Publications

The NIP-wave tomographic inversion is an alternative method to build velocity model. The input of this method is accurate kinematic informations which are picked from the Common-Reflection-Surface (CRS)-stack section. The quality of this method much better than regular reflection tomography, because the picking is performed in stack section with the high S/N ratio. In addition, the picking can be achieved efficiently because the automatic picking performed is based on coherency section resulting from CRS-stack. The drawbacks of the regular reflection tomography can be improved by applying the accurate NIP-wave tomography. The objectives of our research are applying NIPwave tomographic inversion for velocity model building instead of reflection tomography which has disadvantages in picking kinematic information from pre-stack data. The velocity field is obtained iteratively by minimizing the misfit between picked seismic data and its current forward model. The forward modeling can be obtained by performing the kinematic and dynamic ray tracing. During this process the Fréchet derivative is calculated and also used to perturb current velocity model. The performance of the NIP-wave tomographic inversion has been applied to the synthetic data set and marine seismic data with low fold. The resulting velocity model is smooth and laterally heterogeneous and appropriate for ray tracing. The velocity is used as first approximation of velocity field for pre-stack depth migration and updates to obtain the final one iteratively. NIP-wave tomographic inversion yields smooth, isotropic and laterally heterogenous velocity model. This method can improve the limitations of reflection tomography. Keywords: tomographic inversion, CRS-Stackattributes