地震波频散效应与反Q滤波相位补偿

Seismic wave dispersion effects and inverse Q-filter phase compensation

本文以Futterman提出的地震波振幅衰减和相速度频散表达式为基础,从井震匹配的角度出发,推导了不进行反Q滤波、仅反Q滤波振幅补偿、仅反Q滤波相位补偿,以及反Q滤波相位与振幅同时补偿四种情况下,地震波速度频散与相速度及地震记录振幅谱间的表达式,并从理论上说明了反Q滤波相位补偿的必要性.通过相同观测系统,炸药震源和可控震源分别激发采集的零偏移距VSP资料实例,验证了本文所推导的速度频散表达式的合理性;通过井震标定实例,进一步说明了反Q滤波相位补偿,可有效消除地震子波速度频散,提升地面地震资料与零偏移距VSP走廊叠加剖面的匹配度,最终提高地震资料成果的可信度.

Basing on the expression of amplitude attenuation and phase velocity dispersion proposed by Futterman, and considering the well-seismic matching, we derived the expression of seismic wave velocity dispersion between phase velocity and amplitude spectrum for the following four cases, without inverse Q-filter; with only inverse Q-filter amplitude compensation, with only inverse Q-filter phase compensation, with inverse Q-filter phase and amplitude compensation, and explained the necessity of inverse Q-filter phase compensation in theory. Through the zero-offset VSP data example of dynamite and vibroseis source with the same acquisition geometry, we verified the velocity dispersion expression derived in this paper. Through the example of wellseismic calibration, we further illustrated that inverse Q-filter phase compensation can effectively eliminate seismic wave velocity dispersion, enhance well-seismic matching, finally improve the reliability of surface seismic data.