Towards the estimation of Space Weather-related corrosion on pipelines

Geomagnetically induced currents (GIC), increased during space weather events, are able to interfere with pipeline corrosion protections systems and potentially can increase corrosion of the pipeline steel.

Methods, widely used for the evaluation of annual corrosion rates, are based on exposure of steel to constant currents and voltages (DC), or alternating currents and voltages of a constant frequency (50 Hz or 60 Hz), while GIC are characterised by a continuous frequency spectrum, with the range of frequencies from 10^-5 Hz to 1 Hz.

This paper introduces the methods for use in the estimation of corrosion rates on pipeline steel produced by GIC (commonly referred to as “telluric currents” in the pipeline industry) and provides results calculated for specific time periods with use of available recordings made on pipelines at the times of geomagnetic storms. As well, annual cumulative corrosion rates are estimated based on the modelling of pipeline currents and voltages.

In addition to the detailed presentation of the methods utilised, a comparison of corrosion rates produced by telluric variations on non-protected and protected pipelines located in mid- and high-latitudes is presented.