VSP与地面地震资料的联合偏移处理

本文利用双程全波波动方程,采用有限差分算法,沿逆时方向对源点波场和记录波场进行延拓,并借助于 Claerbout 成像条件,实现了 VSP 与地面地震资料(SRP)的联合偏移处理。方法的关键在于利用了自由面产生的下行多次反射波信息,以扩大 VSP 成像的范围。采用这种宽孔径成像方法的结果表明,即使对单个共炮点道集也能收到相当好的成像效果。方法的另一个特点在于波场外推是对整个记录进行的,因此,处理中不需要特地识别初至,也不需要分离上行波和下行波。对合成数据的应用表明,该算法具有良好的效果和潜力。

and surface reflection profiling data

Both source wave fietd and receiver wave field are continued along reverse-time direction by making use of two- way full wave equation and finite difference method.Then,the simultaneous migration of VSP data and surface reflection profiling data can be achieved with the use of Claerbout image conditions.The essential of this method is to use downgoing multiples generated from free surface,so as to enlarge VSP image extent.The use of wide aperture image method even makes single common-shot gather find quite good image result.Further- more,the extrapoiation of wave field is performed on whoie seismic section so that there is no need to identify first break and to separate upgoing wave from downgoing wave in data processing.The application of this method to synthetic data shows its good effect and potential.