长输天然气管道冬季冻堵防治实例

Controlling freezing/ice blockage cases of winter for long-distance natural gas pipeline

中国石化榆济输气管道在试运行过程中,因发生水合物冻堵事故,西源祠阀室、石门阀室、杨家峪阀室压力变化异常,通过分析上下游管道的运行参数和统计管道工程遗留的裸管段,初步确定两处裸管段为线路冻堵点:1#冻堵点位于西源祠阀室和石门村阀室之间的爬坡段,2#冻堵点位于石门村阀室和杨家峪阀室之间的U形弯管段。根据现场实际,在采取应急处置措施的基础上,将加注醇类抑制剂、管道天然气放空、全线降压运行和加装电伴热4种方法结合使用,很快缓解了冻堵现象,确保了管输安全。

Freezing/ice blockage accident induced by hydrate happened during commissioning of SINOPEC YuJi Gas Pipeline,which led to the abnormal pressure changes in Xiyuanci Valve Chamber,Shimencun Valve Chamber and Yangjiayu Valve Chamber.Statistical analysis was made on running parameters from upstream and downstream pipeline and the bare pipe sections remained during the construction of the pipeline.Results showed that ice blockage of the pipeline was found at two bare pipe sections,in which,the 1st ice blockage was located at the upward pipeline between Xiyuanci Valve Chamber and Shimencun Valve Chamber,and 2nd ice blockage was located at the U-shape bending pipe section between Shimencun Valve Chamber and Yangjiayu Valve Chamber.Besides emergency disposal,effective measures,refilling alcohols inhibitors,venting,running under decreased pressure and heat tracing,were successfully taken to treat with the ice blockage accident.