海底电缆初至波二次定位技术的应用

Application of first break second positioning technique in OBC

中国石油集团东方公司海上勘探事业部海龙公司,天津塘沽300457

Tianjin HiLong Geophysical Co., Ltd., Tanggu 300457, China

浅海勘探中压电检波器需要放置在海底, 目前大多数的作业是采用抛掷的方式。海底电缆也是采用机械放缆的方式将电缆和检波器铺设到海底, 同时记录下检波器离开放缆船的位置。检波器在到达海底的过程中, 会受到海流、潮汐、船速的影响而偏离设计位置, 因此有必要进行二次定位来确定其在海底的准确位置。初至波二次定位方法, 能够利用准确的速度模型和大量的数据进行冗余计算, 从而提供准确的检波器位置, 为后期的资料处理和解释增加可信度。

Hydrophones should be deployed on the seabed in shallow water operation. The locations of the hydrophones from the vessel are recorded in real time while the cables and hydrophones are laid out on the seabed by mechanical equipment in OBC operation. However, the hydrophones could deviate from its designed position due to current, tide and the speed of the cable vessel. It is very important to relocate the real positions of the hydrophones on seabed. First break second positioning technique can provide accurate positions of the hydrophones by building of accurate velocity model and redundant computation on abundant data, which improves the reliability of subsequent data processing and interpretation.