Converted-wave Velocity Analysis In Anisotropic Media: Method And Application

Velocity analysis plays an important role in the process of seismic data. Because of the widespread existence of anisotropy and the asymmetry of converted wave raypath,most of the traveling time curves of seismic waves still present as complicated non-hyperbolic curves. So the velocity analysis methods based on hyperbolic traveling time curves,assumed by isotropy, aren't suit for the converted-wave velocity analysis in anisotropic media any more. So, the theory of converted-wave velocity analysis in anisotropic media requires being studied further.This paper analyses the influence that the anisotropic effect makes to the velocity analysis and the relationship among anisotropic parameters,velocity traveling time curves, and application conditions of anisotropic parameters, and cites the high-order Taylor series expansion formula and the double square root(DSR)equation suitable. What's more, according to fraction expansion equation, then anisotropic parameters introduced by Li are substituted into the equation, and derives a fraction expansion two-order time-distance equation suitable to any anisotropic force. On the basis of appeared Taner spectra, this paper introduces the modified velocity analysis rules, which improves the resolution of velocity spectrum . Combined with above theories, this paper does much further research on analysis methods of converted-wave velocity analysis, gets more accurate analysis methods, and develops the interactive velocity analysis software. By using of these methods,velocity of P-wave and S-wave in anisotropic medium can be calculated,and the anisotropic parameters can be got. The process of theoretical model and real data has proved these methods accurate and advisable.