The application of corrosion inhibitors (CI) to producing oil and gas field systems is one of the most common practices of corrosion control. Acid stimulation fluids such as hydrochloric acid (HCl) and organic acids has high calcite and dolomite dissolving power; however, pumping HCl downhole during acid stimulation process particularly at elevated temperatures can cause severe corrosion. Therefore, the addition of corrosion inhibitors is indispensable to protect the metal from corrosion. More inhibitors that are efficacious are still needed to provide better protection against the corrosion.
Two new bisquaternary ammonium salts; 1,4-Benzenedimethanaminium, N,N'-didodecyl-N,N,N',N'-tetramethyl-, dichloride (CI-1) and 1,4-Benzenedimethanaminium, N,N'-dihexadecyl-N,N,N',N'-tetramethyl-, dichloride (CI-2) as corrosion inhibitors were successfully synthesized, characterized and electrochemically evaluated for their corrosion inhibition efficiency in 1 M hydrochloric acid (HCl) solution on API 5L X60 low carbon steel. Potentiodynamic polarization measurement revealed mixed type inhibition mechanisms of the synthesized inhibitors. Inhibition efficiency of CI-1 increase with increase in concentration 2.0 to 20.0 ppm while CI-2 efficiency does not go beyond 2 ppm. Adsorption isotherm of CI-1 was found to deviate from Langmuir isotherm due to its interaction on low carbon steel and the interaction was approximated by Temkin isotherm. Analysis of the adsorption of CI-1 on API 5L X60 involve both physisorption and chemisorption.