Improvement and application of pipeline cathodic protection technology in Zhou-X Gas Gathering Station of Zizhou Gasfield

Zhou-X Gas Gathering Station of Zizhou Gasfield is located in an area which is characterized by dry climate, high soil resistivity, frequent network transformation/expansion, and high salinity and Cl^- in water. Consequently, original design of cathodic protection cannot meet the demands of pipeline protection in later stages. This paper reveals the existing problems in cathodic protection system of Zhou-X Gas Gathering Station, including high resistance in auxiliary anode, failure of insulation joints, damages in cables and delays in export regulating, and analyzes the causes for its failure by testing insulation joints using potential method, PCM leakage measurement and grounding resistance measurement techniques. Moreover, some technical solutions, such as deep-well anode, uplifting the height of insulating flange, spraying insulating coating on inner walls, connecting cables with wire connector and using intelligent data transmission, are proposed to solve above problems, and eventually improve the corrosion resistance of gas pipeline.