海底电缆陆检噪音衰减方法及其在乌石地区的应用

Geophone noise attenuation of ocean bottom cable and its application in Wushi area

海底电缆采集方式不同于传统的海洋托缆地震资料采集,检波器放在海底进行地震信号接收,一般是多分量检波器。检波器由于和海底的耦合性不好,一般信噪比较低,接收到的有效信号很弱,而地滚波和转换横波等噪音能量很强;其中转换横波对信号的干扰较大,也较难衰减。通过对乌石工区海底电缆资料进行统计分析,发现数据在共检波点域转换横波噪音相干性较好,于是在共检波点域使用τ-p变换方法将转换横波从数据中分离出来,分离转换横波后的陆检分量数据信噪比获得了极大的提高。

The ocean bottom cable acquisition method is different from the traditional marine cable seismic ac- quisition. The receiver cable is located in the bottom of the ocean and is generally more component geophone. Be- cause of the geophone and the seabed is not coupled, the SNR of the geophone data is low. The signal received is very weak, but the noises like rolling wave and the converted shear wave are strong. In addition, converted shear waves as the main interference is difficult to suppress. Through the analysis of the OBC data in Wushi area, the au- thors found that converted shear wave coherent is good in common receiver domain. Therefore, the method of τ-p transform was used to suppress converted shear waves in common receiver domain. Finally, the SNR of the geo- phone data was greatly improved after converted shear wave separated.