P110S 钢在高矿化度油田水环空保护液中的 腐蚀风险评价.

Using high-salinity oilfield water as the annulus protection liquid base fluid can easily increase the risk of corrosion and cracking of tubing and casing steel. Therefore, it is necessary to evaluate the corrosion risk of P110 S steel in the oilfield water annulus protection liquid. Firstly, the chemical components of oil field water and P110 S steel were analyzed. Then, the field conditions were simulated by using a high-temperature autoclave. The weightlessness corrosion and four-point bending experiments were carried out under the temperature of 200 ℃, CO2 partial pressure of 10 MPa and H2S partial pressure of 2 MPa, and the morphology and composition of corrosion products was analyzed by using SEM and EDS. Finally, the cross-section of the sample was analyzed. The results show that P110 S steel does not suffer from stress corrosion failure under high temperature and highacid conditions. The corrosion rate is 0.098 5 mm/a, severe pitting and local corrosion can be observed on the surface of the sample. Cross-sectional analysis shows that the thickness of corrosion product film on the sample surface is 63 μm, and the metal matrix is corroded seriously. P110 S tubing and casing steel faces a greater risk of corrosion failure under this working condition. In order to suppress the corrosion damage of the pipes, it is recommended to use fresh water or low-salinity well site water as the annulus protection liquid base fluid. [ABSTRACT FROM AUTHOR]