Evaluation of Gradient Control Wire and Insulating Joints as Methods of Mitigating Induced Voltages in Gas Pipelines

Significant voltage levels can be induced in the gas pipelines due to power transmission lines in the areas where they share the same corridor, especially during a fault. These voltages can affect the operating personnel, pipeline associated equipment, cathodic protection and the pipeline itself. Quite often, mitigation is required to reduce these induced voltages to levels that are safe for personnel and integrity of the pipeline. This paper compares features of two mitigation methods: insulating joints and gradient control wire. An existing Agility pipeline is modelled using the specialized CDEGS software incorporating these two mitigation methods in order to compare the performance and costs. Results of this case study may be used as guidelines for designing the mitigation schemes for new pipelines.