Frequency Domain Analysis for Detecting Pipeline Leaks

TLDR

The paper proposes leak detection techniques that inject a fluid transient into a pipeline and analyze the resulting frequency response to locate leaks. The authors develop two frequency‑domain methods: an inverse‑resonance approach that matches modeled and measured responses to estimate leak parameters, and a peak‑sequencing technique that locates leaks by comparing peak magnitudes, with additional procedures for extracting the linear frequency response, selecting optimal measurement points, accounting for unsteady friction, and extending the method to pipeline networks. A unique peak pattern in the frequency response identifies each leak location, and matching observed patterns to a numerically generated lookup table allows accurate leak localization.

Abstract

This paper introduces leak detection methods that involve the injection of a fluid transient into the pipeline, with the resultant transient trace analyzed in the frequency domain. Two methods of leak detection using the frequency response of the pipeline are proposed. The inverse resonance method involves matching the modeled frequency responses to those observed to determine the leak parameters. The peak-sequencing method determines the region in which the leak is located by comparing the relative sizes between peaks in the frequency response diagram. It was found that a unique pattern was induced on the peaks of the frequency response for each specific location of the leak within the pipeline. The leak location can be determined by matching the observed pattern to patterns generated numerically within a lookup table. The procedure for extracting the linear frequency response diagram, including the optimum measurement position, the effect of unsteady friction, and the way in which the technique can be extended into pipeline networks, are also discussed within the paper.