Research On The Inspection And Mitigation Practices Of Stray Current In Pipelines

In this paper, the criterions and papers about stray current interference were analyzed, and the research topics about stray current were categorized and concluded. The inspection, evaluation and mitigation technology of stray current were compared. The technology integration has completed by adopting flow chart.The synchronous monitoring method was designed in order to locate the stray current interference source. The method was tried on the interference section of Qinjing pipeline and Gangzao pipeline and the interference distribution law and interference source was determined. Meanwhile this inspection method was applied to other pipeline in Petrochina Pipeline Company, such as Tieda pipeline, JiLu pipeline.Through the effectiveness evaluation of stray current drainage facilities, including sacrificial anode, polarity drainage, limiting potential drainage, DC-solid decoupler, and the evaluation report was completed. By the evauation, the cathodic protection trouble of Qinjing Pipeline was removed.Through the comprehensive evaluation of drainage facilities, the solid DC decoupler technology was elected to drain the stray current in Gangzao and Qinjing Pipeline. Three drainage facilities were installed in Qinjing pipeline, and another three drainage facilities were installed in Gangzao Pipeline in two batches, and the grounding technology of solid DC decoupler was optimized in the second batch, which effectively mitigated the AC stray current interference. The interference value was controlled below the threshold by the criterion and the cathodic protection was not influenced.