信噪比的估算及其在高分辨率处理中的应用

The estimation of signal-to-noise ratio and its use in high-resolution processing

石油大学勘探系, 东营 257062

Department of Exploration,University of Petroleum,Dongying 257062

野外实际地震记录中总是包含有噪音的, 在进行高分辨率处理之前, 需首先了解这些噪音的强度及其频谱分布范围, 同时也要了解信号的强度和其频谱分布范围, 找出有效颇带的范围（即信噪比大于1的范围）。然后利用自适应频率加强和谐白化的方法提高分辨率, 在有井资料的情况下, 再利用测井资料所得的反射系数频谱作为约束对地震资料进行“监色谱校正”处理, 以进一步提高分辨率。这种方法在提高分辨率的同时并不降低其信噪比, 因为它对信噪比小于1的频带不予处理甚至进行了压制。实际资料的处理结果表明, 该方法简单, 是一种十分实用的高分辨率处理方法。

The actual field seismic data always contain noises. The intensity and the spectrumdistribution of the noises shou1d be found out before the high-resolution processing. Meantime,the intensity and the spectrum distribution of the signals shou1d also be found out in order to findthe range of effective frequency band. Then the adaptive frequency enhancement and spectrumwhitening methods are used to improve the resolution. When well log data are available, the "bluespectrum correction" processing of seismic data are performed using the refleCtivity spectrumobtained from well log data as the constraint so as to further improve the resolution. The methoddo not reduce the signal-to-noise ratio while improving the resolution, for it suppresses thefrequency band in which the signal-to-noise ratio is less than l. The actua1 data processing resultshows that the method is simple and very practica1.