摘要
波动特征研究对各向异性介质的弹性参数反演,速度反演、NMO,DMO、时间域的偏移以及地震资料的精确解释有着重要意义.本文由Christoffel方程出发推导出二维VTI介质中XOZ对称平面内弹性波相速度与各向异性参数的关系式以及慢度面的计算式并通过理论模型分析得出以下结论:1)ε值决定了P波的水平相速度的大小,反映了P波水平传播的相速度与垂直传播的相速度的差异;δ值决定了P波垂直方向附近相速度的各向异性程度的大小.2)VTI各向异性介质中纵波偏振方向不再与慢度面是平行而是有一定的夹角,且SV波的慢度面不再完全与偏振方向垂直的.3)准SH波的波慢度面呈椭圆,准P波与准SV波慢度面为不规则椭圆.
The study of volatility characteristics is very significative for the inversion of elastic parameters, velocity, NMO, DMO, time migration and accurate interpret of seismic data. The relationship between phase velocity and Thmosen parameters is derived from Christoffel equation and calculation formula of the slowness is also derived. Through theoretical model analysis it is concluded that： 1） edetermines the velocity of horizontal P-wave and reflects the differences in phase velocity between the horizontal and vertical P-wave; δ determines the Anisotropic level of p-wave phase velocity in near the vertical direction. 2） In VTI media P-wave polarization direction is no longer parallel to the slow surface but in a certain angle, and SV wave slow surface is no longer completely vertical to the polarization direction. 3） The shape of slow surface of qSH wave is elliptical, the slow surface of qP and qSV wave is of irregular oval.
出处
《地球物理学进展》
CSCD
北大核心
2009年第4期1291-1298,共8页
Progress in Geophysics
基金
湖南省自然科学基金项目(05SK3077)资助
关键词
VTI
相速度
慢度
各向异性
VTI, Phase velocity, slowness, anisotropy
