Leak detection in pipelines by frequency response method

TLDR

In the system frequency response, a leak increases the amplitude of pressure oscillations at the even harmonics. A new technique for detecting pipeline leaks using frequency response is presented. The method uses the oscillatory amplitude pattern of pressure oscillations to predict leak location and discharge, and discusses practical field implementation issues and limitations. The technique, requiring only a single location’s pressure transient history, accurately locates leaks with discharges as low as 0.2% of steady flow and is validated against the method of characteristics, offering advantages over existing methods.

Abstract

A new technique for the detection of leaks in a pipeline is presented utilizing its frequency response. In the system frequency response, a leak increases the amplitude of pressure oscillations at the even harmonics. Such an increase in amplitude has an oscillatory pattern; the frequency and amplitude of this pattern may be utilized to predict the location and discharge of a leak. In this technique, the pressure transient history at one location is sufficient and the history of the transient in the pipe prior to leak is not needed; this makes it advantageous over a number of other existing techniques, in addition to being simpler to use. It is shown that the technique successfully detects the location of a leak in a number of simple systems with leak discharge as low as 0.2% of the steady discharge. The technique is verified by comparing the results with those computed by using the method of characteristics. Practical issues and limitations for field implementations are discussed.