Unexpectedly large potential fluctuations, in the range of +/- 12-15 volts, have been experienced on relatively short pipelines. These fluctuations have been related to Geomagnetic Induced Currents (GIC, or Telluric Currents). Geomagnetic activity together with the pipe-to-soil potential have been recorded and correlated to each other. In addition,
measurements of instant off potentials together with flow of current to coupons, distributed along the pipeline route were carried out. Laboratory studies have also contributed to a better understanding of the corrosion risk from GIC.
Keywords: Telluric current, Corrosion, Pipeline