Corrosion and pH prediction in the annulus of flexible pipes under high pressure of CO2

International audience; Annulus of flexible pipelines represents a specific corrosive environment for the high strength carbon steel wires, mainly due to the low V/S ratio between the volume of electrolyte and the exposed steel surface. This environment induces high super-saturation levels of dissolved iron, together with the establishment of pH values far above thermodynamic equilibrium. Nevertheless, it also induces difficulties to predict actual levels of pH in the annulus, since thermodynamic models do not apply. In order to overcome these difficulties, and to obtain trustful pH values for the design of flexible pipelines, lots of efforts were put both in the experimental and modelling …