Potential and current fluctuations on oil and gas pipelines attributed to telluric currents have been observed for many years by corrosion control personnel when conducting routine cathodic protection performance surveys.
The impact of these geomagnetically induced currents has generally been considered more of a nuisance when measuring cathodic protection parameters than a serious corrosion concern.
Boteler has shown that the telluric voltage induced on a pipeline can be calculated using distributed source transmission line equations. He has shown that the magnitude of the telluric voltage (V t) is not only a function of the direction and magnitude of the electric field but also directly dependent on the length and the pipe’s resistance to earth. These calculations when applied to modern well coated pipelines, suggests that telluric current effects may not be as innocuous as originally thought for pipelines located in Canadian latitudes.
