非规则噪音地震记录的优化加权叠加

Optimum weighted stacking of seismic record with irregular noises

中国石油勘探开发研究院, 中国石油勘探开发研究院 北京 100083, 北京 100083

CNPC Research Institute of Petroleum Exploration and Development, Beijing 100083, China

提出了一种改善地震记录信噪比的新方法。首先采用一个新的信号模型,即假设信号具有相同的形状,但具有不同的振幅值;然后在动静校正后的CMP道集内,采用简捷的算法来估算信号的振幅成分和噪音的协方差矩阵;最后由信号的振幅和噪音协方差矩阵来确定每道的优化加权因子并作加权叠加。通过实际资料的验证,说明该方法比常规直接叠加方法更能提高地震记录的信噪比。

The paper presents a new method for improving S/N ratio of seismic records. The method uses a new signal model, that is, the signal components are supposed to have a constant shape while their amplitudes vary across the traces. Then, the signal amplitudes and noise covariance matrices are estimated by using an algorithm in CMP gather after static and normal moveout. Finally, the optimum weighting factor of each trace is determined with the signal amplitudes and noise covariance. Optimum weighted stacking is carried out with the resulting factors. Tests with real data show that the method is more effective in improving the S/N ratio of seismic records than conventional straight stacking.