In many service applications excursions in solution chemistry, temporary loss of inhibitor, or transient increases in temperature may give rise to localised corrosion. To test the return of inhibition when the loss is remedied, the use of an artificial pit has been investigated using simulations of cooling water and of of oil production formation water.
Results of inhibitor performance at slug flow in a 101.6 mm inner diameter horizontal pipeline. Electrochemical Impedance Spectroscopy (EIS) and scanning electrom microscope (SEM) techniques are used to reveal that the strong bubble impact, high shear stress and turbulent intensity are the reasons for a poor performance of inhibitor.
A novel evaluation technique, based on an artificial pit electrode, has been developed for inhibitor studies. The first example is of three generic inhibitors, against localised corrosion. The second is of three industrial inhibitors against existing localised corrosion on a north sea production platform