Hassan Khaniani

Enhancing the Inversion of Migration Velocity By Implementation of Tilt Effects On CSP Data

Equivalent Offset Migration (EOM) is based on the prestack Kirchhoff time migration (PSTM) method. It first maps the energies of the scatter points onto an intermediate Common Scatter Point (CSP) gathers, then after successfully applying a Normal Move Out (NMO) correction will output the migrated image. Assuming negligible lateral velocity gradient, the CSP data are sorted along the normal hyperbolic paths and serve as a useful tool for velocity inversion. The scatter point response below the dipping interface is a tilted hyperbola. Using the constructed wavefront we established the relationship between the tilted and normal hyperbolae. Similar relationship is obtained by simulation of CSP responses. We improved the focusing of the separated energy in the semblance plots by removing the tilt effects. As a result, the accuracy of migration velocity inversion enhanced and the focusing of output image of time migration are improved.