Abstract:

The volatile nature of natural gas makes it extremely important to ensure that transport and distribution pipelines remain free from defects, as leakage can result in explosions. Current methods for testing buried pipelines rely on periodic excavation of a section of pipe and attachment of large acoustic or magnetorestrictive sensors. These systems, while reliable, suffer from a high cost‐per‐test ratio. To reduce the power requirements, we consider ultrasound embedded devices that could monitor the pipelines continuously. The problem with ultrasound is that, with buried pipes, the propagation is highly dispersive. We propose to use time reversal (TR), a signal processing technique, to refocus the signals and use, to our advantage, the dispersive nature of the environment. This paper will focus on the modes generated by various acoustic probing signals and the echoes received with and without TR. We argue that TR will be most beneficial when there are several dispersive modes present, a scenario avoided in conventional techniques. We will present simulation results for the detection of faults in a pipeline using PZFlex.