基于光电子能谱的高含水输油管道内壁腐蚀减薄试验分析

鄂尔多斯盆地高含水输油管道内壁腐蚀减薄现象普遍，腐蚀穿孔频次逐年上升，管道安全防护管理成为难题。为了识别输油管道内壁腐蚀减薄原因，作者在分析含水率、地层水水型、溶解氧对管道内腐蚀影响的基础上选择特征试验管段，基于X射线光电子能谱技术开展管道内壁厚度变化、金相组织、腐蚀产物特性、边缘腐蚀状态研究。结果表明:高含水输油管道内壁腐蚀减薄类型为Cl+O2+H2O环境下的垢下腐蚀，以溶解氧（O2）腐蚀为主，氯离子（Cl－）腐蚀为辅；内壁腐蚀减薄原因为原油含水率过高、水中氯离子含量过高、水中含有溶解氧和介质流速偏低。

Experimental analysis on internal wall corrosion thinning phenomenon of oil transmission pipelines with high water cut based on photoelectron spectroscopy

The internal wall corrosion thinning phenomenon has been more common and the frequency of corrosion perforation increased year by year for oil transmission pipelines with high water cut in the Ordos Basin, resulting in the high challenge for safety protection and management of pipelines. In order to identify the causes of internal wall corrosion thinning for oil transmission pipelines, the characteristic test pipeline section was selected based on analyzing the influence of water content, formation water types and dissolved oxygen on internal corrosion of pipeline. The research on the variation in thickness, metallographic structure, characteristics of corrosion products and edge corrosion state for internal wall of oil transmission pipelines were conducted based on the X-ray photoelectron spectroscopy technology. The results showed that the internal wall corrosion thinning type of oil transmission pipelines with high water cut is the under-deposit corrosion under the Cl+O2+H2O environment, which is mainly dissolved oxygen (O2) corrosion, complementing with chloride ion (Cl－) corrosion. The causes of internal wall corrosion thinning include too high water content in crude oil, too high chloride ion content in water, dissolved oxygen in water and lower flow velocity of medium in oil transmission pipelines.