Subsalt imaging of fine scale geological features with high resolution 3D VSP: A finite difference modelling study

Fine scale structural and stratigraphic geological features, such as faults and channels, are important in petroleum exploration and production. As surface seismic usually has difficulty in imaging these small (150 feet and smaller) faults and channels in deep subsalt reservoir, we investigate whether high frequency 3D VSP imaging can detect them. We first build a 3D TTI (transverse isotropy with tilted symmetry axis) model with fine scale faults and channels, then generate high frequency (48 Hz) 3D VSP data with TTI finite difference modelling (FDM) and image the data using reverse time migration (RTM). Results show that high frequency 3D VSP data provides high resolution images of these important geological features in the subsalt reservoir.