In crosswell seismic, imaging section produced by migration employed with wave equation has a serious arc phenomenon at its edge and small effective range due to the restriction of geometry. Another imaging section produced by VSP-CDP stack imaging employed with ray-tracing theory is amplitude-preserved but has difficulty in imaging 3D complex lithological structure accurately. Therefore, the paper proposes inverse Gaussian beam stack imaging in 3D crosswell seismic of deviated well based on the Gaussian beam ray-tracing theory. Through employing Gaussian beam ray-tracing theory into 3D crosswell seismic, the energy relationship between the seismic wave field and its effective rays is analyzed. Then the author converts the single channel seismic wave field data in the common shot point (CSP) gather into multiple effective wave fields in common reflection point (CRP) gather by inverse Gaussian beam when imaging and thus produces more intensive reflection points fold number. Finally, the wave fields of the effective reflection points in the same stack bin, selected from horizontal and vertical direction of the 2D measuring line, are projected onto the 2D measuring line, chosen according to the distribution characteristics of the reflection points, and stacked into an imaging section. The method is applied in X oilfield to identify the internal structure of offshore gas cloud area. The result provides positive support for inverse Gaussian beam stack imaging in producing accurate imaging in 3D complex lithological structure and make it a powerful imaging tool for 3D crosswell seismic data processing.

在井间地震中，由于波动的影响，采用波动方程产生的成像剖面在边缘处具有严重的电弧现象，并且由于几何形状的限制而具有较小的有效范围。由采用射线追踪理论的VSP-CDP堆栈成像产生的另一个成像部分可以保留振幅，但是很难准确地成像3D复杂岩性结构。因此，本文提出了一种基于高斯光束射线追踪理论的偏井3D井间地震高斯光束叠加成像方法。通过将高斯光束射线追踪理论应用于3D井间地震中，分析了地震波场与其有效射线之间的能量关系。然后作者在成像时利用逆高斯光束将公共炮点（CSP）道集中的单通道地震波场数据转换为公共反射点（CRP）道集中的多个有效波场，从而产生更密集的反射点倍数。最后，将同一堆叠箱中的有效反射点的波场（从2D测量线的水平和垂直方向选择）投影到2D测量线上，根据反射点的分布特性进行选择，然后堆叠为成像部分。将该方法应用于X油田识别海上天然气云区内部结构。