Corrosion inhibition behavior of synthesized schiff base compounds for steel pipelines in oil and gas wells applications

In this work, corrosion inhibition behavior of synthesized schiff base compounds has been studied for API-۵L-X۶۵ steel in hydrochloric acid solution by potentiodynamic polarization diagram, scanning electron microscopy, and impedance spectroscopy (EIS). To simulate the oil and gas well acidizing fluid, hydrochloric acid solution was employed as corrosive medium. Potentiodynamic polarization curves showed that compounds decreased both the anodic and cathodic reaction currents through adsorption and blocking the active corrosion sites. The inhibition efficiency enhanced with increasing inhibitor concentrations. EIS data were investigated by equivalent circuit and indicated that with increasing inhibitor concentration, the resistance of charge transfer enhanced and the capacitance of double layer reduced. The obtained data proposed that the inhibition efficiencies were increased for inhibitor in the absence of alkyl addition. The geometrical steric hindrance offered by the alkyl groups in the schiff compounds plays an important role in its corrosion inhibition properties. Scanning electron microscopy was used to study the steel surface with and without inhibitors.

Keywords:

Corrosion , Inhibitor , Impedance , schiff base compounds , Well acidizing fluid