Study On Seismic Frequency Expanding Technique Based On Acoustic Logging

In seismic exploration field, we combine seismic data with acoustic logging data for integrated research, in order to gain more detailed information of the reservoir. However, high resolved logging information is decreased to relative low resolved seismic information in processing. This paper puts forward seismic frequency expanding technique based on acoustic logging.We make broadband synthetic seismogram by convolution between high frequency seismic wavelet and reflection coefficient which is calculate from acoustic logging and density logging data. Comparing synthetic seismogram with through-well seismic traces, we can obtain the loss regularity of vertical frequency signal that is caused by low-pass filter of formation. Meanwhile, comparing near-well seismic traces with arbitrary CDP trace of the section, we can obtain the filtering effect about lateral variation of formation.Through studying the amplitude-spectral characteristic of the filter, we sum up lateral and vertical characteristic about stacked seismic data, design a tandem inverse filter which includes the loss of longitudinal frequency information and variation of transverse frequency and apply the filter to original stacked seismic sections. The frequency expending inverse filter is designed to widen the frequency bandwidth of stacked seismic data and improve its resolution. Comparing with actual cross-well logging data, the frequency expending method proves a good result.