Modeling of electromagnetic fields of pipelines cathodic protection systems in horizontally layered medium

Abstract

Design of cathodic protection systems of the trunk pipeline is regulated by current standards, based on the condition of uniformity and constancy of the electric conductivity of the multilayered half-space surrounding the pipeline. The current mathematical models of such systems also use an average value of the medium electric conductivity, which does not fully reflect the actual characteristics of the soil, in which the pipeline is laid. The authors present a method that accounts for the thickness and electrical conductivity of individual beds in a vertically-inhomogeneous, horizontally layered medium (the most practically appropriate case). Using method of computational experiment, the authors showed the importance of accounting for the effect of the medium layers structure and electrical resistivity on the protective voltage of the electric current in the cathodic protection system for underground trunk pipeline and studied the magnetic field sensitivity dependence on the insulation resistance of the pipeline defect-containing segments and on the altitude of data acquisition.