Abstract: With the static high pressure and high temperature kettle and the SEM method，and based on the analysis between the supercritical fluid CO₂ and the interaction of the water and oil, the corrosion experimental study for the N80 steel grade in the supercritical fluid CO₂ was investigated. The results were show that the C0₂ corrosion was found in the SCF-CO₂ gas phase. In the liquid phase, the corrosion rate was accelerated with the increas-ing of pressure; it got the peak at 12 MPa and then down. In the medium of pure water, the corrosion rate in the gas was agreed with the corrosion rate in the liquid at 12 MPa, the tubercules were observed in corrosion film. The corrosion rate in the liquid was accelerated if the civde oil content was 30%.The tuber-
rules and poles were found in the corrosion film together. The C0₂ corrosion of steel was restrained with the increasing of the oil content.

Key words: SCF-C0₂corrosion, corrosion rate, oil and water blending fluid, cormsion film