**4. Conclusions**

The corrosion inhibition effect of gum Arabic on the corrosion of carbon steel (N80) exposed in a high-pressure CO2-saline environment has been studied and the following conclusion can be drawn:


**Supplementary Materials:** The following are available online at http://www.mdpi.com/1996-1944/13/19/4245/s1, Table S1: Corrosion rate and inhibition efficiency obtained from weight loss measurements for the N80 carbon steel at various concentrations of GA and CO2 partial pressures after 24 h of immersion time, Table S2: Comparison of reported inhibition efficiency of some other corrosion inhibitors used in a CO2 saturated saline solution (3.5 wt.% NaCl), Table S3: Corrosion rate and inhibition efficiency obtained from weight loss measurements for the carbon steel (N80) carried out at 1.0 g L−1 of GA and CO2 partial pressures after 168 h of immersion time at 25 ◦C, Table S4: XPS analysis of sample steel surface after 24 h of immersion in test solution at PCO2 = 40 bar and at 25 ◦C in the presence of 1.0 g L−<sup>1</sup> of GA.

**Author Contributions:** G.P. conceived, designed, and performed the measurements, analyzed the experimental data, wrote and edited the manuscript; K.K. performed the XRD analysis; R.W. and A.B. performed the XPS. analysis; M.G. performed the SEM-EDS analysis. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** RW has been partly supported by the EU Project POWR.03.02.00-00-I004/16.

**Conflicts of Interest:** The authors declare no conflict of interest.
