弹性介质中非线性多散射地震成像与反演研究

项目名称： 弹性介质中非线性多散射地震成像与反演研究

项目编号： No.41474120

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 毛伟建

作者单位： 中国科学院测量与地球物理研究所

项目金额： 90万元

中文摘要： 在地震成像和反演的研究中，通常采用的方法都以线性单散射为假设条件。这些方法能够在一定程度上解释地震数据、重构介质模型。然而，从理论上讲它们只是适合于小扰动缓慢变化的介质模型，当在处理复杂地下介质的高精度、高分辨率成像和反演问题时它们却遇到了种种困难。其主要原因是快速变化的复杂地质结构产生非线性多散射效应。因此，人们正努力探索一些新方法用于求解与非线性多散射有关的多次波偏移，非线性作用模式的波场外推，保幅偏移等。在此申请项目中，我们将利用矢量弹性波动方程(各向同性，各向异性)建立散射场与弹性参数之间的非线性多散射关系(二阶Born近似，Born级数等)，尝试运用广义Radon 变换（GRT）、逆散射序列和微局部分析等数学方法探讨复杂弹性介质的地震成像和反演理论，并采用工业标准模型检测理论和数值算法的有效性。其研究目标是通过非线性反演直接获得在真振幅意义下的地震成像和弹性参数信息。

中文关键词： 地震成像；地震反演；非线性；弹性波；多散射

英文摘要： In seismic imaging and inversion，conventional methods are based on the assumption of linear single-scattering model.These methods can describe seismic data and reconstruct subsurface models to a certain extent.Theoretically,they are only suitable for the medium with small perturbation,there are many problems when they are used to handle the high accurate and high resolution imaging and inversion in an area with complex structures.The main reason is that the complex geological structure with rapid changes of the medium parameters produces nonlinear multiple-scattering effects.Therefore,in the oil and gas industry, one is working hard to investigate possible new methods, which can deal with the migration of multiples, wavefield extrapolation with nonlinear model interactions, amplitude-preserving migration and so on.In this study, we will establish the nonliner multiple-scattering relationships(e.g.,second-order Bornapproximation, Born series)between the scattered field and the elastic parametersby adopting vector alelastic wave equation (isotropy and anisotropy),investigate sesimic imaging and inversion in the complex elastic medium via mathematical methods(e.g., GRT, inverse scattering series and microlocal analysis), and test the effectiveness of the theory and numerical algorithms by using the benchmark models in the oil industry. The aim is to obtain seismic image and elastic parameters in the sense of true amplitude by nonlinear inversion methods.

英文关键词： seismic imaging;seismic inversion;nonlinear;elastic wave;multiple scattering