Corrosion Failure Analysis of X52 Gas Pipeline

Localized corrosion occurred on the outer walls of X52 spiral welded pipeline in a certain oil and gas field. The failure reasons for corrosion of the pipeline were studied by testing the physical and chemical properties of the test pipe section, soil environment analysis, sulfate reducing bacteria (SRB) corrosion testing. The results show that the chemical composition and microstructure of X52 spiral welded pipe conformed to the requirements in technical specifications. The soil around the pipe body had a high moisture content and contained a large amount of sulfate and sulfate reducing bacteria. Anaerobic corrosion of sulfate reducing bacteria happened in the peeling area of the anticorrosive layer at the bottom of the pipe, resulting in severe corrosion pits distributing on localized pipe body without direction.