|Title||A new versatile method for modelling geomagnetic induction in pipelines|
|Author||Boteler, D H|
|Source||Geophysical Journal International vol. 193, no. 1, 2013 p. 98-109, https://doi.org/10.1093/gji/ggs113|
|Alt Series||Earth Sciences Sector, Contribution Series 20120377|
|Publisher||Oxford University Press on behalf of The Royal Astronomical Society|
|Media||paper; on-line; digital|
|Subjects||geophysics; pipelines; pipeline feasibility studies; geomagnetism; geomagnetic fields; geomagnetic variations; magnetic induction; telluric field; telluric surveys; models; modelling|
|Illustrations||tables; flow charts; profiles|
|Program||Targeted Hazard Assessments in Northern Canada, Public Safety Geoscience|
Geomagnetic induction drives telluric currents in pipelines and creates fluctuations in pipe-tosoil potentials (PSP) that interfere with pipeline surveys and create conditions where
corrosion is more likely to occur. To understand the process of geomagnetic induction and determine the severity and location of troublesome effects requires the ability to model geomagnetic induction in realistic pipeline networks. Previous
modelling work, based on transmission line theory, has provided some insights into the process but has to be customized for each situation. This paper presents a new versatile modelling technique that can be easily applied to any pipeline network.
The essential part of the new method is the development of an equivalent-pi circuit for geomagnetic induction in a pipeline section. A complex pipeline network can then be represented as a set of equivalent-pi circuits that are combined to form a
nodal admittance network comprising connections between nodes and to ground from each node. The nodal admittance matrix method is then used to determine the voltages everywhere in the pipeline system. Sample results are presented for geomagnetic
induction in an example pipeline. It is shown how the modelling results can be combined with electric fields calculated from geomagnetic observatory data to determine the PSP variations that occur during geomagnetic disturbances.