Batch Corrosion Inhibitor FilmThickness Measurements Using Optical Profiler

Batch corrosion inhibitors are widely used for the corrosion control of production wells and pipelines in the oil and gas industry. Rules of thumb that incorporate film thickness, contact time and surface area are still commonly used to calculate the volume of batch inhibitor required for pipeline applications. A better understanding of the actual thickness of the inhibitor film on the metal and the impact of different variables on the film (e.g. inhibitor type, contact time, diluent type, dilution ratio, shear stress) will provide the basis for optimizing the application procedure and required batch frequency. Optical profiling (or white light interferometry) has long been a standard technique for non-contact, 3D measurement of surface topography. This method has now been extended to thickness measurements of semi-transparent batch inhibitor films. In this paper, the impact of several variables (i.e. inhibitor type, contact time, diluent ratio, shear stress) on batch inhibitor films was studied using an optical profiler to advance our knowledge of batch inhibitor application techniques and optimizing batch programs (e.g. film persistency, batch frequency).