Inverse gaussian beam stack imaging in 3D crosswell seismic exploration of deviated wells and Its application

In crosswell seismic exploration, the imaging section produced by migration based on a wave equation has a serious arc phenomenon at its edge and a small effective range because of geometrical restrictions. Another imaging section produced by the VSP-CDP stack imaging method employed with ray-tracing theory is amplitude-preserved. However, imaging 3D complex lithological structures accurately with this method is difficult. Therefore, this study proposes inverse Gaussian beam stack imaging in the 3D crosswell seismic exploration of deviated wells on the basis of Gaussian beam ray-tracing theory. By employing Gaussian beam ray-tracing theory in 3D crosswell seismic exploration, we analyzed the energy relationship between seismic wave fields and their effective rays. In imaging, the single-channel seismic wave field data in the common shot point gather are converted into multiple effective wave fields in the common reflection point gather by the inverse Gaussian beam. The process produces a large fold number of intensive reflection points. Selected from the horizontal and vertical directions of the 2D measuring line, the wave fields of the effective reflection points in the same stack bin 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 to X oilfield to identify the internal structure of the offshore gas cloud area. The results provided positive support for the inverse Gaussian beam stack imaging of 3D complex lithological structures and proved that technology is a powerful imaging tool for 3D crosswell seismic data processing.