Amplitude-variation-with-offset, elastic-impedence, and wave-equation synthetics — A modeling study
Amplitude-variation-with-offset, elastic-impedence, and wave-equation synthetics — A modeling study
复制标题
DOI：
10.1190/1.2387108
复制
发表时间：
2007
期刊：
影响因子：
3.3
通讯作者：
S. Mallick
中科院分区：
文献类型：
--
作者：
S. Mallick
振幅随炮检距变化（AVO）和弹性阻抗（EI）分析使用近似的平面P波反射系数作为入射角的函数。AVO和EI都可以用于三项或两项公式。本研究使用合成数据来证明，在大的偏移距的P波的一次反射可以被其他波模式的反射，可以影响三项AVO或EI结果的质量污染。地震波在精细分层介质中传播时，P波和S波的耦合会产生干扰波模式。一种方法，如叠前波动方程模拟可以适当地考虑这些耦合效应。AVO和EI都采用卷积模型，其精度随着入射角的增加而降低。另一方面，波动方程建模基于波动方程的严格解，并且对任何入射角都有效。由于在小角度时波的干扰最小，因此可以采用两项AVO/EI分析来限制地震波的传播。
Amplitude-variation-with-offset (AVO) and elastic-impedance (EI) analysis use an approximate plane P-wave reflection coefficient as a function of angle of incidence. AVO and EI both can be used in a three-term or a two-term formulation. This study uses synthetic data to demonstrate that the P-wave primary reflections at large offsets can be contaminated by reflections from other wave modes that can affect the quality of three-term AVO or EI results. The coupling of P-waves and S-waves in seismic-wave propagation through finely layered media generates the interfering wave modes. A methodology such as prestack-wave-equation modeling can properly account for these coupling effects. Both AVO and EI also assume a convolutional model whose accuracy decreases as incidence angles increase. On the other hand, wave-equation modeling is based on the rigorous solution to the wave equation and is valid for any incidence angle. Because wave interference is minimal at small angles, a two-term AVO/EI analysis that restri...