一种基于高频噪声定量约束函数的地震高分辨率处理方法

A high-resolution seismic processing method based on quantitative constraint function of high-frequency noises

系统分析了现有地震数据高分辨率处理方法的适用性及不足,探索了一种基于高频噪声定量约束函数的高分辨率处理方法,有效且保真地提高地震资料信噪比与分辨率。通过分析叠后地震数据有效信号带宽,设计了压制高频噪声的最大概率准则和定量约束函数,通过多次迭代压制噪声,提高全频带信号的信噪比,逐步分级拓宽地震有效频带宽度,循环迭代求取反射系数,将提取的地震子波与反射系数褶积得到高分辨率地震数据体。测试校验对比其它高分辨率地震处理结果,处理后的数据体具有垂向分辨率高、主频高且频带宽的特点,有效视主频由50 Hz提高至100 Hz左右,地质目标视分辨率相应提高近1倍。基于该提频数据与波阻抗反演实现了2~5 m地质目标的定性与定量预测,钻井验证符合率90%以上,有效指导井位部署。该方法弥补了在传统“有效带宽”内提高地震高频信号的不足,实现了全频带内重构高、低频有效信号的目的。

Based on the discussion of the applicability and limitations of existing high-resolution processing techniques,we propose a new method based on the quantitative constraint function of high-frequency noises to improve seismic resolution and signal-to-noise ratio in the context of amplitude preservation.In view of the effective bandwidth of poststack seismic data,we formulate the maximum probability criterion and quantitative constraint function for iterative high-frequency noise reduction to expand effective frequency band step by step and improve the signal-to-noise ratio of full-band data.Reflection coefficients calculated iteratively are convolved with seismic wavelet to obtain high-resolution seismic data.Compared with other high-resolution processing techniques,our method yields a data volume with high vertical resolution,high dominant frequency,and wide band;effective apparent dominant frequency increases from 50 to 100 Hz,and apparent resolution nearly doubles.Based on the frequency data and wave impedance inversion,the qualitative and quantitative prediction of 2~5 meters geological targets is realized,and the verfication test matches with more than 90%of the targets,which effectively guides the well location deployment.This new method performs better than routine techniques in high-frequency signal enhancement within the effective frequency band and thus realizes high-and low-frequency signal reconstruction for full-band data.