高含CO2天然气运输管道缓蚀剂的筛选

大多数天然气藏CO2含量为10%~98%,CO2在不同的温度、压力条件下腐蚀极其严重。文章主要针对高含CO2天然气运输管道腐蚀的问题,开展缓蚀剂的筛选,重点开展CO2腐蚀规律研究与实验,评价环境温度、CO2分压、流动速度对腐蚀规律的影响,明确缓蚀剂的影响因素,结合管材的材质,优选评价不同类型的缓蚀剂,缓蚀效率分别为90.53%和92.64%,在管道凝液介质的气相及液相中都有较高的缓蚀效率。通过设计现场加药工艺及制度,监测评价缓蚀剂缓释效果和腐蚀情况,可防止管道运输过程中CO2腐蚀的侵害,长输管线内腐蚀控制良好。

Selection of Corrosion Inhibitors for Natural Gas Transportation Pipelines with High Content of CO2

The content of CO2 in different gas reservoirs ranges from 10% to 98%,the CO2 corrosion is extremely severe under different temperature and pressure conditions.This paper focused on the corrosion problem of the high CO2 content natural gas transportation pipelines,the selection of corrosion inhibitors was carried out,the research and experiment of CO2 corrosion law,the influence of environmental temperature evaluation,CO2 partial pressure and flow rate on corrosion law were investigated.In combination with the material of pipes,the influencing factors of corrosion inhibitors were considered for the selection and evaluation of different corrosion inhibitors.Under high temperature and high pressure experiments,high corrosion inhibition efficiency was obtained both in gas phase and liquid phase of pipeline condensate medium,the corrosion inhibition efficiency is 90.53% and 92.64% respectively.By designing the on-site dosing process and system,detection and evaluation of the slow release effect and corrosion of corrosion inhibitor,CO2 corrosion during pipeline transportation can be prevented,resulting in the well control of the long-distance pipelines internal corrosion.