地震波与地层共振匹配的探讨与应用

Discussion and application between seismic wave and layer resonance matching

在地震资料采集、处理中,低信噪比资料和深部地震信号的信噪比提升非常困难,提高信噪比是该类地震资料处理中最关键的一环,是决定最终成像品质的关键。针对该问题,首先从地震波在粘弹性介质中的传播规律出发,详细分析了粘弹性介质对其内部传播地震波的频率、能量和信噪比的影响,总结了地震波在经过地下粘弹介质传播后频率、能量和信噪比的衰减规律和低信噪比地震资料的频率、能量特点;然后讨论了地震波与地下岩层的谐振,并分析了它们之间的谐振与地震资料频带、能量之间的关系,提出了通过改造地震记录频率使之与地下岩层共振频率带匹配来改善地震资料成像品质的观点;最后讨论宽带Ricker子波的原理及其优点,提出应用宽带Ricker子波对地震记录进行子波整形,最终实现地震资料与地层响应频率的匹配,从而提高地震资料信噪比的具体应用方法。该方法已在多个区域的地震资料处理中应用中,并取得了良好的应用效果。这表明,通过地震资料与地层响应频率匹配的方法,可有效地提高低信噪比地震资料的信噪比,为低信噪比地震资料的处理提供了一条具有参考意义的思路。

It is very difficult to improve which the signal-noise ratio of the seismic data with either low signal-noise ratio（SNR）or the deep depth.To improve the SNR of eismic data is a key issue in seismic data process.For this problem,we first analyze the change of frequency,energy and signal-noise ratio of seismic wave which seismic wave spread in viscoelastic medium in this paper.The affect to the SNR of the seismic data from the relationship between seismic wave and layer resonance is analyzed.We then suggest that seismic data is reformed to matching layer＇s resonance frequency.The principle and advantages of wide-band Ricker wavelet is finally studied,suggesting that wide-band Ricker wavelet reform seismic data is used to matching layer＇s resonance frequency.The method has been applied to the seismic data processing in many regions,and good results have been achieved.This shows that the method of matching the seismic data and the formation response frequency can effectively improve the SNR of seismic data with low SNR,which provides a reference for the processing of low signal-noise ratio seismic data.