薄互层等效各向异性的研究现状与存在问题

在长波长假设下,薄互层是一种典型的横向各向同性介质;长波长各向异性假设使得薄互层复杂结构反演成为可能.通过综述长波长假设下薄互层等效各向异性的理论发展、数值模拟和物理实验,发现该理论的适用条件较为严苛:对于韵律型薄互层,波长与互层单元厚度的比值需大于等于10;对于随机型薄互层,需满足等效的平均长度远大于单层厚度,且远小...

A state of the art on the equivalent anisotropy of thin interbeds

In seismic exploration,interbed deposits occur as thin layered or interbed formations which are typically described as anisotropic media or transverse isotropic media at long wavelengths.Based on a review of theoretical developments,numerical simulations,and physical experiments,it was found that very strict conditions need to be met to evaluate an equivalent anisotropy.In particular,for a rhythmic thin interbed,the ratio of the wavelength to the thickness of the interbed needs to be at least ten.For a stochastic thin interbed,the average length needs to be much larger than the thickness of the individual layers and much smaller than the main wavelength.Additionally,it was found that the equivalent anisotropy of a rhythmic thin interbed is closely related to the ratio of the wavelength to the thickness of the interbedded unit or layer,but also to the difference in physical property of thin reservoir.Finally,to evaluate an equivalent anisotropy for a stochastic thin interbed,the relationships among the average length,inhomogeneity scale,and main wavelength need to be accounted for.