Corrosion Reason Analysis of Ground Gathering Pipelines in High Flow-rate Gas Condensate Field

摘要

Ground gathering pipelines in a high flow-rate gas condensate field were seriously corroded and became perforation only after five months operation. The results of witnessed inspections and analysis showed that T-branch pipe, Elbow and weld were corroded most seriously. The main features of the corrosion were trench-like corrosion pits. In order to clarify the reasons for corrosion so seriously, XRD, SEM, EDS were used to test the film of sample which was taken from the field. The results showed that wall thinning of pipelines was mainly caused by CO_2 corrosion combined with erosion and the corrosion product was mainly composed of FeCO_3.