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弹性波逆散射是非均匀介质参数反演的有效途径.本文从弹性波逆散射理论出发,利用微扰理论和稳相法,将非均匀介质参数视为背景介质与扰动介质参数的叠加,建立了纵波散射系数和非均匀介质中背景介质与扰动介质孔隙流体参数,剪切模量与密度间的直接关系.进而发展了一种非均匀介质孔隙流体参数叠前地震贝叶斯反演方法.该方法假设模型参数(扰动介质与背景介质孔隙流体参数,剪切模量与密度的比值)服从柯西分布,反演目标似然函数服从高斯分布,并采用平滑初始模型约束提高反演稳定性.模型和实际资料处理表明,该反演方法能够稳定合理的直接从叠前地震资料中获取孔隙流体参数,提供了一种高可靠性的非均匀介质流体描述方法.
The backscattering of elastic wave is an effective way to invert the inhomogeneous medium parameters.Based on the elastic wave inverse scattering theory, the perturbation theory and the stationary phase method are used to treat the inhomogeneous medium parameters as the superposition of the background medium and the disturbance medium parameters Longitudinal wave scattering coefficient and the relationship between background medium and pore fluid parameters, shear modulus and density in heterogeneous media, and then developed a prestack seismic Bayesian inversion method for inhomogeneous media pore fluid parameters. The method assumes that the model parameters (the ratio of pore fluid parameters, shear modulus and density of disturbing medium to background medium) obey Cauchy distribution, the objective likelihood function obeys Gaussian distribution, and uses the initial model to improve the inversion stability. The model and actual data processing show that the inversion method can obtain pore fluid parameters directly and stably from prestack seismic data, and provide a highly reliable inhomogeneous medium fluid description method.