魏荆管道停输再启动困难的原因分析

近几年来魏荆管道采用了添加降凝剂的输油工艺，随着输油管道运行条件的变化，原来的输油条件已不能简单移植到新的输油工艺上，为了确定新工艺条件下道道的安全停输时间，在魏荆管道进行了停输再启动的现场试验。

Reason analysis for difficulties of restart after shutdown in Wei Jing pipeline

In recent years, oil transportation process with depressant has been adopted in Wei Jing pipeline. A-long with changing operating conditions over the pipeline, the original oil transporting condition can not be shifted simply to a new transporting process. In order to determine pipeline's safety shutdown time under new process condition, restart after shutdown test is carried out at Wei Jing pipeline site. The article discusses preparing works before restart after shutdown operation, shutdown condition and restart after shutdown process, and analyzes reasons of difficulties found in the period of restart after shutdown process: (1) uneven crude oil inside pipeline and great difference in oil quality; (2) serious pipe wall wax deposition and small equivalent pipe diameter; (3) large pipeline fluctuation forms mechanical admixture and deposition of wax. It also puts forward a number of proposals for future pipeline operation.