Inhibition of mild steel corrosion in CO<inf>2</inf> and H<inf>2</inf>S-saturated acidic media by a new polyurea-based material

Abstract

Oil well acidizing is a common practice used to boost oil well productivity in the industry. This practice, however, exposes the mild steel components of the wells to extremely harsh corrosive environments. Under such conditions, highly efficient inhibitors are used to minimize corrosion attack. In the present study, corrosion inhibition of mild steel in simulated acidic medium saturated with CO2 and H2S gases by a newly synthesized polyurea-based material (PUCorr-1) was investigated. Electrochemical studies supported with quantum chemical density-functional theory calculations and surface characterization revealed that PUCorr-1 adsorbs onto mild steel through a chemisorption mechanism yielding a stable protective film. The polyurea exhibited an excellent efficiency of 99.9% at a temperature of 50°C and a low concentration of 100 ppm, yielding a corrosion current density of 0.3 µA/cm2. In the presence of CO2 and H2S gases, PuCorr-1 exhibited a remarkable performance (>93% efficiency) making it a potential corrosion inhibitor in industrial processes that involve the use of acid solutions in the presence of CO2 and H2S gases.