Analysis of Penetration Failure of L360N Linepipe for Shale Gas Gathering Pipeline

The penetration failure of the Φ89.0 mm×5.0 mm L360N linepipe for the gathering pipeline is analyzed by means of macro-morphological analysis,physical and chemical property testing,scanning electron microscope,energy spectrum analysis,and X-ray diffraction etc.The results show that the main reason for the penetration of the linepipe is that the transported fluid contains corrosive media such as CO₂,sulfate-reducing bacteria,and Cl^-,etc.,which first causes local pitting corrosion on the inner surface of the pipe,and then the said penetration occurs with the effect of repeated erosion by the sand-carrying flowback fluid.Accordingly it is recommended to conduct an overall inspection to the inner surface of the pipeline,and to carry out an investigation and research on the corrosion-prevention technology and measures for the linepipe.