Fracture Cause Analysis on Thermal Recovery Steam Injection Pipeline of Heavy Oil Well

A high temperature and high pressure steam injection pipe was fractured in the run-time in a oil field steam injection station. The fracture causes of the steam injection pipe were analyzed by means of chemical composition analysis, mechanical property testing, metallographic examination and so on.The results showed that the fracture initiated in mechanical damage on pipeline surface; the fracture cause was that the wall of pipeline was thinned by oxidation corrosion after a long run; furthermore, the microcracks and holes had occurred in the corrosion layer of outer wall, these led to the performance of pipeline can not meet the technical requirement, under the action of the two factors, the pipeline was fractured at last.