论文部分内容阅读
在横向各向同性介质中波的传播受水平和垂直波速的控制。准P(qp)波波前不是椭圆的,因此,波的传播就不能用椭圆各向异性介质波动方程来描述。然而,对于与垂向呈有限夹角的范围而言,准P波的波散关系可用椭圆来近似。此近似所采用的水平速度不同于实际水平速度,它取决于介质的物理特性。在本文描述的方法中,地震数据用椭圆各向异性介质中45度角波动方程进行偏移采用的水平速度通过比较45度椭圆波散关系与准P波波散关系后确定。该方法已用合成数据集做了验证。
The propagation of waves in a transversely isotropic medium is governed by the horizontal and vertical wave velocities. Quasi-P (qp) wavefront is not elliptical, so wave propagation can not be described by elliptic anisotropy medium wave equation. However, for a range that is at a limited angle to the vertical, the quasi-P-wave dispersion can be approximated by an ellipse. The horizontal velocity used for this approximation differs from the actual horizontal velocity and depends on the physical properties of the medium. In the method described in this paper, the horizontal velocity of seismic data offset by 45 degree angle wave equation in elliptical anisotropic medium is determined by comparing the wave-length relationship of 45 degree elliptic wave with quasi-P wave. This method has been verified with a synthetic data set.