A recent trend in the field of pipeline monitoring has been the utilisation of an optical fibre based distributed acoustic sensing (DAS) technology, for the purpose of security monitoring of buried pipelines [1–3]. The technology comprises an interrogator, connected to an optical fibre cable, which is interrogated to acquire coherent Rayleigh backscatter. Localised environmental vibrations may result in a proportional strain of the fibre. This strain results in a localised optical path length variation, resulting in a phase distortion in the measured signals. Application of signal processing techniques infer the characteristic of the originating stimulus, and thus identify and locate the source activity of interest. Activity may arise as a result of ground excavation, vehicular movement, or similar in the vicinity of the pipeline.
Researchers are now studying the possibility of utilisng this technology for the purpose of pipeline leak detection monitoring . This paper provides a review of one such programme of work.
Results are presented for a permanent installation, where signatures relating to leaks were identified, and located in the resulting DAS data. Results are provided relating to liquid leaks, where product was emitted at a flow rate of 20.0l/minute and operational pressure 20.0bar.