天然气凝析液管道中射流清管器的运动特性

Movement characteristics of bypass pigs in natural gas condensate pipelines

天然气凝析液管道生产中后期常面临管道内积液增加、沿程摩阻增大的问题,定期清管作业对于保障油气管道的安全高效至关重要。在清管过程中,由于传统清管器运行速度与后方驱动气速相同,可能导致其超出控制,从而引发一系列问题。研制了一款新型的射流清管器,并搭建了与之匹配的水平-立管试验系统,以空气、水为介质,开展不同结构参数的射流清管试验,通过LabView数据采集系统对清管过程中的流量、压力、终端液位等进行实时采集。通过改变旁通率、驱动气速、液速等参数探究射流清管器的运动特性,并分析清管器异常运动过程以及射流消除段塞的内在机理。结果表明:采用射流清管器可达到降低清管器运行速度、平缓管道内压力波动、降低清管器前方段塞持液率、控制段塞体积的目的。研究成果可为深入了解射流清管技术机理,推广其工程应用提供参考。(图14,表2,参39)

In the middle and late production stages of natural gas condensate pipelines,the problems of increased liquid accumulation and friction usually occur in the pipelines.Therefore,regular pigging operations are essential to ensure the safety and efficiency of the oil and gas pipelines.However,the traditional pigs often go out of control as a result of their same velocity with the driving gas during the operation,which brings about a series of problems.Thereby,a new type of bypass pig was designed and developed,and a matching experimental system of horizontal-vertical pipelines was built to analyze the movement characteristics of the bypass pigs in different structures.Herein,air and water were used as the flow media,and the data of flow,pressure and terminal liquid level during pigging were collected by the LabView data collection system in real time.By changing the parameters such as the bypass rate,the driving gas velocity,the liquid velocity,etc.,the movement characteristics of the bypass pig were explored,and the abnormal movement process of the pig and the internal mechanism of eliminating pig slug were analyzed.As shown in the results,the movement velocity of pigs can be slowed,the pressure fluctuation in the pipelines can be mitigated and the liquid holdup in the slugs before the pigs can be reduced with the bypass pigs for the purpose of effectively controlling the volume of slugs.The research results could provide references for in-depth understanding of mechanism of bypass pigging technology and promoting its engineering application.(14 Figures,2 Tables,39 References)