A simulation of gas pipeline leakage monitoring based on distributed acoustic sensing

Abstract

A simulation test on gas pipeline leakage by using distributed acoustic sensing technology was designed. An optical sensing cable with a spiral structure was adopted to improve the sensitivity of leakage monitoring. The method of pipeline leakage signal identification and location based on fast Fourier transform is proposed. By analyzing the vibration of the optical fiber in the time and frequency domains, the leakage signal can be accurately monitored. According to the variation in the spectral average amplitude of each sensing channel, the leakage point can be located, and the positioning equation is given. The size of the leakage hole and the direction of leakage on the spectral characteristics of the leakage signal are discussed. The average absolute amplitude in the time domain and spectral average amplitude in the frequency domain of the leakage signal decrease with the size of the leakage hole. As the angle between the leakage direction and the direction from the pipeline to the optical sensing cable increases, the spectral average amplitude of the leakage signal gradually decreases. The effect of the distance from the leakage hole on the leakage signal is discussed. The average absolute amplitude of the leakage signal decreases with the relative distance between the leakage hole and the optical sensing cable.