基于时频分析的地层吸收补偿

Stratigraphic absorption compensation based on time-frequency analysis

本文在分析地震反射波勘探信号时频分布特性的基础上提出了基于短时傅里叶变换的地层吸收补偿方法。首先用短时傅里叶变换对地震勘探信号进行分频；然后根据地层吸收特点在每一个频率上分别提取每一个时间点的吸收因子，并用其道数加权每一个短时傅里叶变换系数；再用加权后的短时傅里叶变换数重构地震反射波记录消除地层吸收。该方法不需要知道Q值，对变Q和常Q都能适应。实际应用效果表明，该方法能很好地补偿地层的吸收。

Stratigraphic absorption compensation based on short-time Fourier transform has been developed by analysing the time-frequency distribution characteristics of seismic reflection signals. The method has the following steps:Frequency dlvision of seismic signals is made by doing short-time Fourier transform.Absorption factor of every time is obtained at each frequency according to stratigraphic absorption characteristic, ahd each short-time Fourier transform coefficient is weighted by using the trace number.With the use of the weighted short-time Fourier transform coefficient, reflection seismogram is reconstructed to eliminate stratigraphic absorption.The method does not involve Q parameter, that is to say, it applies to both varying and constant Q values. Application result shows that the method compensates stratigraphic absorption satisfactorily.