共转换点道集的抽取与转换波时变静校正

纵横波速度比固定时,同一地震道中各时间采样点对应不同的转换点位置,因此,常规的整体抽道方法只能抽取特定深度或特定层位条件下的共转换点道集,它不能保证所有P-SV转换波的反射点位置都在同一水平位置处。提出了一种精确抽取共转换点道集的新方法,运用这种方法抽取的共转换点道集中所有数据对应的转换点在地面的投影都对应于同一位置,因此,该道集是一种真正意义上的共转换点道集,在此基础上提出了一种解决短波长问题的转换波时变静校正方法,实际资料处理取得了好的效果。

COMMON CONVERSION POINT GATHERING AND TIME-VARIANT STATIC CORRECTION

When the velocity ratio between compressional wave and shear wave is fixed,the horizontal location of conversion point of each sample in a trace is different,so the traditional method of trace gathering can only gather the common conversion points(CCP) of a certain depth,which cannot guarantee that all the samples' conversion points are at the same location.In this paper,the authors present a new method for CCP binning,and the CCP gather obtained from this method is a really CCP gather in which the projection of all samples' conversion points are at the same location.Based on this method,a time-variant short-wavelength static correction method for converted waves is proposed and the real data processing results prove the method feasible and effective.