Pipeline Leak Detection Signal Processing Research

With the improvement of the oil strategically location in the world economy and society, more and more people pay attention to the convenient, fast, safe oil pipeline transport.Due to various natural and anthropogenic factors, such as corrosion, surface subsidence, urban construction, man-made drilling oil Stolen and other reasons, oil pipeline leakage occurred frequently. If the detection of leaking and the location of pipeline leakage is not found in time, would result in substantial waste of resources, and may be brewing a major safety and environmental pollution accidents. At present, the method based on leakage signal processing has been widely used in pipeline leak detection and location. With its cost-effective, simple, practical, high reliability and good positioning performance testing, negative pressure wave detection method is widely applied in the world.In this paper, due to the high false alarm rate shortcomings of the traditional single pressure sensor is hard to recognize the false negative pressure wave generated by condition of adjusting leakage pressure sensor, our group apply the dual pressure sensor to exclude false negative pressure wave. Due to the problems of time domain correlation analysis with complex interference noise is difficult to determine the direction of the pressure wave propagation accurately, our group apply the spectral phase difference analysis method to reliably determine the direction of the pressure wave propagation, rule out the false appearance and false alarm effectively.This paper design the signal data processing software and test the system with the actual daqing oil field pressure data.The test prove that the pressure sensor method combined with spectral phase difference analysis can solve the false alarm problem caused by real adjustment of complex conditions effectively. Research of thesis work are as follows:1.The thesis analysis the factors of pipeline fluid pressure wave in experimental data and the reasons of false appearance caused by negative pressure wave, provide a theoretical basis of pipeline leak detection for the complex interference environments, proving reliable method to reduce false alarm and exclude false appearance by example of dual pressure sensor.2. The article describe the basic principles of cross-correlation, spectral phase analysis method, because analysis of time series correlation function with the capacity of coherent structures, analysis the reason of time domain correlation method which sometimes determine the error propagation direction of pressure wave. Application of phase spectral analysis method can solve the identification problem of pressure wave propagation direction.3. This paper applicate the VC ++. NET to design dual pressure sensor negative pressure wave signal processing and analysis system and test with actual data.