深度域保真与高分辨期望成像子波OA北大核心CSTPCD

The concept of seismic resolution has very important guiding significance in seismic data acquisition,seismic imaging and seismic geological interpretation.The description method of seismic resolution using dominant frequency,dominant frequency band and even octave of seismic wavelet is insufficient for seismic exploration targeting lithologic reservoirs at present and in the future;so it is necessary to give new connotation to seismic resolution.According to the theory of seismic inversion imaging,the resolution of imaging results is determined by the Hessian operator,which is also called point spread function(PSF),or imaging wavelet,in imaging analysis.The factors that determine the Hessian operator(or imaging wavelet)include source wavelet and wavelet at re-ceiver point,acquisition aperture(wide azimuth and long offset),migration velocity field and migration operator.For the imaging wavelet itself,its complete amplitude spectrum determines its resolution.This article starts with the definition of imaging resolu-tion and discusses the connotation and influencing factors of seismic resolution.Seismic resolving power comes down to the resol-ving power of the imaging wavelet.Further analysis suggests that imaging wavelets with broadband amplitude spectra dominated by low to medium frequencies exhibit stronger resolving power.Based on the physical interpretation of depth-domain fidelity and high-resolution imaging wavelet,as well as the requirements for true resolution at a target layer,we propose the concept of expec-ted imaging wavelet,based on which fidelity resolution is defined to be the main-lobe amplitude of a reflection wavelet from an ad-jacent formation.Fidelity resolution is a necessary condition for high-precision broadband elastic parameter(broadband wave im-pedance)reconstruction.The above new concepts related to imaging resolution have a clearer guiding significance for the acquisi-tion,imaging and geological interpretation of seismic data in the new era represented by seismic data acquisition with wide azi-muth,wide frequency band,high density and high signal-to-noise ratio and FWI inversion.