海洋地震资料中强能量噪声压制的分频振幅衰减法应用研究

Application of frequency-dependent amplitude attenuation method to suppress strong-energy noise in offshore seismic data

分频振幅衰减法将地震数据分为不同的频段范围,通过求取给定频率段不同时窗内地震样点的振幅强度,预测出强能量的噪声,以地震样点组的平均绝对振幅值作为标定,确定地震样点的振幅衰减曲线,采用时变的门槛值来有效压制强能量噪声干扰。东海某海域实际地震资料压噪处理的应用效果表明,分频振幅衰减法不仅适用于涌浪干扰、地震(船)干扰及强能量低频和高频干扰的压制,还能有效压制近道强能量剩余多次波,显著改善地震资料的信噪比。

Frequency-dependent amplitude attenuation method divides seismic data into different frequency band.Strong-energy noise can be identified by calculating amplitude strength of sampling points within the given frequency band and time window.The amplitude attenuation curve of the seismic sampling could be achieved by calculating every sampling ’s amplitude strength which is calibrated by the average absolute amplitude of the seismic sampling group.Then,the strong-energy noise can be effectively suppressed by applying time-variable threshold.The method is applied for noise elimination processing to offshore seismic data in the East China Sea,which shows that the method can completely suppress swell noise,seismic vessels interference and strong-energy noise with high or low frequency,and effectively suppresses the remaining multiples in near traces with great improvement of the S/N of offshore seismic data.