横向各向同性介质中弹性波的物理模拟

陆相薄到层沉积在一定程度上可以用横向各向同性（ＴＩ）介质来描述，通过对一种ＴＩ介质的地震物理模拟实验，给出了该介质模型不同观测方式的实验记录，并对介质中的波场，体波速度以及反射波的时差进行了分析，发现ＴＩ介质中的波场较各向同性介质中的波场要复杂得多，三种波体在介质中的传播速度随角度的变化也不同，在不同炮检距下，ｑＳＨ反射波具有相同的瞬时时差速度，而ｑＰ和ｑＳＶ反射波的瞬时时差速度却随炮检距的不同而

Physical modeling of elastic waves in transversely isotropic medium

Landfacies thin bed sediments can be simulated to some extent with transversely isotropic (TI) media. In this paper we give experimental records of a TI medium under different observation pat-tems by means of seismic physical modeling experiments on this medium model. After an analysis of wavefield, body wave velocity and reflection wave moveout in the medium, it is found that the wavefield in TI medium is much more complicated than in isotropic medium and that the propagation velocity variations of these three kinds of body waves with angle are different. When the offset changes, qSH reflected waves have the same instantaneous moveut velocity, but the instantaneous moveout velocities of qP and qSV reflected waves change with the offset. Under the circumstance of small offset, a unified moveout velocity can be used for approximation, which has nothing to do with the vertical velocity in the medium.