Study on leak localization for buried gas pipelines based on an acoustic method

Abstract

As an important part of a city’s “lifeline,” an urban underground natural gas pipeline network is an integral part of the infrastructure, facilitating energy transmission. If the source of a leak is not located accurately, explosive incidents may occur owing to the highly flammable nature of natural gas, causing casualties and property damage. Thus, this study presents a new method of leak identification in buried natural gas pipelines. The proposed method achieves this goal through leak noise in the soil, and this is verified through experiments conducted as part of this research. The surrounding soil of the buried pipeline was considered as the propagation medium of the noise associated with leaks. For four microphones, placed in detection holes, were used to capture leak noise within the soil. Multi-layer wavelet packet decomposition was performed on the collected time domain signal of leak noise and was reconstructed on the characteristic frequency band of 0–200 Hz. Leak localization was completed by estimating the time difference of arrival between each pair of microphones on the buried natural gas pipeline. In the experimental scenario, the leak location error of the buried gas pipeline was 8 %–12 %. Therefore, the proposed method can successfully be applied to realize leak localization for buried natural gas pipelines.