Abstract: Signal leakage detection of oil and gas pipelines is easily affected by noise, so de-noising becomes the key point. In order to improve the de-noising effect of oil and gas pipeline signals, a combined de-noising method based on savitzky-Golay smoothing filter, variational mode decomposition and frequency domain singular value de-noising method is proposed. Firstly, savitzky-Golay smoothing filter is used to reduce the noise of the leakage
signal in the time domain to remove the sharp pulse, high-frequency components and other noises and to improve the signal-to-noise ratio of the input signal. By calculating the Intrinsic Mode components (IMF: Intrinsic Mode Function) and the Manhattan distance between signals, distinguishing the signal components and noise, the noise component frequency-domain SVD (Singular Value De-noising), finally the filter components and signal are constructed. Simulation and practical experiments show that compared with single VMD method, VMD- wavelet transform and SG-VMD-SVD method, the signal to noise ratio is relatively higher, which verifies the superiority of de-noising effect and the feasibility of de-noising oil and gas pipeline leakage signal.

Key words: variational mode decomposition, savitzky-golay smooth filter, singular value decomposition in frequency domain, leakage signal