小管径天然气管道封堵动火作业新技术

氮气置换动火技术因操作规程标准和指标控制严格、安全等级极高,常用于气田管道动火作业,但投运后的天然气管道中除含大量甲烷外还含少量凝析油和游离水,导致氮气置换动火作业存在困难,管道内无法置换干净的凝析油因挥发导致置换作业周期延长、成本增加。通过将研制成功的天然气管道新型封堵剂（固水乳化剂）及小管径冷冻封堵工艺和设备,与气田现用置换动火技术结合,有效地缩短小管径天然气管道置换动火作业周期,降低作业成本,确保氮气置换动火作业更经济、更安全、更实用。

New Hot Work Technique for Small Diameter Gas Pipeline Blockage

Nitrogen replacement technique is widely used in the hot work of gas pipelines because of its standard operating procedures,strict control specifications and high safety level.However,after putting a gas pipeline into operation,there is a small amount of condensate oil and free water in addition to large amounts of methane in the pipeline,which could lead to difficulty for the hot work with nitrogen replacement.Condensate oil in the pipeline can’t be replaced completely and residual condensate oil will volatilize leading to replacement operation period extended and cost increased.By combining the use of the developed new blockage agent(water fixation emulsifier) and the process and equipment for freeze coagulation blockage of small diameter pipeline with the available replacement technique for hot work,the operational period and cost of hot work for small diameter pipeline will decreased effectively and the hot work will be more economical,safer and more practical.