Leak location in single pipelines using transient reflections

Abstract

The use of controlled, small amplitude transient (water hammer) signals for the detection of leaks in pipeline systems is a promising area of research. A pressure transient travels along the system at high speed and is modified by the system during its travel. Leaks within a pipeline partially reflect these pressure signals and allow for the accurate location of a leak by tracing the reflection to its source – a technique commonly known as time domain reflectometry. This paper discusses and provides possible solutions to a number of practical issues associated with leak detection methods of this type, including the impact of the system configuration and methods for detecting leak reflected signals within a transient trace. A set of equations has been derived to locate leaks in a pipeline for all locations of the transient source and measurement stations, and is essential for an automated monitoring system that uses more than one simultaneous measurement of the transient signal. A change detection algorithm is used in this paper to provide an automated approach for detecting leak reflections, which can reduce the ambiguity associated with simple visual inspection of the transient trace. This procedure was validated by both operational and offline (pipeline shutdown) experimental tests conducted at the University of Adelaide.