VSP资料约束地层反滤波研究

A Study of VSP Data Constrained Stratigraphic Deconvolution

浅地表的低速带和地层滤波作用导致地震信号的能量衰减,地震子波的高频快速衰减,速度频散的子波变形,对地震底层分析带来了严重的影响。地层反滤波算法就是为了消除地层对子波的影响,利用VSP中的直达下行波推算出每个地层滤波算子,计算出各个地层滤波算子的反算子,然后利用这些反算子恢复出地表记录中损失掉的高频成分,减弱地层滤波对波形的影响,增加地表记录的频率成分和波形的准确度。分析实际地震资料表明,经过地层反滤波处理后的记录频率成分明显提升,地质构造更加准确、清晰。

When we encounter the complex faulted patterns or obscure stratigraphic plays,we need the available bandwidth of the data.A principal limitation on seismic resolution is the earth attenuation, or Q—effect,including the energy dissipation of high frequency wave components and the velocity dispersion that distorts seismic wavelets.This article describes a new method for stratigraphic deconvolution that is based on the frequency decay experienced at different VSP depth levels in a well. We use the Wiener filter to get the deconvolution operators to deconvolution the seismic section and get the result with higher frequency and more subtle stratigraphic information which can lead to more accurate interpretation.