The object of this study is the steel main gas pipelines of the Lentransgaz company in the Leningrad Region. In the process of operation of gas pipelines is very important to control their condition. As a result of theoretical research, a physical and mathematical model of the geoelectric system gas pipeline-ground, which describes the distribution of cathodic protection leakage current density in the near-tube space based on the solution of the inverse problem of electrometry, is developed. When solving the inverse problem, the leakage currents are determined on the basis of ground measurements data, the values of which characterize the pipeline condition to a sufficiently accurate extent.
