Orthorhombic velocity model building and imaging of Luda field with WAZ OBC data

In the oil rich Bohai area, Ocean Bottom Cable (OBC) acquisition has become the new trend with the benefit of operational flexibility, better illumination, better multiple elimination and better S/N for the targets at middle to deep depth. However, the presence of azimuthal anisotropy can cause severe imaging challenges in the Wide Azimuth OBC data, particularly fault imaging which is sensitive to velocity accuracy. Fault imaging can be smeared and fault shadow can be observed within complex strike-slip fault system if the azimuthal dependency of wave propagation is not properly honored. In this paper, we will present a new orthorhombic model building flow and demonstrate with Luda OBC data that our approach can successfully reconcile the structural discrepancies between seismic images from different azimuths, thus provide a clear and sharp fault image with the WAZ stacking process.