Method Of Anisotropic Multi-wave Velocity Analysis

Velocity analysis acts as an important function in seismicexploration. However on the assumption that the layers are isotropic, it appears insufficiency when it needs higher precise exploration. Anisotropy makes it insufficiency to get the vertical velocity by the conventional hyperbolic approximation for short-spreads. The precise of velocity analysis is controlled by the approximation formulas of moveout curve and the analysis method. So when the layers have the anisotropic properties, seismic wave' s velocity and moveout will become complex. It needs to acquire the anisotropic moveout formulas and the connection of layers parameters with velocity. Then using multi-wave information sufficiently to analyse the seismic data.On the basis of literatures appeared, for the vertical transverse isotropy layers, firstly learn the hyperbolic approximation formula about the reflection moveout on short-spreads; secondly derivate the non-hyperbolic approximation formula about the reflection moveout on intermediate-spreads and long-spreads detailedly. Gain the high precise formula about P wave, S wave and Converted wave. At the same time get the connection of layer' s anisotropic parameters with moveout curve and velocity by the numbers. For adapting to the anisotropic analysis, need to derivate the convert-point formula. It studies the method of anisotropic velocity analysis about pressure wave, especially converted-wave. These methods can derive not only seismic wave' s velocities but also the anisotropic parameters. And it is proved to be valid by processing theoretical models.In this paper, the practical data is analysed and get a good effect. It proves that it is vailed for VTI layers using the approximation moveout formula in this paper. This method has a good foreground.