应用小波变换提高浅层地震记录分辨率

Application of wavelet transformation in resolution of shallow seismic record

地震资料分辨率较低主要是由于大地的滤波作用而导致地震波的高频成分衰减快,地震波的优势频率向低频方向移动.应用二进小波变换对地震记录进行多尺度小波分解,地震记录分解成多个频带,根据已知的地质先验信息,选取最能反映目的层的尺度,并对该尺度下的高频分量作补偿,即补偿因大地滤波作用而造成的高频分量的能量损失.模型及实际算例结果表明在保证信噪比的前提下,可使地震记录的分辨率得到明显提高.

The lowerresolution of seismic data is mainly owing to the effect of earth filtering, which leads to rapid decay of the high frequency component and makes the preponderant frequency of seismic wave drift toward lowfrequency. Using the dyadic wavelet transformation, the seismic record can be divided into several frequency bands on the multiscale. Then according to the known geological information, selecting the scale can reflect the object layer well and compensating for the high frequency component in the scale to compensate for the energy loss because of the influence of earth filtering. It is possible to improve the record resolution distinctly on the premise of high signal to noise ratio. The feasibility of the method is demonstrated by several models and field examples.