Corrosion inhibitor in CO2-O2-containing environment: Inhibition effect and mechanisms of Bis(2-ehylhexyl) phosphate for the corrosion of carbon steel

The corrosion inhibition of carbon steel in CO 2 -O 2 -containing environment is one of the biggest challenges in flue gas injection for enhanced oil recovery. Herein we report the possibility to use Bis(2-ehylhexyl) phosphate (BEP) to inhibit the corrosion in CO 2 -O 2 -containing solution and simultaneously the inhibition mechanisms are unmasked. The results show that the corrosion is greatly inhibited with 500 ppm BEP in 1 wt% NaCl solution with 0.02 MPa CO 2 and 3 mg/L O 2 . BEP could interact with Fe and corrosion products via the formation of P-O-Fe bond and P-Fe bond to generate a barrier layer, thus, offering a protective performance.