Corrosion Protection of Steel Pipe Lines used in Oil and Gas Industry of Oman

Abstract

This paper investigates experimentally the influence of different types of coatings with nano-additives on the corrosion behaviour of steel pipe lines used in petroleum industry of Oman. The investigation was carried out with several types of coated samples to examine the rate of corrosion in pipe lines made of low alloy steel. Different coatings such as organic, zinc, aluminium paints and electroless nickel-phosphorous with copper oxide as nano-powder are coated on the samples. The samples were prepared from the actual pipe lines used in oil industries of Oman. During the investigation, corrosion rate and its behaviour were studied. Electroless nickel baths were prepared with Nickel Chloride as source of nickel and Sodium Hypophosphite as reducing agent. Samples were prepared to conduct atmospheric exposure test, wet/dry test and Potentiodynamic test. Before the exposure test, surface roughness of the samples was measured. Uniform coating thickness was maintained on all samples. Characterization was done through scanning electron microscope to study the surface morphology and Energy-dispersive X-ray to examine the percentage to weight ratio of different elements supported with hardness test. The coating paint group investigates aluminum paint followed by zinc paint and then organic paint resulting high resistant to the corrosion rate. The second group of samples that was coated with electroless nickel- phosphorus (EN-P) paint in which two types of coatings were used. EN-P without nano additive particles and with nano CuO additives. A novel method is identified in which EN-P with nano CuO additives significantly improved the corrosion resistance of steel samples and resulted in protection of the external surface of pipe line. The complete experimental details, results and analysis are reported in this paper.