This study summarizes the chemical effects that can occur during the corrosion process of carbon steel in a CO 2 -saturated aqueous environment. Particularly, it focuses more on the results that small chemical contaminations in the environment have on the corrosion process. Underground waters present complex chemistry with several different dissolved ions (chlorides, carbonates) even in high concentrations that impact substantially the corrosion rates of these materials. Moreover, gas impurities present in the gas mixture, such as oxygen in carbon capture and storage applications, constitute a supplementary form of significant contamination in the CO 2 -saturated aqueous environment.In particular, the effect on both electrochemical reactions and corrosion product layer is examined for several chemical species that are commonly present either in the gas mixture or in underground waters.Carbon steel remains the most popular material for industrial applications because of its lower cost with respect to corrosion-resistant alloys. [1,2] Nevertheless, inferior corrosion resistance performances lead to a deep investigation of the corrosion process in various environments. Furthermore, numerous actions were adopted to prevent corrosion rate value to reach unsustainable costs, such as corrosion inhibitors, cathodic protection, and coatings. In relation to a deep knowledge of the corrosion mechanisms, each method of protection has to be designed carefully to successfully address the specific corrosion problem.This bibliographic report concerns the issues related to carbon steel corrosion in a CO 2 water solution, particularly, the effects of some chemical elements of the solution that can impact the mechanism of the electrochemical reactions of the corrosion process. Their effects may be direct or indirect through modifications of the nature of the corrosion product layer (CPL).Understanding and mitigation of CO 2 aqueous corrosion of carbon steels are a major challenge in many industries, such as oil production (including enhanced oil recovery [EOR]), CO 2 capture, transportation, storage and utilization, biofuels refining, and geothermal energy production. Considering the oilfield brines and oils, their composition is quite complex, with a plethora of chemicals that can interact with carbon steel. [3,4] Therefore, a small selection of common water components and those presenting new challenges for carbon capture and storage and geothermal energy production are presented.
