Multi-azimuth processing — the kinematics and dynamics of the azimuthal anisotropy, resolved by tilted orthorhombic tomography

Abstract

This paper explains a qualitative and quantitative approach to identify and resolve P-wave TTI and HTI variations in the depth migration velocity model building process. The combination of these effects can be represented by an orthorhombic model with three mutually orthogonal planes of mirror symmetry; the P-waves in each symmetry plane can be described kinematically as an independent TTI model. Orthorhombic velocity model building and imaging tools are required to address both HTI and TTI simultaneously in the subsurface. The orthorhombic anisotropy has been correctly identified and resolved, which has subsequently resulted in a high-resolution velocity model. A combination of the accurate velocity model building and advancement in the pre-processing techniques has shown significant uplift in the image quality on the earlier processing. The reprocessed PreSDM has provided improved coherency, recovered improved bandwidth, enhanced character, and better fault plane definition.