叠前信噪相干分离法及其应用

Prestak signal-noise coherent separation method and its application,

为获得用于地层岩性及储集层研究的高信噪比地震剖面,文中采用动校正后的CDP道集记录,经过时空平滑,利用信号的横向相关性和噪声的随机性,使其信号和噪声分离。为提高信噪相干分离效果,还揉合了CDP道集记录相加和CDP道集记录共炮检距相干拾取、随机重排及沿倾斜层信噪相干分离等辅助方法,以增加去噪能力。文中提供的地震剖面实例表明,该方法去噪能力较强,可提高水平叠加剖面的信噪比(约为原信噪比的1.4～1.5倍);而且,反射波的连续性好、中断点清晰,有利于地层岩性及储集层的研究。

In order to obtain high S/N seismic sections which favour the analysis of formation Hthclogy and reservoir, we may use signal lateral-correlation and noise randomness to separate seismic signals from noises in CDP gathers that have undergone NMO correction followed by smoothing in time-space dcmain. In addition, some auxiliary methods, such as addition, common-offset conerent pickup, random rearrangement and dipping interface signal-noise coherent separation of CDP gathers, are also used to enhance the effectiveness of signal-noise coherent separation. The seismic sections in this article prove that this method has high ability to remove noise,and improves signal-noise ratio (1.4～1.5 times as high as original S/N) of horizontal stack section. Furthermore, reflection events show good continuity and clear fault points, thus favouring the analysis of formation lithology and reservoir.