延长联络管线埋地金属管道的管外阴极保护研究

发布时间：2018-11-12 20:25

【摘要】：由于传输距离长、环境复杂多变、故障难于检测等特点,埋地金属油气长输管道腐蚀问题对管道的长期安全稳定运行具有重要的影响,一旦发生腐蚀泄漏必然引发环境的严重破坏。阴极保护作为一种有效控制腐蚀的重要手段,在油田生产中得到了日益广泛的应用,因而在特定条件下对其作用机理和应用的研究就显得十分必要。为了提高埋地金属管道阴极保护的保护效果,延长管道的使用寿命,在对土壤的腐蚀特性和腐蚀机理进行研究的基础上对延长油田联络管线破损点位置及防腐层状况进行了调研和检测,并对检测结果进行了系统分析,得出了相应的处理方法。首先,对延长油田联络线所处土壤的电阻率、酸碱度、土壤腐蚀电流密度等特性进行研究,获取了第一手的当地土壤腐蚀特性资料,为特定条件下腐蚀特性研究提供有力的依据。其次,采用交变电流梯度法对延长油田联络线管道破损和防腐层破坏情况进行了检测,获取了详细的管道现场情况的资料,为把握现场腐蚀情况奠定基础。再次,采用PCM检测仪对管道防腐层进行检测,并用CDFFW软件对管道中的电流进行分析,得出管道外防腐层的绝缘电阻率。最后采用管道电流检测的方法对管道运行过程中的杂散电流进行检测,并对杂散电流的产生原理、影响因素、电流来源和排流方案进行分析。通过对联络线河流穿越段以及地势起伏较大的管段阴极保护系统检测结果进行检测和分析,提出增设阳极保护等辅助保护等解决方案,为管线的运行提供有益的借鉴和支持。
[Abstract]:Due to the characteristics of long transmission distance, complex environment and difficult fault detection, the corrosion problem of buried metal oil and gas pipeline has an important effect on the long term safe and stable operation of pipeline. Once corrosion leakage occurs, it will lead to serious damage to the environment. Cathodic protection, as an important means to control corrosion effectively, has been widely used in oilfield production, so it is necessary to study the mechanism and application of cathodic protection in specific conditions. In order to improve the cathodic protection effect of buried metal pipeline and prolong the service life of pipeline, Based on the study of soil corrosion characteristics and corrosion mechanism, the damage location and anticorrosive coating condition of Yanchang oil field liaison pipeline were investigated and detected, and the results were systematically analyzed, and the corresponding treatment methods were obtained. First of all, the characteristics of resistivity, pH and corrosion current density of the soil in Yanchang Oilfield are studied, and the local soil corrosion characteristics are obtained. It provides a powerful basis for the study of corrosion characteristics under specific conditions. Secondly, alternating current gradient method is used to detect the damage of pipeline and anticorrosion layer in Yanchang Oilfield, and the detailed data of pipeline site are obtained, which lays a foundation for grasping the corrosion situation in the field. Thirdly, the pipeline anticorrosive coating is tested by PCM detector, and the current in the pipeline is analyzed by CDFFW software, and the insulation resistivity of the anticorrosive coating is obtained. Finally, the stray current in the pipeline operation process is detected by the method of pipeline current detection, and the principle of the stray current generation, the influencing factors, the current source and the drainage scheme are analyzed. Through the detection and analysis of the results of cathodic protection system in the river crossing section of tie line and the pipe section with large terrain fluctuation, a solution such as adding anode protection and other auxiliary protection is put forward to provide useful reference and support for the operation of pipeline.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE988.2

【参考文献】