei-Xining-Lanzhou Pipeline passes through cold regions in the northwest plateaus of China.Due to gas with higher moisture and pipeline not being complete dried in the operation process,liquid water occurs in the pipeline,so that pipelines are vulnerable to frozen hydrate blockages.For the hydrate blockage accident which occurred at the Terminal Station in Lanzhou of Sebei-Xining-Lanzhou Gas Pipeline in winter of 2010,the dew point of gas and operating parameters of the pipeline were analyzed.The dew point value of natural gas was converted into water content value,and the water content value and process operating parameter scope obtained from the analysis were used to compare with hydrate formation condition parameters.Based on comparative results,operating parameters of the pipeline were controlled to prevent the formation of hydrate.The method to prevent hydrate formation by inhibitor injection and calculation method of the concentration were introduced.Practices in hydrate control technology in the pipeline hydrate accident indicated that compared with the inhibitor injection method,the method to detect gas parameters and monitor pipeline process operating parameters for preventing hydrate formation in the gas pipeline system can meet the requirements of operation and is more economic and safe.