共成像点道集(CIG)叠加方法研究

Studies on Common Imaging Gather (CIG) stacking.

在构造复杂区的地震数据处理中,叠加速度往往难以准确求取,本文在等效炮检距方法(EOM)基础上提出了共成像点道集(CIG)叠加方法。该方法无须预先知道任何速度信息,通过基于波阵面曲率的空间—时间域几何变换,将多个CMP道集变换成为单一的CIG共成像点道集。由于消除了界面倾角影响,其反射能量更聚焦,而且地震资料的信噪比得到提高。通过对准噶尔盆地天山地区正演构造模型和陆东地区实际二维地震资料的处理,取得了较好的效果。

In seismic data processing for the complicated geological structure area, stacking velocity is usually difficult to estimate. Based on equivalent offset migration method (EOM), the Common Imaging Gather (CIG) method is proposed in this paper. This method does not need to know any velocity information, through geometrical transformation in space-time domain, which is based on wave front curvature ratio, the method converts multi CMP gathers into one common imaging gather. As the method removes the influence of interface dip, the reflection energy becomes more focusing and data S/N ratio is improved . By using this method the forward structure model data in Tianshan area of Junggar Basin and the real 2D seismic data in Ludong area were processed, good processing results were obtained.