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为了研究衰减和各向异性对反射系数的影响,我们分析了单色和黏弹性波入射到两种横向各向同性且有衰减介质之间的界面上的情况,而介质的对称轴垂直于界面。通过对PP和PS反射系数分析发现,在研究有关页岩的振幅随炮检距变化(AVO)时应当考虑各向异性。不同的各向异性特征可以使反射趋势发生反转,并极大地影响临界角对炮检距关系的位置。对页岩/白垩界面分析显示,当临界距离接近炮检距时,AVO响应由于存在损耗而受到极大影响。第二个例子中,我们计算了灰岩/黑色页岩界面的反射系数,并制作了合成地震记录,界面之下的页岩具有不同的流变特性,该情况表明反射趋势随炮检距增大发生反转,同时还表明各向异性和滞弹性作用间的补偿。
In order to study the effect of attenuation and anisotropy on the reflection coefficient, we analyze the monochromatic and viscoelastic waves incident on the interface between two transversely isotropic and decaying media, with the axis of symmetry of the medium perpendicular to the interface . By analyzing the reflection coefficients of PP and PS, it is found that anisotropy should be considered in studying the variation of shale amplitude with offset (AVO). Different anisotropy features can reverse the reflection trend and greatly affect the critical angle versus offset position. Analysis of the shale / chalk interface shows that when the critical distance approaches offset, the AVO response is greatly affected by the loss. In the second example, we calculated the reflection coefficient of the limestone / black shale interface and produced synthetic seismograms with different rheological properties of the shale beneath the interface, which shows that the reflection trend increases with offset Large reversal, but also shows the anisotropy and the role of anelastic compensation.