Anomalous geoelectric potential variations observed along a gas pipeline section in Argentine, possible intensification with variations of the Earth’s magnetic field

Abstract

Significant anomalous geoelectric potential variations have been observed in a section of the NEUBA II gas pipeline along its route in the district of Saavedra, near the area of Goyena, province of Buenos Aires (Argentine), where it goes through major lithological, edaphological and hydrological variations. Detailed research was conducted, showing that these disturbances may be intensified with variations of the Earth’s magnetic field, during a magnetic storm, as the pipe-to-soil potential (PSP) values remained constant for weeks and then fluctuations from 0.1 V to 0.15 V were recorded in various parts of the pipeline. On the other hand, to provide another analysis of these variations, models based on the distributed source transmission line (DSTL) theory were used, proposing a uniform geoelectric field along the pipeline route. A design was proposed that would allow modeling the response of the pipeline to variations of induced geoelectric fields, taking into account their intensification based on points of discontinuity due to subsoil characteristics or differences in its structure. Good consistency was achieved between the observed and modeled PSPs. The analysis and monitoring of these PSPs is a useful tool to identify the potential risks caused by geomagnetically induced currents in the pipes that would increase the effects due to the structure or the environment in which it is buried.