Common Reflection Point Migration Velocity Analysis with Anisotropic Parsimonious Depth Migration

Abstract

Summary An efficient prestack depth migration, called ‘parsimonious’ migration was developed isotropic media a decade ago. The common-reflection point (CRP) migration velocity analysis was developed later for isotropic media. In this paper, both methods are extended for application to 2D tilted transversely isotropic (TTI) media and illustrated with synthetic data. The extension to TTI media requires redevelopment of each of the numerical components. The model parameterization consists of Thomsen’s parameters. The common-reflection point migration velocity analysis for TTI media for P-waves includes (and inverts for) Vpo, ε and δ. The orientation of the anisotropic symmetry axis have to be constrained. If it constrained orthogonal to the layer bottom, it is estimated at each CRP and updated at each iteration without intermediate picking. The extension to TTI media requires development of a new inversion procedure. The TTI CRP MVA is applied to a version of the TTI BP model by layer stripping. Vpo, δ and the orientation of the anisotropic symmetry axis (constrained orthogonal to the local reflector orientation) are successfully inverted. ε is less well constrained by the small acquisition aperture in the data. Previously published as part of Oropeza, Ernesto V., and George A. McMechan, 2014, Common-reflection-point migration velocity analysis of 2D P-wave data from TTI media. Geophysics, 79, no. 3, http://dx.doi.org/10.1190/geo2013-0295.1. Reproduced as abstract for EAGE with permission from SEG.