一种精确消除倾斜地层对相干值影响的方法

A precise algorithm to eliminate effects of slope on seismic coherence

相干属性是检测地下介质不连续特征的主要技术之一,但倾斜地层会使相干值产生畸变,故在计算相干属性之前需进行倾角搜索或对地震数据做层拉平处理。为获取更精确的地层倾角用于频率域层拉平,引入并改进了一种在频率域内的地层倾角估算法,总结出一套融合时间域倾角搜索和频率域倾角估计的层拉平算法流程。实际地震数据的应用结果表明,这种联合利用时间域—频率域的层拉平算法可更彻底消除地层倾角对相干属性的影响。

Seismic coherence is one of major attributes to detect discontinuities of underground layers.Because dips have effects on seismic coherence,dip steering or horizon flattening has to be applied to seismic data before coherence calculation.However both dip steering in the time domain and horizon flattening methods in the frequency domain have precision limitation.This paper proposes a new algorithm for dip estimation based on short time Fourier transform(STFT)in frequency domain,and a processing flow for both the time-domain dip correction and the frequency-domain dip correction.Real seismic data applications show that the proposed approach is more effective for eliminating effects of dip on seismic coherence calculation.