面向目标宽频采集的海上缆型设计方法及应用

Research and Application of Streamer Shape Design of Broadband Acquisition in Target Exploration

海洋拖缆勘探中,鬼波是限制地震资料频带宽度进而影响地震资料品质的一个重要因素,震源沉放深度及电缆沉放深度会直接影响鬼波陷波点位置,从而直接改变整个地震资料原始频谱。随着海洋地震宽频采集多年来的发展,发展出了诸如直斜缆采集、抛物型斜缆采集、“犁式”斜缆采集等多种变深度缆采集方式。为了进一步研究在采集中消除鬼波的定量化设计方法,本文从传统鬼波去除机理入手分析,提出使用多道叠加的方式在采集端进一步压制鬼波,通过理论公式推导出了影响多道叠加响应的关键参数,最终,通过最不相关准则,给出满足目标勘探区的缆型设计结果。本方法适用于各种水深地区,可根据多个目的层进行设计并拟合出最优缆型,实际采集资料宽频处理效果,验证了面向目标宽频采集的海上缆型设计方法的可靠性。

Ghost is one of the key factor that limits the frequency band width of seismic data and affects the quality of seismic data in marine exploration.The depth of source and streamer directly affects the location of the point on the notch and then changes the spectrum of the seismic data.With the development of broadband acquisition in marine seismic over the years,such methods as acquisition with Variable Depth Streamer,Plow Streamer are coming to the spotlight.In order to study the method of attenuation ghost in acquisition,this paper,starting with the theory of deghost,using stacking of multi irrelevant channels to attenuate ghost,puts forward the method of streamer shape design through reduction.The method applies to different areas of water depth,and the optimal cable pattern can be designed and fitted according to multiple target layers.The broadband processing effect of the actual collected data verifies the reliability of the offshore cable pattern design method for target broadband acquisition.