The corrosion of the top flow in wet gas environment was studied in this work by using Electrochemical Noise Measurement (ECN). All the tests were carried out in a 3-inch I. D., 28-ft long acrylic pipeline. A CO2 or N2 wet gas environment was generated by using high-velocity gas to entrain
low-velocity seawater, which formed a annular-mist flow in the pipeline. The ECN results show less current and voltage noise fluctuation in a wet gas environment, which suggests a low corrosion activity.
The slope of voltage and current amplitude during low frequency domain in Fast Fourier Transform (FFT) plots indicates the corrosion type as uniform. The spectral noise impedance, Rsn, obtained from
FFT plots is high because the liquid film is very thin, therefore the corrosion activity of top flow in wet gas environment is relatively low. The results obtained from N2 and CO2 wet gas environment give a
further proof that ECN can be used to monitor the corrosion rates since the difference of the current and voltage between N2 and CO2 wet gas environment is evident. The increase of current and voltage noise
fluctuation with increase in gas velocity shows that the corrosion activity increases with increase in gas velocity.
Keywords: wet gas environment, electrochemical noise, top flow, corrosion activity