Comparison of Time Delay Estimation Methods Used for Fast Pipeline Leak Localization in High-Noise Environment

Pipeline networks are one of the most efficient and extensively used means for transporting fluid products. However, they suffer from a serious problem that threatens their normal and secure operation, which is the occurrence of leaks. In this article, an acoustic technique for the localization of leaks in pipelines placed in the high-noise environment of an oil refinery is described. This technique is based on the estimation of the time delay between the moments at which an acoustic signal produced by a leak reaches two sensors mounted on the external surface of the pipeline at a certain distance between them. For this reason, three different time delay estimation methods, based on the cross-correlation procedure, are studied in this article. These methods are tested for their accuracy in the estimation of the leak position, as well as for their ability to work with measurements of short duration and the results are compared. This is important because the acquisition duration affects directly the response time of the leak localization system, which is a crucial parameter for the targeted applications. Finally, an algorithm for fast and accurate identification of the leak point is proposed.