A probabilistic model for the prediction of flow induced localized corrosion (FILC) has been developed which correlates the hydrodynamic forces exerted onto corrosion product scales with the fracture stress of the scales. The model is based on the hypothesis that FILC is initiated by near-wall turbulence elements above critical flow intensities which are expressed in terms of critical wall shear stresses. The boundary conditions for turbulence induced growth of a microcrack in the scale are
verified with measured fracture mechanics data of iron carbonate scales from CO2 corrosion of low alloy steel. The drag reducing properties of corrosion inhibitors are quantitatively estimated for CO2 and H2S corrosion of carbon steel, allowing an optimization of downhole and pipeline flow velocities with the optimum inhibitor concentration.
Keywords: steel, carbon dioxide, hydrogen sulfide, corrosion, inhibitors, flow, wall shear stress, fracture mechanics, corrosion product scale, model