Acoustic Reflectometry for Gas Pipelines – Monitoring Features in Gas Pipelines Using Acoustek

This paper will provide an overview of a patented acoustic technique known as Acoustek ® that has been developed to detect features, such as blockages and leakages in gas pipelines. The technique involves injecting an acoustic, or pressure pulse into the gas within the pipeline. This acoustic pulse will travel as a plane wave along the pipeline and will be partially reflected wherever there is a change in acoustic impedance. Such an impedance change will occur where there is, for example, a change in the internal cross sectional area of the pipeline. By measuring the reflections produced as the acoustic wave travels along the pipeline, together with knowledge of the speed of sound in the pipeline, the location of features, such as blockages, holes, valves and buckles can be accurately detected and located. The technique is non-invasive and in tests it has been shown to be capable of surveying both small and large diameter pipelines over distances up to approximately 10km. It is hoped that future development will take it considerably further.