CRUDE OIL CHEMISTRY EFFECTS ON INHIBITION OF CORROSION AND PHASE WETTING

摘要

The effect of crude oil chemistry on corrosion processes is poorly understood. A simplemechanistic model that takes into account the combined effects of corrosion inhibition andwettability alteration, due to the adsorption of polar molecules onto the steel surface, is proposed.While the inhibition effect is dominant in oil-water stratified flow, the wettability alteration isdominant in turbulent flow. Consequently, both effects have to be taken into consideration inorder to predict corrosion in oil-water pipe flow. The objective of this study is to identify chemicalspresent in crude oil which have an effect on inhibition and wettability. The likeliest molecules toadsorb onto a metal surface are polar compounds. Nine polar compounds containing nitrogen,sulfur and oxygen have been studied. Corrosion rates were recorded, the change of the steelwettability has been quantified and the mass adsorbed onto the metal surface measured with aquartz-crystal-microbalance. Results show that certain groups of chemicals have stronglyinhibitive effect on corrosion and wettability while others had only a negligible effect.