页岩气脱水装置TEG重沸器火管结垢问题分析及解决方案

Analysis and solutions on scaling problem of TEG reboiler fire tube in shale gas dehydration unit

重沸器作为TEG再生系统的关键装置,其内部U型火管结垢会导致局部变形凹陷,严重情况下甚至会破裂,导致整个TEG再生系统停运,天然气脱水系统失效,对生产产生极为严重的影响。针对此项问题,通过对结垢物、TEG溶液取样进行组分分析,将化验结果和现场实际页岩气开采方式、TEG脱水系统运行工艺相结合进行分析。结果表明:①页岩气生产采出的高矿化度返排液进入TEG脱水系统是重沸器火管结垢的主要成因;②气井采用泡排工艺后会加大高矿化度返排液进入TEG脱水系统的量,应及时采取措施。结论认为:通过对工艺设备和生产模式等方面进行优化改进,可以很好地预防重沸器U型火管结垢,为页岩气处理净化站解决类似生产问题提供参考,保障天然气TEG脱水系统设备设施的安全平稳生产。

Reboiler is the key device of TEG regeneration system.The scaling of internal U-shaped fire tube will lead to local deformation and depression.In severe cases,the U-shaped fire pipe can even rupture,which will lead to the shut down of whole TEG regeneration system and the failure of natural gas dehydration system,and have a very serious impact on production.In order to solve this problem,the scaling matter and TEG solution were sampled for components analysis,and the test results were combined with the actual shale gas production mode and the operation process of the TEG dehydration system.The results showed that:(1)The main cause of scaling in the reboiler fire tube was that the high salinity backflow produced in shale gas production enters the TEG dehydration system;(2)The amount of the high salinity backflow entering the TEG dehydration system would increase when the bubble drainage process was adopted in the gas well.The conclusion was that the scaling of U-shaped fire tube in reboiler could be prevented by optimizing the process equipment and production mode,which could provide a reference for solving similar production problems in shale gas treatment and purification station,and guarantee the safe and stable production of TEG dehydration system equipment and facilities.