用菲涅尔理论解释反射地质体边界的理论模型研究

A STUDY OF THE THEORETICAL MODEL FOR INTERPRETATION OF REFLECTED GEOLOGICAL BODY BOUNDARY USING THE FRESNEL’S LAW

煤炭工业部地球物理勘探公司

本文从地表地震测量和垂直地震剖面(VSP)的观测系统出发,从理论上分析了反射界面上菲涅尔带分布的特点及其对地震波振幅的影响,并由物理地震模型试验资料,证实了各种观测方式及反射地质体处于不同埋置条件下菲涅尔带半径的可测性,由此总结出用反射能量极大点—半幅点间距来估算第一级菲涅尔带半径的方法,验证了半幅点方法确定反射地质体边界的可靠性,为地震资料解释提供了理论及方法依据。

In the light of surface seismic survey and VSP layout, the distributional characteristics of Fresnel’s zone on reflector and its effect on seismic amplitude are examined. Also, all the observation modes as well as the radius’ measurability of Fresnel’s zone with the reflection geological body in different buried conditions have been proven through the seismic physical modelling data. As a result, an approach to estimate the radius of the 1 st Fresnel’s zone using the spacing interval of maximum point-half amplitude point of reflection energy is derived. And the reliability of determining the boundary of reflection geophysical body by means of the half amplitude scheme has been verified, so that it provides the theoretical and methodological basis for seismic data interpretation.