Abstract:

At present, pipeline leak detection methods can effectively detect sudden leaks. While the leak signals caused by slow leak are relatively gentle and easily submerged in noise, there are problems such as low sensitivity and inaccurate location for slow leak detection. Based on this, a slow leak detection is proposed with signal enhancement. The shortcoming of the small pressure decline rate of slow leak can be overcome by compressing (drawing and shifting) the pressure signals. Based on the advantages of the sharp waveforms and sensitive to sudden leaks of acoustic signals, the acoustic signal transmitter model with pressure signal as input and virtual acoustic signal as output is established, which overcomes the shortcoming of the leak pressure signal being easily submerged in the pressure fluctuations and noise of the pipeline, and achieves the slow leak signal enhancement. And the virtual acoustic signal is reconstructed based on the adjacent interpolation method. Then accurate location is achieved by the cross-correlation of corresponding virtual acoustic signals. The results show that the method has significant signal enhancement and positioning accuracy, and achieves accurate detection of slow leakage.

Key words: slow leak, signal compression, virtual acoustic signal, signal enhancement, algorithm, petroleum, instrumentation

摘要：

目前管道泄漏检测方法可有效检测突发泄漏，对于缓慢泄漏则存在检测灵敏度低、定位不准确等问题。基于此，提出了一种基于信号增强的缓慢泄漏检测方法。通过信号压缩（抽取及移位）克服缓慢泄漏压力信号下降平缓的缺点；根据声波信号具有波形尖锐突出、对突发泄漏敏感的优点，通过建立以压力为输入、虚拟声波为输出的声波信号变送器模型，将压力信号转换为声波信号，克服了泄漏压力信号容易被淹没在管道压力波动及背景噪声中的缺点，实现了缓慢泄漏信号的增强；利用临近插值方法重构虚拟声波信号，基于延时互相关分析实现了缓慢泄漏的准确定位。实验结果表明，该方法具有显著的信号增强效果和定位精度，实现了缓慢泄漏的准确检测。

关键词: 缓慢泄漏, 信号压缩, 虚拟声波, 信号增强, 算法, 石油, 仪器