Failure Analysis on Corrosion Perforation of L245N Gathering Pipeline

A failed L245N gathering pipeline of an oil field was investigated and analyzed by macroscopic analysis, nondestructive tests, material tests (including chemical composition, metallurgical analysis, and mechanical properties), and microstructure analysis (including microtopography and x-ray diffraction) in this paper. It was concluded that the chemical composition and mechanical properties of the gathering pipeline accord with related standards, and the cause of corrosion was investigated. The results shows that the main reason of corrosion perforation of the gathering pipeline was the peeling off from the inner coating and the local corrosion caused by dissolved O and Cl− ions in the transport water occurs at the inner wall.