BEM simulation on the influence of dispersion currents on buried pipes

Abstract

The aim of this paper is to provide a method for modelling the influence of stray currents on buried pipes, using as calculation the boundary element method (BEM), using the module dedicated to corrosion in COMSOL Multiphysics software, which allows investigation both macroscopically and microscopically of corrosion processes. Dispersion currents, often called stray currents, are considered currents that follow little-known trajectories in the ground, but which can affect underground gas pipelines. Their sources are external to the pipes and contribute to the lowering of the anodic potential up to values to which the accelerated anodic dissolution of the metal occurs. For the simulation, the geometric modelling of a soil cube was used, in which pipes of different sizes are inserted, protected or not by a polyethylene protection state, in different positions and different burial depths. Using a calculation algorithm that is based on the boundary element method, the dynamics of the cathodic protection for the buried gas pipes in the presence of stray currents can be modelled.