Common Reflection Angle Migration for improved prediction of structure and reservoir in structurally complexe regime

We present a new seismic subsurface imaging technology for generating high-resolution, amplitude preserved angle dependent reflectivity gathers and image volumes in the local angle domain. Such local angle domain common image gathers can be obtained from a multi arrival, ray based Common Reflection Angle Migration (CRAM) creating a uniform illumination at the image points from all directions. In order to improve initial velocity models, residual move-outs associated with CRAM gathers on the subsurface image points are measured by automatic picking of horizontal or vertical semblances along the geological horizons, smoothed and used in vertical and/or tomographic update. Anisotropy parameters are successfully tested using CRAM on land and transition zone data sets, examples of isotropic and anisotropic CRAM imaging results are shown in comparison with conventional Kirchhoff Migration.