缓蚀剂在天然气集输管道内的分布规律及对管道腐蚀的影响

Distribution of Inhibitor on the Internal Surface of the Natural Gas Gathering Pipeline and Its Effect on the Corrosion Behavior

采用数值模拟计算的方法分别对批处理缓蚀剂和连续处理缓蚀剂在某天然气集输管道内的分布规律进行研究,根据缓蚀剂在管道顶部和底部的分布规律,通过腐蚀模拟试验分别研究了管道的底部和顶部腐蚀行为。结果表明:在天然气流作用下,批处理缓蚀剂膜在管道内部分布不均,缓蚀剂膜在管道顶部的厚度低于管道底部,弯头内侧的批处理缓蚀剂膜明显减薄;连续处理缓蚀剂在重力作用下主要沉降在管道底部,仅弯头的顶部受少量缓蚀剂的保护。在批处理缓蚀剂和某一浓度的连续处理缓蚀剂作用下,管道底部的腐蚀基本上得到了控制,但管道顶部发生了明显的局部腐蚀。

Distribution of batch inhibitor and continuous inhibitor on the internal surface of natural gas gathering pipeline was investigated by numerical simulation method, and then its effect on the top and bottom of line corrosion was studied in the laboratory. The results in- dicated that the thickness of batch inhibitor on the top of the line was thinner than that on the bottom of line due to the flow, and it was much thinner at inside of the elbow than that on the top and bottom of the line. Most of the continuous inhibitor was found on the bottom of line due to the effect of gravity of inhibitor. Only the top of the elbow was protected by a small part of continuous inhibitor. Bottom of line corrosion was inhibited at the combination of batch inhibitor and a certain concentration of continuous inhibitor, but localized corrosion was observed on the top of the line.