角道集波形校正方法

Angle gather waveform correction method

通常纵波入射且当入射角大于临界角时,由于反射系数的变化,角道集记录发生相位畸变,为实现同相叠加,要在叠加之前进行相位校正。本文针对要校正的相位角和振幅值在各个时间段上并非常数的实际情况,对角道集记录进行了分时窗处理。分别应用分时窗常相位校正和直接利用波形校正因子对模型和实际井资料的角道集记录进行校正,并就时窗长度对校正结果的影响进行了分析。从对比分析校正前、后的角道集记录可以看出,分时窗常相位校正方法和波形校正因子校正方法可以有效校正波形畸变,提高叠加剖面质量。

Normally when incidence is P-wave and angle of incidence is larger than critical angle,the phase distortion will be found in the angle gather record due to reflection coefficient change.In order to same phase stacking for seismic data,phase correction should be conducted before stacking.As the values of the phase angle and amplitude which will be applied in the correction are not the constant over the time windows,the angle gathers have to be processed in their individual windows.In this paper the constant phase correction were conducted in the individual windows,and correction for angle gather of model and real well data was also carried out by directly using waveform correction factor,and how the time window length affecting the correction results is analyzed as well.If comparing pre-correction angle gather records with the post-correction ones,it is easily found out that the two methods(the constant phase correction method in individual windows and the waveform correction factor method) work well,can correct the waveform distortion and can raise the quality of seismic stacking sections.