f Mapping outside borehole reflectors with crosshole reflection imaging

An attempt to image outside of inter-well area has been made with crosshole reflection imaging technique. A computer and physical model with reflectors in both sides of inter-well area and beneath inter-well area were created for investigation. Prestack reverse time migration applied on crosshole common shot gathers successfully imaged reflectors outside boreholes area. Combined migration of crosshole and reversed VSP data sets increased the image quality substantially. Combination of this method and crosshole tomography is recommended for accurate, high-resolution survey of the near surface.