This paper offers a brief review of methods that are used and presents different applications and experience from computer modeling of offshore cathodic protection systems. This comprises state-of-the-art software based on the Finite Difference Method ( FDM ), Finite Element Method (FEM), and Boundary Element Method (BEM) adapted for the calculation of current and potential distributions on complex, cathodically protected steel structures in seawater.
The numerical discretization procedures referred to above are combined with a data base and procedures for handling the electrochemical boundary conditions. In addition, software modules are included that handle the initialization of the computer models, definition of geometry, the numerical solution of the nonlinear discretized equations, and presentation of results.
In particular, this paper presents the principles and procedures used to handle boundary conditions. The procedures are based on basic corrosion theory and general experience as well as on laboratory and field tests. The author and his company have made use of extensive amounts of data obtained by in situ measurements of current densities and potentials on offshore platforms using proprietary electrical field gradient/current density systems. Thus the modeling results and predictions have been verified by field data.