利用VSP和跨孔走时反演横向各向同性介质中的弹性常数

横向各向同性介质是地下各向异性介质的最常见形式，它可由五个弹性常数来描述。在这种介质中，其对称轴和垂直对称轴附近的慢度面近似为椭圆面。根据这个特点，我们提出了用ＶＳＰ和跨孔走时联合反演横向各赂异性的弹性常数，且不同求妥线性代文方法，可估计多层ＴＩ介质中任意各向异性的弹性常数，且不用求解线性代数方程组，也不用计算准ＳＶ波的正常时差速度。

Deriving the elastic constants of transversal isotropic medium from VSP and crosshole travel times

Transversal isotropic medium is the most typical one of subsurface anisotropic media,and it can be described with 5 elastic constants. The slowness surface near symmetric axes in the medium approximates to an elliptic surface. On the basis of this characteristic, we put forward a new method for deriving elastic constants of transversal isotropic medium from VSP and crosshole travel times. The method can be used to estimate any anisotropic elastic constants of multilayer transversal isotropic medium,without both solving for any linear algebraic equation system and computing NMO velocity of quasi SV-wave. It is shown that correct NMO velocity of quasi SV-wave often can not be obtained in strong anisotropic medium. Theoretical result says that the method is very adaptable and accurate.