Method and apparatus for pattern match filtering for real time acoustic pipeline leak detection and location

摘要

A method and apparatus is provided for detecting and locating leaks in a pipeline. Pattern match filtering is used to reduce false alarm rate, increase sensitivity and improve leak location accuracy, while quickly detecting leaks by the acoustic signal generated from a leak event in pipelines containing gas or liquid under pressure. The pattern match filter technique detects a pressure wave generated by a leak, but discriminates against background noise and pressure disturbance generated by other non-leak sources that might otherwise be detected as a leak. The pattern match filter derives a sharp peaked output from the signal of the expansion wave which allows for a distinctive point of reference for a time stamp. This provides for improved accuracy in leak location calculations. The pattern match filter is incorporated into site processors located at multiple points along a pipeline, and at a central node processor which receives data from all site processors. The pattern match filter includes using previously recorded leak profiles. At site processes located at multiple points along a pipeline, a series of previously recorded signature leak profiles are continuously compared in real time against pipeline pressure signals. Data from each site processor are used collectively at a node processor and compared against multiple leak profiles to provide further false alarm rejection. The leak event data generated at each site processor is used by the node processor to declare a leak. By the application of this pattern match filter technique, the signal to noise ratio (S/N ratio) required to identify a leak event is reduced and the sensitivity of leak detection is increased.