Reliability Evaluation of Flexible Composite Pipe Joints for CO₂ Flooding Production Conditions in Xinjiang Oilfield

A set of reliability evaluation method for non-metallic pipe joint was proposed. The crevice corrosion test of flexible composite pipe metal joint was carried out by high temperature and high pressure autoclave, and the surface morphology of the test piece was observed by 3D depth field microscope. The performance of the sealing washer before and after the test was analyzed by Fourier infrared spectrometer and Shore hardness tester. The reliability test of the whole pipe seal was carried out under extreme conditions. The results showed that the corrosion rate of the joint pipe was 0. 119 4 mm/a in the multi-phase medium environment with temperature of 60℃ and CO₂ partial pressure of 1. 5 MPa, which belonged to the medium corrosion degree. After adding the corrosion inhibitor, the corrosion rate decreased significantly and was lower than 0. 076 mm/a. Under extreme conditions, polytetrafluoroethylene washer and nitrile rubber washer were not damaged, and the joint performance was stable and reliable.