Effects of corrosion defect and tensile load on injection pipe burst in CO2 flooding.

Highlights • The defect depth played a more dominant role in pipe burst than did the defect length. • The pipe burst pressures were reduced approximately 20–30% after a 30 MPa axial tensile load was added. • Burst pressures were much lower in the general defect tests compared to the groove defect tests with the same defect depth. • Failure began as instantaneous ductile rupture and extended as brittle rupture. • The higher the burst pressure, the stronger the BLEVE effect. Abstract Highly pressurized injection pipelines in CO 2 flooding often suffer from different types of corrosion defects and mechanical stresses and can easily cause serious damage to the environment. Currently, the descending rule of pipe burst pressures under different defect parameters and tensile loads has not been studied systematically. In this study, a section of injection pipe was used to simulate the burst process of pipe with groove and general corrosion defects. The crack appearance showed that the fracture began at the centre of the longitudinal defect line as an instantaneous ductile rupture and then extended along both sides as a rapid brittle rupture under high stress. The burst pressure in the groove corrosion defect tests showed that the defect depth played a more dominant role in pipe burst than the defect length did, and when a 30 MPa axial tensile load was added, the pipe burst pressure was reduced approximately 20–30%. In general corrosion defect tests, the burst pressures were generally much lower than the groove corrosion defect tests produced, and when adding the axial tensile load, the burst mode changed. Moreover, the value of the burst pressure can be a sign of BLEVE (boiling liquid expanding vapor explosion) severity. [ABSTRACT FROM AUTHOR]