Corrosion failure cause analysis and evaluation of corrosion inhibitors of Ma Huining oil pipeline

•The work studies corrosion failure analysis of × 52 pipeline in Ma Huining.•The structure of corrosion products is analyzed in the water injection pipe.•The corrosion of × 52 pipeline steel is mainly induced by oxygen corrosion and SRB.•The inhibitor with oleic acid imidazoline amide and sodium sulfite was optimal.

The corrosion failure cause analysis of Ma Huining × 52 oil pipeline has been investigated in the present study. The morphology and composition of the corrosion products are characterized by scanning electron microscopy, energy-dispersive spectroscopy and water quality analysis. The static and dynamic weight loss experiment is conducted to estimate corrosion rate of × 52 pipeline steel with different inhibitors. With the addition of electrochemical impedance test and polarization curve method, the inhibitors aimed at corrosion of Ma Huining oil pipeline have been evaluated. Results show that corrosion of × 52 pipeline steel is mainly induced by oxygen corrosion and SRB. Non-metallic inclusions are MnS and Al2O3. The inhibitor made up of oleic acid imidazoline amide and sodium sulfite at 80 ppm was optimal for corrosion of Ma Huining oil pipeline.