考虑振幅随炮检距变化的人工合成地震记录制作方法

A method for making synthetic seismogram by considering amplitude versus offset (AVO).

利用褶积模型制作人工合成地震记录 ,进而标定层位是地震资料解释的基础工作。常规的反射系数递推公式建立在地震波垂直入射的基础上 ,这种递推关系因为没有考虑反射系数随入射角或炮检距的变化 ,所以得到的反射系数的数值大小与极性可能与实际资料相差较大 ,用于地震解释则容易造成岩性解释和层位标定的错误。本文通过对 Zoeppritz方程的简化 ,给出了非零炮检距条件下的反射系数递推公式。利用递推公式可以计算不同炮检距或不同道集的反射系数序列 ,与子波褶积后就可以得到较为准确的人工合成地震记录。模型试算证明了方法的准确性。

It is basic work for seismic data interpretation by using convolution model for making synthetic seismogram and then marking event. Building on the basis of vertical incident seismic wave by ordinary recurrence formula of reflection coefficients and having not considered variation of reflection coefficients with incident angle (or offset) by the recurrence formula, resulted quantity and polarity of reflection coefficients may have much difference with real data and easily resulted in errors in lithologic interpretation and event marking. The paper gave the recurrence formula of reflection coefficients in a non zero offset condition by simplified Zoeppritz functions. Using recurrence formula can calculate the reflection coefficient sequence at different offset and on different gather and convolution of the resulted section with wavelet can obtain more accurate seismogram. Model test shows correctness of the method.