Non-intrusive corrosion-erosion monitoring for subsea applications

Abstract

Detection and monitoring of corrosion and erosion are essential prognostic means in preserving material integrity and reducing the life-cycle cost of industrial infrastructure, ships, aircrafts, ground vehicles, pipelines, oil installations, etc. Even topside, the operating conditions can be extremely difficult, facing problems like pipe surface roughness, fluid loading, temperature variations, and a host of other factors that make development of a robust wall thickness assessment tool a challenging task. Deploying a monitoring system subsea makes the application even more demanding when factors such as high pressure and limited access must be taken into account. The ClampOn Corrosion-Erosion Monitor has already been successfully installed at several locations topside and is now in its final stages of the subsea development. Non-invasiveness, high repeatability and high coverage are among its advantages, making it an excellent candidate for subsea use. The technology is based on the dispersion of ultrasonic guided wave modes. By using electromagnetism these waves can be transmitted through the pipe wall without the sensor being in direct contact with the metallic surface. It is installed on the outer pipe wall to produce real-time wall thickness information, not as a spot measurement, but as a unique average path wall thickness.