Performance of a Novel Corrosion Inhibitor Used in Implicit Acid Completion Fluid

The implicit acid completion fluid(IACF) can effectively dissolve the blockages of oil reservoir and improve the permeability,therefore can increase the output of oil wells.However the casing and tubing pipes will be corroded seriously by the IACF.The effects of temperature,the concentration of chelating agent HTA on corrosivity of the IACF and the inhibition of three corrosion inhibitors on corrosion behavior of N80 steel in the IACF were studied by weight-loss method and potentiodynamic polarization.The results showed that the corrosion rate increased and pit corrosion tended to be more serious with increasing the temperature and the HTA concentration.Corrosion could be effectively inhibited by adding corrosion inhibitors in the IACF.Among the three corrosion inhibitors,CA101-2,a polyamide corrosion inhibitor,exhibited the best anti-corrosion performance.Corrosion rate of N80 could lower to be 0.056mm/a by adding 1% CA101-2 in the IACF containing 0.2% HTA.Potentiodynamic polarization measurement showed that CA101-2 mainly retarded the hydrogen evolution and belonged to a cathodic-type corrosion inhibitor.