The Pipeline Outside Corrosion Detection Technology Research And Evaluation Of Daqing Refining & Chemical Gas Pipeline

Pipe transportation has the advantages of high efficiency, low cost and reliability, and is playing an increasingly important role in oil and gas transportation. But due to operating year’s growth, environmental change corrosion and other reasons, some phenomenon such as pipeline damage, oil and gas leak is prone to occurred. This caused huge economic losses and brought great potential threats to our people’s life and property and also the environment. In order to ensure the safety of the pipeline operation, the corrosion status of the pipeline is studied, the safety status of the pipeline is evaluated, and the reasonable rectification scheme is given, which has great significance for the safe operation of the pipelines.This paper research contents included the following aspects:First of all, the chemical corrosion and electrochemical corrosion mechanism of metal pipes was studied, the comprehensive evaluation of soil corrosion was carried out. The test results show that the soil erosion is strong along the line.Second, by processing and analyzing DCVG/CIPS field test data of Daqing refining & chemical gas pipeline, the result show that the transmission pipeline corrosion is serious, and the catholic protection is poor, it need rectification.Finally, set up the pipeline defects Von Mises stress finite element analysis and calculation model, and studied the uniform corrosion defect length, width and depth, local corrosion cases the influence law of pore size and depth of the Von Mises stress. On this basis, the Von Mises stress of the pipeline defects is analyzed. The results showed that the daqing refining raw material gas pipeline metal loss defects(ML), a total of 3052, when need immediate repair of 97 defects in 406 corrosion defects of Von Mises stress exceeds the yield strength.