Effective Management of Cathodically Protected Plant Facilities in a Complex Gas Processing Plant

摘要

Oil and Gas industries always have complex buried piping networks inside their plant facilities. Buried piping and other structures usually get multiplied due to frequent expansion of the plant facilities over years. Most of the buried piping is protected by dedicated impressed current Cathodic Protection (CP) systems installed during each expansion project. Furthermore, most of the buried piping is usually tied in with existing piping during the expansion projects, mostly without electrical isolation joints. No attempt is usually made by the CP designers to utilise the existing CP systems. Even though the buried piping is protected by distributed shallow groundbed anode systems, they are influenced by other CP systems and existing piping network due to shallow water table and associated low resistivity soil. Adding to the complexity of the piping network and the multiple CP systems, installation and commissioning of CP systems are usually handled by different personnel who usually are not fully aware of the importance of the CP systems, its installation, and proper commissioning. Experience shows that CP systems are not given its due importance during the project implementation, sometimes with improper design, installation and commissioning data. The scope of this paper is to brief the methodology used to ensure reliable operation of the cathodic protection system in order to protect the buried, immersed structures such as piping, tank bottoms, vessels and concrete structures exposed to marine atmosphere from external corrosion.