Siting Transmission Lines Adjacent to Underground Pipelines

摘要

Common corridor utility construction has become a common practice in the United States due to many factors including urban congestion, convenience, and cost. However, there are hidden dangers in doing so. Federal regulations require O&G pipeline operators to apply effective dielectric coatings to the pipeline's exterior that is supplemented with cathodic protection. Thus the pipeline becomes the secondary of an air core transformer. Depending on the geometry of the parallelism, lethal voltages and currents may be induced to the pipeline. Additional problems or concerns include damage to coatings, corrosion of the: pipe at holidays in the coating, damage to the pipe wall via arc burn, and the possibility of fire or explosion in the event of a through the wall arc burn. All of these undesirable events have occurred on pipelines in the past. This paper describes the electro-physics of the various phenomena involved with common corridor. Various mitigation schemes are presented. A strong case is made for Induced AC mitigation studies before the power transmission line route is established and the common corridor geometry is finalized.