基于白化滤波的天然气集输管道微泄漏定位方法

Microleakage locating algorithm of gas gathering pipeline based on whitening filter

油气田集输管道因腐蚀导致的微泄漏信号提取和识别是泄漏监测技术领域的一大难题。针对淹没在管道噪声中的微弱泄漏信号,提出了一种基于白化滤波的天然气集输管道微泄漏定位方法。以某油田天然气集输管道为例,采用自适应白化滤波算法消采集信号中的除低频分量,进而对泄漏定位公式进行优化,通过互相关方法计算管道上、下游信号的延迟时间,得到泄漏点位置。结果表明:利用所提出的方法,白化滤波处理后的信号功率谱趋于平坦且接近白噪声,信噪比提高约4dB,可检测到管道中的微弱泄漏信号,泄漏点定位误差为2 m,建议进一步开展在不同介质、压力等级、地形条件管道中的示范应用,以期提升油气田集输管道的安全管理水平,助力无泄漏示范区建设。

The extraction and identification of microleakage signal caused by the corrosion of gathering pipelines in the oil and gas fields is a great technical challenge for leakage monitoring. Therefore, a microleakage locating algorithm of gas gathering pipeline based on whitening filter was proposed for the microleakage signal submerged in the pipeline.noise As the acquired signal of gathering pipeline contains an abundance of low-frequency components, tracking with the adaptive whitening filter can eliminate the low-frequency components, so that the power spectrum of the acquired signal becomes flat and close to the white noise. The microleakage signal processed by whitening filter is enhanced, and the signal-to-noise ratio(SNR) is increased by nearly 4 dB. At the same time, the cross-correlation operation with the signals processed by whitening filter can calculate the time delay of signals at both ends of pipline, futher locate the microleakage point of gathering pipeline by leakage positioning formula. According to the calculation results, the algorithm can accurately locate the microleakage signal of the oil and gas field gathering pipeline, with error of 2 m. Thus, demonstration application should be provided for various media at different pressure levels under different topographic conditions, so as to improve the locating accuracy of the algorithm, further providing technical support for the construction of no-leakage demonstration area.