海上地震勘探罗经鸟数据对拖缆空间位置的影响

Compass data influence on towed streamer positioning in marine seismic

拖缆地震勘探是海洋石油勘探的主要方法。本文首先介绍了拖缆地震勘探中电缆罗经鸟的作用和空间分布;阐明了基于罗经鸟数据确定拖缆空间形态的拟合和积分方法;分析了磁偏角改正和子午线收敛角改正对电缆空间位置的影响。在对现场采集数据进行计算分析后认为:磁偏角和子午线收敛角对拖缆的定位计算具有重要意义,在定位网络计算中须对每个罗经鸟的方位数据进行精确的磁偏角改正和子午线收敛角改正,以提高拖缆空间位置精度,满足现场地震数据采集部署及安全作业的需要。

Towed streamer is the main tool of offshore seismic explorations.We firstly introduce in this paper the distribution of compasses and their role in towed streamer seismic exploration,and then explain how to use the compass data to determine streamer shape by fitting and integral methods,and discuss the influences of the declination corrections and meridian convergence corrections on the streamer spatial position.Based on the field data analysis,the following observation are obtained:Accurate corrections of the magnetic declination and meridian convergence angle are very important for the streamer positioning;the magnetic declination corrections and meridian convergence must be add to every compass data in network computing in order to improve the accuracy streamer positioning and meet the needs of field operation.