A novel technique of detecting CUI based on electrical impedance spectroscopy and the results of its application from a 15-month long field trial in Norway


This paper reports on a disruptive new technology for the non-invasive detection and monitoring of Corrosion Under Insulation (CUI). This system has already been validated on a smaller scale during separate 15-month-long field trials in Norway between November 2016 – February 2018 and the results are presented.

The principle of operation is Electrical Impedance Spectroscopy (EIS). It is deployed as a distributed, interconnected, network of separate in-situ sensors, with a single EIS sensor located at each node of a network of inter-connected sensors that form a modular Supervisory Control and Data Acquisition (SCADA) system. This arrangement provides full condition-monitoring coverage of any size of distributed pipeline network and remote, real-time, surveillance of the instantaneous condition of any individual section of the pipeline network is provided via wireless telemetry.

This arrangement provides continuous, minute-by-minute, 24/7, pinpointed CUI detection and condition health monitoring information - without the need for removal of insulation, mantling, or other any human intervention whatsoever.  Another key commercial advantage of this system, is that it can be readily “retro-fitted” onto existing ageing assets and infrastructure.