Corrosion Behavior of 316L Stainless Steel in Oilfield Water Injection Environment

The corrosion behavior of 316L stainless steel was studied in simulated reinjection water of oilfield injection system with total pressure of 20.2 MPa and degree of mineralization up to 105 mg/L by electrochemical testing, corrosion immersion testing, surface analysis. The effects of pH, temperature, Cl^- content and other corrosion factors on its corrosion behavior were analyzed. The results show that the 316L stainless steel had excellent resistance to uniform corrosion in simulated reinjection water. After 30 days of corrosion immersion, slight pitting happened on the surface of the steel sheet, and the presence of oxygen increased the probability of pitting. The pitting potential of 316L stainless steel in the simulated reinjection water was 0.036 V and the critical pitting temperature was 16 ℃. The uniform corrosion rate of 316L stainless steel was obviously affected by pH, temperature and Cl^- content, and was less affected by the presence of oxygen in solution.