海底电缆双检接收技术压制水柱混响

海底电缆双检接收技术是20世纪80年代末出现的勘探新技术,主要用于压制在海底和海面之间存在的“水柱混响”干扰,能有效地提高地震资料的信噪比。此法的关键在于将海底电缆沉放到海底或水下一定深度,然后在同一观测点上同时利用压电检波器和垂直速度检波器接收地震记录,由于这两种检波器对水柱混响具有相反的响应,据此即可对两类检波器接收的地震记录分别处理,再将两者相加,即可达到有效信号增强、水柱混响去除的效果,该技术已经成为海底电缆勘探的标准。我国于20世纪90年代末引进该项技术,但由于受到处理技术的限制,一直未能取得较好的效果。本文在深入研究该项技术的基础上,结合实际资料的特点,提出一整套数据处理思路,着重强调做好双检记录的频率匹配,以便获得最佳的效果。

Using OBC dual-receiver to suppress reverberation of water column.

OBC dual-receiver is a new-developed exploration technique in the late eighties of last century, which is mainly used to suppress "water column reverberation" interference appeared between sea bottom and sea level that resulted in effectively improving S/N ratio of seismic data. The key of the method is to lower the OBC at sea bottom or a certain depth level under the sea,then the seismic data are simultaneously recorded by hydrophone and vertical velocity geophone at same survey point. Because the both geophones have opposite response to water column reverberation,the seismic data received by two kinds of geophone can be separately processed,the output results then are added and finally the records that both strengthen useful signal and eliminate water column reverberation can be reached. The technique has already become the criterion of OBC exploration. The technique has been imported in China in the late nineties but good results have not been achieved because of the limitation of processing techniques. On the basis of deeply studying the technique and in combining with practical data,the paper put forward a set of data processing ideas, in which the match of frequency in dual-receiver records is emphasized. The good results can be gained only in that way.