Research Progress of Cu-Containing Antibacterial Oil Casing Steel for Microbial Corrosion Control

Microbial corrosion currently poses a serious threat to the safety of oil and gas extraction，and traditional protection technologies for oil casings are associated with certain environmental risks and high costs.Cu-containing antibacterial oil casing steel，designed through alloying，achieves long-lasting antibacterial performance by leveraging the multiple mechanisms of nano ε-Cu precipitates(such as cell membrane disruption，enzyme activity inhibition and DNA oxidative damage)，thereby offering an innovative approach to addressing microbial corrosion.The corrosion mechanisms of bacteria such as sulfate-reducing bacteria，iron-oxidizing bacteria and saprophytic bacteria were analyzed，and the antibacterial mechanism of Cu in Cu-containing antibacterial oil casing steel was described.The antibacterial performance primarily originated from the sustained release of Cu2＋from the nano ε-Cu phase and its multiple interaction mechanisms with microorganisms.Additionally，the influence of alloying elements on the corrosion resistance of Cu-containing antibacterial oil casing steel was summarized，and it was highlighted that the proper combination and content control of antibacterial and corrosion-resistant elements were crucial for enhancing the corrosion resistance of antibacterial oil casing steels.Moreover，the design concept and multi-scale regulation strategy of Cu-containing antibacterial oil casing steel were proposed，aiming to achieve synergistic optimization of antibacterial performance and mechanical properties.Furthermore，the hydrogen-induced cracking resistance of Cu-containing antibacterial oil casing steel was clarified，which was attributed to hydrogen permeation inhibition by CuS/FeS composite films and hydrogen trapping by nano ε-Cu precipitates.Besides，the research bottlenecks of Cu-containing antibacterial oil casing steel were summarized，including welding performance，copper-induced embrittlement and long-term antibacterial degradation.Future development directions were proposed，which should focus on composition optimization，process optimization，surface modification and green intelligent technologies，with the aim of providing guidance for the application of microbial-corrosion-resistant oil casing steels in the oil and gas industry.