粗糙界面地震反射波场的滤波特性  

Filtering characters of seismic reflection wavefield on coarse interface.

作　　者：孙成禹[1] 

机构地区：[1]石油大学(华东)地球资源与信息学院

出　　处：《石油地球物理勘探》2004年第1期24-28,共5页Oil Geophysical Prospecting

基　　金：山东省优秀青年科学家科研奖励基金资助

摘　　要：本文利用克希霍夫积分 ,推导了粗糙界面地震反射波场的表达式 ,从理论上研究了粗糙界面对地震反射波的滤波特性 ,并通过数值算例对此理论推导结果进行了验证。研究表明 ,在粗糙界面的起伏波长λr 与地震波波长λ相差不大的情况下 ,存在一个临界频率 fc。对于地震波波长小于 2λr 的地震波分量 (或大于临界频率 fc 的频率成分 ) ,在经过粗糙界面反射后将会产生较强的畸变 ,即对高频信号有较强的滤波作用 ;对于地震波波长大于 2λr 的地震波分量 (或小于临界频率 fc 的频率成分 ) ,其滤波作用一般可以忽略。该临界频率还与深度有关 ,深度越大 ,该频率越高 。Using Kirchhoff integration,the paper deduced the expression of seismic reflection wavefield on coarse interface,studied theoretically the filtering characters of seismic reflection on coarse interface and proved the theoretically induced results by numerical cases.The study showed that there exists a critical frequency f c on a condition that the difference between undulate wavelength of coarse interface λ r and seismic wavelength λ is very small,the seismic wave components that their wavelengths are less than 2λ r (or the frequency components are great than the critical frequency f c) will be strongly distorted after reflection on coarse interface,that is,having strong filtering action on high frequency signal; but the filtering action can be neglected for the seismic wave components that their wavelengths are great than 2λ r(or the frequency components are less than the critical frequency f c).This critical frequency is also related to depth,the deeper the depth is,the higher the frequency is and the weaker the filtering action of coarse interface on reflection wave is.

关 键 词：滤波 克希霍夫积分 地震反射波场 粗糙界面 地震波 反射系数 

分 类 号：P631.4[天文地球—地质矿产勘探]