The research of corrosion behaviour and protection of 3Cr pipes in gas injection wells with oxygen flooding

Aiming at the corrosion and protection of pipes in the development of wellbore with oxygen-containing gas, systematically carried out dynamic corrosion experiment research under different O2content conditions of gas injection wells, and clarified the corrosion rate of pipes in the life cycle of the development wellbore with O2-containing gas, and is a life-cycle anti-corrosion material Selection and anti-corrosion measures provide data support and reference. Simulated the wellhead, mid-well, and bottom working conditions of an oilfield in Bohai Sea to conduct dynamic corrosion experiments of gas injection wells under different O2content conditions, using O2-containing gas components (5%, 10% and 21%), the experiment period is 14d. The bottom hole working condition is selected to complete the study of the variation law of corrosion rate with time, the experiment period is 3d, 14d, 30d, and the experimental material is 3Cr pipe. According to the dynamic corrosion experiment results of gas injection wells, it can be seen that the corrosion rate of 3Cr pipes exceeds the material selection control line and cannot be used directly in given working conditions. It is recommended to use 3Cr pipes and internal coatings to prevent corrosion or use 3Cr pipes to inject corrosion inhibitors.