当前VSP偏移方法多数只利用到资料中的上行反射波，大量下行多次波信号未得到有效利用。这类方法仅能对井旁局部范围成像，而且受波场分离效果的影响。近年来提出的新型多次波或全波VSP成像技术仍存在一些问题待讨论和改善：比如波场分离和保幅处理等问题降低了射线类方法的效率和效果；存储开销和计算效率等问题制约了波动类方法的推广应用。.稳健的VSP偏移成像方法应该兼顾以下考虑：能利用到主要的多次波信号，减少或者无需波场分离，具有一定的保幅能力以及尽可能高效快捷。本项目拟研究基于广义Radon变换(GRT)偏移的VSP成像方法，充分挖掘VSP数据高分辨率高信噪比的优势，同时利用VSP数据中的上、下行全波场信息进行联合成像。该方法不需要进行波场分离，能结合两类信号成像的优点，高效实现井旁和远井区域的宽范围高精度保幅成像。

Conventional seismic imaging methods for VSP data mostly use the upgoing primary wavefield only, and large amounts of downgoing multiples have not been used effectively. The image from these kinds of methods is limited to a local area around the borehole, and also suffers from incomplete wavefield separation processing. There are still some problems to be discussed and improved in the new VSP imaging methods using multiples or full-wavefield proposed in recent years. For instance, the wavefield separation and amplitude preserving processing reduce the efficiency and effectiveness of ray-based methods. The storage cost and computational efficiency also limit the application of wavefield-based method..The robust VSP migration imaging method should take into account the following considerations: using the dominant multiple wave signals, reducing the wavefield separation or no separation, showing amplitude-preserved ability, high efficiency and convenience. This research intends to study the VSP imaging method based on the generalized Radon transform (GRT) migration, which can fully take advantages of high resolution and high SNR of VSP data. And also, full-wavefield information containing upgoing and downgoing wavefields is used for joint imaging. The proposed method does not require wavefield separation and can combine the advantages of the two kinds of signals, which contributes to achieving high-precision imaging of the subsurface in the vicinity of the borehole also away from it efficiently.