A Fundamental Understanding of Erosion-Corrosion of Hydrotransport Pipes in Oil Sands Slurry

Erosion-corrosion (E-C) of X-65 pipe steel was investigated in a simulated oil sand slurry through an impingement jet system. Measurements of weight-loss and potentiodynamic polarization curves combined with optical microscopy observation were performed to determine the synergism of corrosion and erosion in E-C of steel. It was found that passivity of the steel developed in static oil-water emulsion cannot be maintained in the flowing fluid due to the enhanced activity of the steel upon impingement of the emulsion/slurry. The effect of slurry impact angle on E-C of steel is complex, depending on the magnitude and synergism of shear stress and normal stress exerting on the electrode surface. There is a synergism of corrosion and erosion in E-C of steel. The contributions of corrosion and erosion to E-C rate of the steel in oil sand slurry rank approximately 30% and 70%, respectively. Erosion dominates the E-C of X-65 steel in oil sand slurry.