各向异性介质P-SV转换波速度分析方法及应用

Converted-wave velocity analysis and its application in anisotropic media

由于地球介质中广泛存在各向异性,地震时距关系多表现为复杂的非双曲线形式。因此,基于双曲时距关系的速度分析方法不适用于各向异性介质转换波的速度分析。采用了由转换波资料直接进行速度分析和各向异性参数估计的方法,该方法应用分式展开时距方程及改进的相似系数能量准则,可简化处理过程、避免求取转换点、减少误差累积、提高速度分析精度。垦71地区实际资料的转换波速度分析处理表明了该方法的正确性。

The travel time curve of seismic wave is actually not a hyperbola. Velocity analysis based on hyperbolic travel time curve is therefore not sufficient for converted waves in anisotropic media. We used converted-wave data directly to analyze velocity and estimate anisotropic parameters. With the fraction expansion time-distance equation and improved semblance coefficients energy rule, the proposed method avoids calculating converted-points, which decreases error accumulation, simplifies process, and increases computational accuracy. Applications in Ken 71 area manifest the validity of the method.