Signal processing for corrosion assessment in pipelines with ultrasound PIG using matched filter

Abstract

This work describes the development of an algorithm that uses ultrasound to evaluate the degree of corrosion in pipeline walls. The developed algorithm was implemented in a dedicated digital circuit that can be embedded in ultrasonic pigs for pipeline corrosion inspection. The algorithm is based on the mathematic model known as matched filter. It also incorporates a peak detection method for the localization of ultrasound echoes, originated from the signal reflections in the pipeline walls. One of the problems is the determination of the signal (and filter) that should be used, but using a signal design approach, a large number of possibilities could be analyzed so that only a few had to be tested in experiments. Finally, the best signals were used to inspect a sample made of a corroded pipeline section, and the results were analyzed. The detection of the first wall showed promising results when compared to the results of a tridimensional inspection of the same walls. It was possible to reconstruct the profile of the internal wall with good likelihood, even in badly corroded areas. The detection of the second wall showed some satisfactory results on low corrosion levels, but showed some problems with high corrosion levels, compromising the direct measurement of the pipeline wall thickness.

Ultrasound-Based Smart Corrosion Monitoring System for Offshore Wind Turbines

“…The inspection devices are usually "once-off" measurements that cover a given period of time (according to maintenance schedules), while the monitoring devices involve very frequent measurements that must detect small fluctuations in the advancement of corrosion in order to be used as input for a general assessment of corrosion [27]. Several previous works have been reported to assess corrosion in pipelines using ultrasounds [28].…”

Using UHF-RFID Signals for Robot Localization Inside Pipelines

“…Depending on the size of the pipe, average corroded pipe repair costs range from A$400 to A$4000 per metre. There are several inspection methodologies based on pulsed Eddy current sensors [2], laser profilers and stereo vision [3], electrical resistivity sensors [4], fibre optic sensors [5], drilling mechanisms [6], ultrasound sensing [7], infrared radiometers [8] to name a few are currently used to identify hot spot corrosion zones in the water utility pipelines. Based on the level of pipe degradation, the water utilities either choose to replace that respective section of the pipe or apply protective pipe linings to extend the service life of the pipe section [9].…”