Modeling and analysis of azimuthal AVO responses from a viscoelastic anisotropic reflector  

粘弹各向异性反射体模型方位地震AVO模拟及分析（英文）

作　　者：郭智奇[1] 刘喜武[2] 符伟[1] 李向阳[3,4] 

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026 [2]中国石油化工股份有限公司石油勘探开发研究院,北京100083 [3]中国石油大学(北京)油气资源与探测国家重点实验室,北京1022493 [4]中国石油大学(北京)CNPC物探重点实验室,北京102249

出　　处：《Applied Geophysics》2015年第3期441-452,470,共13页应用地球物理（英文版）

基　　金：sponsored by the National Natural Science Foundation of China(under Grant Nos.41404090 and U1262208

摘　　要：We propose a method for mOdeling azimuthal AVO responses from a fractured i reflector. The method calculates the integrated reflected wavetrains, and the wavetrains contain elastodynamic information including the contrast in impedance and anelasticity i across interfaces, the intemal anisotropic propagation, the dispersion and attenuation along i the wave path, and tuning and interference. The results suggest that for large angles of incidence, the velocity dispersion and attenuation increase the amplitudes of PP waves from the top and decrease those from the bottom. For azimuthal responses at specific angles of incidence, the reflected wavetrains of PP waves tend to have longer duration with increasing azimuth. In contrast, model-converted PSV and PSH reflections show stable azimuthal features and are less affected by the reflector thickness. The amplitudes of PSV reflections increase with increasing azimuth; moreover, the waves have no reflection energy at 0° and 90° azimuth and maximum amplitude at 45° azimuth.基于岩石物理模型和广义各向异性Zoeppritz方法在频率域计算裂缝型反射体模型反射波方位地震AVO响应。反射体模型为粘弹各向异性、有限厚度的地质体,其地震反射波形序列包含如下动力学信息,即分界面处介质的波阻抗和非弹性差异、反射体内部波的各向异性传播、在传播路径上的频散与衰减,以及来自顶底界面的反射波的调谐与干涉等。计算表明,速度频散和衰减增顶界面反射波大入射角反射时的振幅,而减弱底界面反射振幅。对于固定入射角的方位地震方位地震响应,PP波反射特征表现为随方位角的增加反射波形序列延续时间变长,而PSV和PSH转换类型反射波的方位各向异性变化特征稳定且受储层厚度影响较小,表现为PSV波反射振幅随方位角增加而增加,PSH波在0°和90°方位无反射能量,在45°方位反射振幅最强。

关 键 词：REFLECTOR viscoelastic and anisotropic dispersion and attenuation generalized anisotropic Zoelopritz theory azimuthal AVO 

分 类 号：P631.4[天文地球—地质矿产勘探]