Detailed Velocity Model of the Nile Delta Using Multi-azimuth (MAZ), Multi-Parameter Reflection Tomography

Abstract

SUMMARYIn the Nile Delta, a complex and dipping water bottom, shallow gas filled channel systems and the evaporitic Messinian interval have prevented the creation of an accurate velocity model in depth using conventional 3D data. By designing a workflow that combines the Multi-Azimuth data in a multiparameter reflection tomography approach, we have built a detailed velocity model that shows variations that correspond very well to the geology interpreted from the seismic, and which yields improved images at depth. SummaryBuilding a detailed velocity model is always a major challenge in seismic data processing. In the Nile Delta, a complex and dipping water bottom, shallow gas filled channel systems and the evaporitic Messinian interval have prevented the creation of an accurate velocity model in depth using conventional 3D data. Can we take advantage of the recently acquired Multi-Azimuth (MAZ) seismic to build a detailed velocity model? We know from theory and case histories that Multi-Azimuth data will give us improved signal to noise, improved multiple attenuation, and improved illumination. By designing a workflow that combines the Multi-Azimuth data in a multi-parameter reflection tomography approach, we have built a detailed velocity model that shows variations that correspond very well to the geology interpreted from the seismic, and which yields improved images at depth.Background