小波变换在波阻抗反演中的应用

根据国内外广泛采用的波阻抗随机反演理论，提出了多道小波波阻抗反演方法，消除了噪音对反演结果的影响。针对地震剖面上不同频带和时段上有不同的信噪比，以及相邻地震道反射波有效成分在波形和能量上有较强的相关性特点，运用多道记录同时进行波阻抗反演，在迭代过程中将实际记录与模型合成记录的残差道进行小波分解，形成残差道分频小波剖面，然后利用Ｋ－Ｌ变换提取分频剖面中的相干部分用于波阻抗变化量的计算，从而避免了噪音参与波阻抗反演。展示了理论模型与实际应用的例子。

APPLICATION OF WAVELET TRANSFORM IN THE ACOUSTIC IMPEDANCE INVERSION

Based on the widely used theory of acoustic impedance, The authors of this paper present a inversion method for multi trace by wavelet transform, which can overcome noise effect from inversion results. According to different S/N for different frequency bands and different time intervals in a seismic section, and the fact that there are quite good correlation between the waveforms or energy of the effective waves of neighboring seismic traces, through the inversion of acoustic impedance by using multi trace record simultaneously, the residual error of signal and noise is decomposed by wavelet transform during the process of iteration, we can get seismic sections of residual error for different frequency, the coherent component extracted in seismic section by K-L transform is utilized in the computation of acoustic impedance modification and so noise can be removed while impedance inversion being performed. Theoretical model and practical examples are also presented. They show that this method has good stability and application potential.