Adsorption Behavior and Inhibition Performance of Imidazoline Quaternary Ammonium Salt on N80 Steel in Simulated Oilfield Water with Saturated Carbon Dioxide

A kind of imidazoline quaternary ammonium salt inhibitor was synthesized with benzyl acid,diethylenetriamine and sodium chloroacetate as the starting materials.The structure of as- synthesized product was characterized by infrared spectrometry.The adsorption behavior of the inhibitor on N80 mild steel in simulated oilfield water with saturated CO_2 and its inhibition performance were tested by static weight- loss experiment,electrochemical experiment and apparent observation,and the relationship between the adsorption behavior and inhibition performance of the inhibitor was examined.Results indicated that the concentration of the inhibitor,temperature and corrosion time had significant influences on the inhibition performance towards the mild steel in simulated oilfield water with saturated CO_2.The inhibitor was able to form a solid monomolecular adsorption film on steel surface thereby preventing the corrosive medium from contacting with the metal.Moreover,as-synthesized inhibitor was a mixed-type inhibitor which was dominated by cathode control at lower concentrations and by anode control at higher concentrations.It was able to form an adsorption film on metal surface and change the interface state of the metal thereby func-tioning to inhibit corrosion,and its inhibition performance tended to enhance with elevating concentration.