平面波反射系数与AVO技术

REFLECTION COEFFICIENT OF PLANAR WAVE AND AVO TECHNIQUE

1. 同济大学;2. 地质矿产部第一海洋地质调查大队

1. Tongji University;2. The First Party of Marine Geologic Survey, MGMR

本文讨论了声学介质与弹性介质在单界面和多层介质情况下平面波反射系数的实质。针对不同类型单界面,计算了相应的反射系数随入射角变化的曲线,分析了泊松比、速度和密度对反射系数曲线的影响。文中推导的固体多层介质情况下计算反射系数的公式及据此编制的反射波正演计算程序对于薄层AVO异常的解释是有意义的。最后,我们探讨了影响AVO曲线的各种因素,得到相应的结论。

This paper deals with the essence of the reflection coefficient of planar wave in terms of acoustic and elastic media in the single-boundary and multilayered medium. Aiming at the diversified single-boundaries,their respective curves of the reflection coefficients varying with incident angle are traced out. And the effect of Poisson's ratio,velocity and density on the reflection coefficient curve is examined. It is of interest for interpreting the thin-bedded AVO anomaly to calculate the equation of reflection coefficient in the solid multilayered medium as derived in the paper and based on which to write the reflection forward computation program. Finally,the different factors that may affect the AVO curve building-up are discussed. A tenable conclusion is drawn.