井间地震反射波场分离及应用研究

摘要:

井间地震反射波场分离可以看成是VSP波场分离的一种延伸。与VSP不同，井间地震波场较为复杂，分离的难度较大。借鉴VSP波场分离技术与常规地面地震处理技术，系统论述了实际井间地震反射波场分离的过程：①建立井间地震反射波场分离的工作流程；②进行井间地震初至波（直达P波）的切除；③运用多域多道滤波技术分离出上、下行一次反射波；④运用VSP-CDP成像技术与初步叠加技术获得类似于地面地震资料的井间地震反射波初叠剖面。实际资料处理表明，运用多域多道滤波技术可以较好地实现井间地震波场的分离。

Abstract:

Wavefield separation of seismic crosshole method is an extension of VSP wavefield separation. Compared with VSP, the separation of crosswell wavefields is more difficult, because of the complicated seismic crosshole wavefields. With the help of VSP wavefield separation techniques and surface seismic data processing techniques, we separate the real seismic crosshole successfully. The methods used in the wavefield separation are presented. At first, the flow of wavefield separation is established. Second, the P direct arrival (the first arrival) is muted by fk fan filter in CRG. Third, multichannel wavefield separation filters in different domains separate the upgoing and downgoing reflection waves. Finnaly, the high resolution reflection image is obtained by VSP-CDP algorithm. The real seismic crosshole data processing shows the seismic crosshole can be separated by multichannel wavefield separation filters and imaged by VSP-CDP mapping correctly.