Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Geophysics

Seismic Processing techniques are essential and very critical in order to enhance the poor seismic imaging and non-hyperbolic moveout anomalies. Several analyses and tests based on the complexity of the structure and the acquisition type, including Narrow Azimuth, Multi Azimuth or Wide Azimuth were complied in order to alleviate the effect of fault shadow zone, in addition to improving fault planes terminations and seismic reflectors continuity. However, 3D {u2013} Seismic land data (Wide Azimuth {u2013} WAZ) showed optimal results and successfully enhanced the data. Published work highlighted the need for accurate depth velocity models in order to overcome the fault shadow problems.Therefore, the offset-azimuth information was utilized to update, enhance and improve the velocity model and the imaging output, and to apply the residual moveout analysis post migration. Conventional seismic processing flow applied up to step of data regularization and interpolation. Four main seismic processing techniques wer implemented in the workflow to sort out the imaging distortions. Firstly, Common Offset Vector binning was used for pre-stack migration step to keep post-imaging offset-azimuth information.Secondly, Depth velocity modeling phase is comprised of building Initial Anisotropic velocity model, then applying Non-linear tomographic tool for velocity model updating; using two approaches for Residual Moveout (RMO) picking, WAZ and MAZ RMO pickings.The final tomographic velocity model was calibrated to wells.Then, Kirchhoff pre-stack depth migration tool was applied in the imaging phase, while, finally, high density RMO velocity analysis and trim statics were applied in the post imaging phase, in order to correct the azimuthal variation on the migrated gathers. Eventually this workflowsuccessfully alleviate fault shadow effects, improve the imaging of the reflectors and the areas around the fault planes

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