Performance of Quebracho extract as eco‐friendly corrosion inhibitor for SAE 1010 steel in the oil field environment

The inhibitive behavior of Quebracho tannin extract on SAE 1010 steel corrosion in the acidic media is investigated. Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) are first used to determine the inhibition efficiency of Quebracho in 0.1 M HCl solution to identify the best extract concentration to subsequently evaluate the inhibitor activity in CO2‐rich aqueous solution at high pressure (15 MPa) and high temperature (70°C). Polarization curves revealed that Quebracho extract acted as cathodic inhibitor and that the inhibition efficiency is dependent on the extract concentration. The EIS measurements and SEM analysis showed that the inhibitor had been adsorbed on the steel surface. The inhibition efficiency of Quebracho in CO2 medium was similar to the 0.1 M HCl, reducing expressively the corrosion rate. The SEM images and X‐ray diffraction analysis showed that iron carbonate was the main corrosion product formed on the metal surface in CO2‐rich environment in the presence of Quebracho. Besides, the corrosion scale was thinner and more compact in the presence of inhibitor. Quebracho extract is a cathodic inhibitor in 0.1 M HCl medium for SAE 1020 steel and the inhibition efficiency is dependent on the extract concentration. The inhibition efficiency in CO2 medium was similar to the 0.1 M HCl, and the Quebracho decreased expressively the corrosion rate. The iron carbonate was the main corrosion product formed on the steel surface in CO2‐rich environment in presence of Quebracho.