高分辨率层序地层学在川西地震资料反演中的应用

Application of high-resolution sequence stratigraphy in inversion of seismic data in western Sichuan

基于模型的方波化反演法具有明显的多解性 ,横向上的多解性不仅与约束井的数量及分布密度有关 ,还与地震层位框架模型有关。通常的模型框架是 ,在几个稀疏的主要目的反射层位间 ,以均匀充填地震参数的方式构成。运用高分辨层序地层学原理及研究方法 ,构建地震剖面的等时地层格架 ,建立高精度地震层位框架。理论模型和实际资料在 2种不同的地震层位框架模型下的反演结果说明 ,在约束井的数量及分布密度一定的情况下 ,用三维高分辨率层序地层划分结果 ,生成三维波阻抗反演中的地震层位框架模型 ,建立强地质约束 ,可以减少方波化反演的横向多解性 ,且可获得地质意义上的最优解。

The solution of model based blocky inversion is non-unique. The lateral non-uniqueness of the method is related to the number and distribution of wells as well as the stratigraphic framework model. The framework model usually consists sparsely of main seismic reflectors with seismic attributes evenly distributed between them. In this paper, we established a chronostratiphic framework and further a high-resolution seismic stratigraphic framework by using principles of high-resolution sequence stratigraphy. The inversion results, resulted from theoretical model and field data based on these two different seismic stratigraphic frameworks, showed that under fixed number and distribution of wells, lateral non-uniqueness can be reduced and optimum solution can be obtained gelogically by establishing a 3-D seismic stratigraphic framework for impedance inversion and imposing strong constraints during inversion.