A Modified Potential Attenuation Equation for Cathodically Polarized Marine Pipelines and Risers

摘要

A previously developed first principles based equation for potential attenuation along marine pipelines and risers with multiple, equally spaced, identical galvanic anodes was modified to accommodate an error in its derivation. Both the original and modified equations account for the electrolyte (anode), coating, polarization, and metallic path resistances and, as such, represent improvements over previously available representations. Coordinate Mapping Based Finite Difference Method (CoMB-FDM) solutions are presented for different pipe and cathodic protection conditions; and to the extent possible, the accuracy of these is verified.