Influence of a Porous Corrosion Product Layer on the Corrosion Phenomenon of Carbon Steel Pipelines

Assessing the severity of the internal corrosion of structures is of paramount importance in the oil & gas industry. Considerable effort has been deployed to implement an adequate electrochemical process of the corrosion phenomenon. However the influence of transport phenomenon trough a porous corrosion product layer (CPL) on the corrosion rate has not been studied extensively yet.

The transport phenomenon can influence the corrosion rate significantly by either limiting or accelerating the cathodic contribution. In this paper the general corrosion of a carbon steel under a porous CPL of siderite is studied and the influence of the transport phenomenon is examined using COMSOL Multiphysics ®. This model constitutes a first step and can be used for further development in order to assess the effect of either, a competitive diffusion trough a CPL or a conductive CPL, on the corrosion phenomenon.