摘要
从声波方程出发,应用互换原理,使用两次克希霍夫积分,推导了包括震源和检波器双重外推的积分表达式.包括近场和远场项.对于较简单的介质,利用均方根速度近似求取波的传播时间;对于横向剧变介质,采用射线追踪法求取传播时间.通过对每一对震源和检波器组合作倾角滤波,可以有效地压制画弧现象.理论和实际数据的偏移例子说明了该方法的正确性.
From the scalar wave equation, by invoking the principle of reciprocity and applying the kirchhoff integral twice, we can arrive at an integral expression which includes dual extrapolation of sources and recivers. The integral expression includes both the near-field and the far-field terms. It is adequate foe many simple subsurface structures to compute the wave travel time by root-mean-square (RMS) velocity, but when the known subsurface structure changes laterally and significantly, the wave travel time is copmuted by ray-tracing method. The ellipse noise can be greatly reduced by a dip-filter which is designed by us. The migration experiments of the synthetic and real VSP data show that the method is correct and practical.
基金
中国石油天然气总公司物探局研究院
关键词
地震勘探
剖面
克希霍夫积分
偏移
vertical seismic profile, migration, kirchnoff integral
