论文详情
多层地震物理模型的单炮记录中有一种特殊的干扰波，在埋深较浅的界面附近能量较强，在中、远偏移距上会与反射波同相轴交叉，严重影响了反射波的振幅分析。基于一个多层物理模型，在相同参数的数值模型上利用波动方程正演模拟分析这种干扰波的产生机理，并利用射线追踪方法对其传播路径进行追踪分析。结果显示这是一种经历了P-S-P多次转换过程的干扰波。分析认为，一般设计制作的多层物理模型中各层介质之间的相对波阻抗差异较大，入射纵波容易产生能量较强的透射横波，传播到下一界面时又会产生反射纵波传播上来，在浅层界面附近产生能量较强的干扰波。在地震物理模型实验数据的处理中，利用Radon滤波可以很好地去除这种多次转换干扰波。
One special interference wave frequently appears in the shot records of multi-layer seismic physical models,whose amplitude is relatively strong around the shallow interfaces.The interference wave intersects with the reflection wave events from middle and far offset and severely affects the amplitude analysis on reflection wave of seismic physical modeling data.Based on a multi-layer physical model,we use elastic wave equation forward numerical simulation to analyze the generation mechanism of the interference wave for a multi-layer numerical model with the same parameters.Then the ray tracing method is utilized to trace its propagation path and we find that it is a P-S-P multiple converted process.It was believed that the difference of the wave impedance between adjacent layers is relatively large in multi-layer physical modeling,therefore the incident P-wave can generate transmitted S-wave with stronger energy,and when the S-wave arrives at nearby interface it will induce reflected P-wave again.The amplitude of the interference wave is relatively large near shallow interfaces.In the processing of seismic physical modeling data the multiple-converted interference wave can be removed by Radon filtering.