8L4S176T观测系统在渤海CF区块海底电缆地震采集中的应用

An application of 8L4S176T observation system to seismic acquisition of ocean-bottom cable in CF block,Bohai Sea

为在渤海CF区块复杂过渡带获得高品质的地震采集资料,采用了8L4S176T观测系统,并在采集设备、震源选型、电缆铺设、二次定位等方面进行了详细论证;分析了采集作业过程中存在的施工效率低、潮流影响大、过往船只多等作业难点,提出了沿测线放炮、提前多铺设2根电缆、分时放炮、增加电缆配重、"圈地法"护缆等相应的技术措施,实施后取得了更丰富的波场信息,有效提高了地震资料分辨率,改善了该区块中深层复杂构造的成像精度。

In order to acquire excellent seismic data in the complex transitional zone of CF block, Bohai Sea, 8L4S176T observation system was applied, and several technical issues were appraised in detail, including acquisition equipment, source selec- tion, cable laying, secondary positioning, etc. For the operation difficulties, such as low efficiency,big impact of tidal current, and many passing ships, during seismic acquisition, a series of tech- nical measures were developed, including shooting along the survey lines, laying two more cables in advance, shooting at different time, increasing the cable weight, protecting cables with ＂an en- closure method＂ and other appropriate measures. The adoption of these measures has resulted in ac- quiring more information of wave field, improving effectively resolution of seismic data and increas- ing accuracy in imaging deep complex structures of the block.