Study on Mechanism and Protection of Lightning Overvoltage of Anticorrosive Layer of Buried Oil and Gas Pipeline Adjacent to Power Line

With the continuous construction of social integrated energy lines, the intersection and proximity of power overhead lines and natural gas pipelines are becoming more and more frequent. The problem of lightning overvoltage in the case of adjacent crossing has attracted wide attention. Aiming at the problem of lightning overvoltage protection of anticorrosive coating of natural gas pipeline near high voltage line, firstly, ATP-EMTP software is used to calculate the characteristics of lightning current into the ground of tower near natural gas pipeline. Combined with COMSOL Multiphysics finite element software, the calculation model of lightning overvoltage of natural gas pipeline and its anticorrosive coating is established to clarify the output mechanism of pipeline body potential and anticorrosive coating potential difference. Secondly, the influence of lightning current amplitude, soil resistivity and “pipeline-line” spacing on pipeline overvoltage is analyzed by simulation. Finally, the lightning breakdown protection method of pipeline anticorrosive coating under the action of grounding current dispersion is proposed. The voltage limiting effect is verified by simulation examples and the construction suggestions of actual reconstruction project are put forward. The conclusion of this paper can provide reference for the design, construction and safe operation and maintenance of oil and gas pipelines.