Study on the Distributed Optical Fiber Pipeline Leakage Prewarning System and the Method of Signal Analysis

A new distributed optical fiber pipeline leakage pre-warning system based on the principle of Mach-Zehnder optical fiber interferometer and the method of its signal analysis are proposed in this paper. In this pre-warning system, an optical cable is laid in parallel with the pipeline in the same ditch and three single mode optical fibers in the optical cable build up the distributed micro-vibrant measuring sensor. Leakage and other abnormal events can be detected by the sensor in real-time and can be identified by using an “energy-pattern” method based on the wavelet packet analysis. The position of the leak point can be obtained by calculating the value of time delay of the two measuring signals through a correlation algorithm. This system detects various oil and gas pipeline leakages, and is especially suited for micro-leakage. At the end of this paper, experimental data obtained on oil field and the result of the signal analysis are presented. The data and the result of the signal analysis show that the measuring sensitivity and location precision of detecting leakage are improved when this technology is adopted, and abnormal events can be efficiently identified.