Corrosion inhibition of steel pipelines in oil fields by N,N-di(poly oxy ethylene) amino propyl lauryl amide

The effect of non-ionic surfactant, namely N,N-di(poly oxy ethylene) amino lauryl amide, on the corrosion rate of carbon steel in produced water has been investigated by various corrosion monitoring techniques. The strong adsorption ability of the surfactant molecules leads to formation of a mono-layer, which isolates the surface from the environment and thereby reduces the corrosion attack on the surface. The adsorption process was found to obey the Langmuir adsorption isotherm. The potentiostatic polarization results clearly revealed that the inhibitor behaves as a mixed type. The maximum percentage inhibition efficiency (eta%) approached 94.87% in presence of 250 ppm of the inhibitor molecules. The effect of temperature on the corrosion rate of carbon steel was studied in the temperature range from 30 to 70 degrees C. Finally, scanning electron microscopy was used to examine the surface morphology of carbon steel samples in absence and presence of the inhibitor. (c) 2005 Elsevier B.V. All rights reserved.