This paper presents results of an irnidazoline based (ECN) and Electrochemical Impedance Spectroscopy (EIS) inhibitor using the Electrochemical Noise techniques in a multiphase flow pipeline. ECN and EIS measurements were made simultaneously in a 101.6 mm I.D., 15m long acrylic pipeline using saltwater and carbon dioxide mixtures. Full pipe flow was studied for liquid velocity of 1.25 m/s and slug flow for Froude numbers 6 and 9. Experiments were carried out at a constant pressure of 136kPa and temperature of 40°C. The ECN signals and EIS spectra of blank and inhibition tests were obtained. The ECN technique is able to monitor the inhibitor film formation continuously. The current
noise fluctuation is correlated to the corrosion rate for both blank test and inhibitor test. The higher current fluctuation indicates higher corrosion rates. Different EIS spectra were obtained for blank and inhibitor studies. The simple charge transfer process was seen to occur for blank tests while charge transfer and diffusion processes were taking place under inhibitor effects. Keywords: Electrochemical Noise (ECN), Electrochemical impedance spectroscopy (EIS), corrosion inhibitor, multiphase flow