横琴-澳门输气管道三甘醇/氮气深度干燥

TEG/nitrogen deep drying for Hengqin-Macao Gas Pipeline

横琴-澳门输气管道工程在首次置换投产过程中,采用深度泡沫球清管、空压机吹扫48h及氮气置换流程,没有达到干燥要求。基于对流动气体蒸发法、抽真空干燥法、干燥剂干燥法的分析比较,特别是干燥剂滞留在管道内能长时间发挥抑制水合物形成的作用,第二次干燥推荐采用三甘醇+液氮气化吹扫的干燥方案。根据具体的干燥要求和管道的实际情况,计算了除水干燥水量、三甘醇用量以及干燥时间,给出了干燥作业步骤与密封稳定验收流程,分析了常见故障原因,并提出了处理措施。

In the first replacement and commissioning process of Hengqin-Macao Gas Pipeline,the method in foam pig's pigging,48-hour purging with air compressor and nitrogen replacement was adopted,but failed to meet the drying requirements.Based on the analysis and comparison of flowing gas evaporation method,vacuum drying method,and desiccant drying method,the advantages of the desiccant drying method,especially desiccant retained within the pipe can inhibit hydrate for long time,TEG+liquid nitrogen purge drying scheme was recommended to used in the subsequent drying.According to the specific drying requirements and the actual situation of the pipeline,this paper calculates the dewatering and drying water volume,TEG consumption volume and drying time,provides the drying operation steps and acceptation flow of sealing stability and analyzes the cause for common failures and puts forward treatment measures.