摘要
为了解决高温稠油输送管道的腐蚀问题,通过典型稠油输送管道的外腐蚀分析,结合室内试验和现场测试,明确埋地保温稠油输送管道的腐蚀原因,进而提出相应的防治措施。结果表明:检测管段在补口位置未安装防水帽,搭接片处出现明显渗水痕迹,土壤水介质沿管道渗入导致整个渗水管段中下部发生较为严重的腐蚀。腐蚀最严重部位位于管道周向135°~180°,距补口渗水处10 cm,管道最小剩余壁厚为4.54 mm,最大点蚀深度为2.51 mm,底部力学性能显著降低;阴极保护电流屏蔽、最小阴极保护电位过高,以及管道服役时间过长、管输温度高是导致该稠油输送管道发生外腐蚀的主要原因。针对该高温稠油输送管道的腐蚀原因,从阴极保护实施方式和准则、防腐层材料选择、缓蚀剂防腐以及管输技术等方面,提出了相应防治措施,可以有效地解决相关问题,为管道的设计、建设、运营提供技术支撑。
Combined with laboratory test and field test,the reasons of corrosion for buried insulation heavy oil pipelines are clarified through the external corrosion analysis of typical heavy oil pipeline,and the corresponding prevention measures are put forward.The results show that the inspection pipe segment does not have waterproof cap in the joint coating,water seepage traces are observed at the lap joint strap.Infiltrated soil water medium along the pipe lead to serious corrosion in the middle and lower parts of the whole seepage pipe segment.The most severely corroded part is located in the circumference of the pipeline at 135°~180°,10 cm away from the seepage position of joint coating.The minimum residual wall thickness of the pipeline is 4.54 mm,and the maximum pitting depth is 2.51 mm.It significantly reduced the mechanical properties of the bottom.Cathodic protection current shielding,extreme high minimum cathodic protection potential,excessively long service time,exceeding over high pipeline transportation temperature are the main reasons which result to the external corrosion of the heavy oil pipeline.In view of the corrosion causes for the high temperature heavy oil pipeline,the corresponding preventive measures are put forward from the aspects of the implementation mode and criterion of cathodic protection,selection of corrosion protection coating material,corrosion inhibitor technology and pipeline transportation technology,etc.It can effectively solve related problems and provide technical support for pipeline design,construction and operation.
作者
李洪福
曾海伟
胡宁
李媛媛
程猛猛
赵凯华
马晓凤
王晨
LI Hongfu;ZENG Haiwei;HU Ning;LI Yuanyuan;CHENG Mengmeng;ZHAO Kaihua;MA Xiaofeng;WANG Chen(OiL&Gas Storage and Transportation Company,Xinjiang Oilfield Co.,Ltd.,CNPC;Construction Project Labor Safety and Health Pre-assessment Co.,Ltd.,CNPC;School of Materials Science and Engineering,Xi’an Shiyou University)
出处
《油气田地面工程》
2021年第2期82-91,共10页
Oil-Gas Field Surface Engineering
基金
国家自然科学基金项目,51902254
陕西省自然科学基金青年项目,2018JQ5108。
关键词
高温稠油输送管道
外腐蚀原因
阴极保护
防治措施
high temperature heavy oil pipeline
external corrosion cause
cathodic protection
prevention and control measures
