Application of Wavelet Transform to Detect Leakage for Oil Pipeline

The oil pipeline accident occurs for many reasons. In order to reduce the loss which the accident creates, the leakage should be discovered promptly. This paper introduces the basic theory of applying negative wave to detect the leakage, and analyzes the characteristic of pressure signal singularity and the different characteristics between signals and noises based on their wavelet transforms. Namely the sudden change signal wavelet transformation mold maximum value increases along with the criterion increase, but the noise wavelet transformation mold maximum value decreases along with the criterion increase. Therefore, the leaking point position can be figured out by using the time difference and propagation velocity of the negative pressure wave, which may arrive at the oil pipeline beginnings and ends. The result of the example indicated that, the wavelet method of transformation can accurately withdraw the sudden change value of the transient negative pressure wave, thus the leakage location can be detected.