Dealing with stochastic signals and physical phenomena impacting pipeline leak localization accuracy

Leak localization in pipelines is a subject frequent in the literature, with most studies focusing either on the errors in the acquisition process, e.g. what types of sensors to use, or on the weak points of the signal processing methods utilized for this matter, how to deal with these vulnerabilities and improve the accuracy of those methods etc. However, another important factor that needs to be considered is the presence of several physical phenomena that take place in a pipeline and affect the creation and propagation of acoustic waves. Such phenomena like the acoustic dispersion, the frequency dependent attenuation and the resonances are studied in this paper, based on synthesized signals, and their influence on the leak localization accuracy is discussed. Furthermore, a leak localization method combining the cross-correlation technique with temporal and spectral segmentation of the acoustic signals is proposed. This method is applied to measured (stochastic) leak signals from a pipeline in a laboratory setup. Experimental results show that the proposed method can efficiently determine the position of a leak in a pipeline, since the localization error in most cases is below 3%.