Focusing in dip and AVA compensation on scattering‐angle/azimuth common image gathers

Common image gathers (CIGs) in the offset and surface azimuth domain are used extensively in migration velocity analysis and amplitude variation with offset (AVO) studies. If the geology is complex and the ray field becomes multipathed, the quality of the CIGs deteriorates. To overcome these problems, the CIGs are generated as a function of scattering angle and azimuth at the image point. The CIGs are generated using an algorithm based on the inverse generalized Radon transform (GRT), stacking only over migration dip angles. Including only dips in the vicinity of the geological dip, or focusing in dip, suppresses artifacts in and results in improved signal‐to‐noise ratio on the CIGs.Migration velocity analysis can be based upon the differential semblance criterion. The analysis~is~then carried out by minimizing a functional of the derivative of the CIGs with respect to horizontal coordinates (offset/azimuth or scattering‐angle/azimuth), but AVO/amplitude variation with angle (AVA) effects will degrade the...

[1]  Bjørn Ursin,et al.  Velocity Analysis In the Common Scattering-angle/azimuth Domain , 1999 .

[2]  M. V. Hoop,et al.  The resolving power of seismic amplitude data: An anisotropic inversion/migration approach , 1999 .

[3]  Ketil Hokstad,et al.  Multicomponent Kirchhoff migration , 2000 .

[4]  William W. Symes,et al.  Velocity inversion by differential semblance optimization , 1991 .

[5]  Leon Thomsen,et al.  Converted-wave reflection seismology over inhomogeneous, anisotropic media , 1999 .

[6]  Christiaan C. Stolk,et al.  Microlocal analysis of a seismic linearized inverse problem , 2000 .

[7]  Maarten V. de Hoop,et al.  Generalized Radon transform inversions for reflectivity in anisotropic elastic media , 1997 .

[8]  Douglas E. Miller,et al.  Generalized radon transform/amplitude versus angle (GRT/AVA) migration/inversion in anisotropic media , 1994, Optics & Photonics.

[9]  Shouhuai Xu,et al.  Common angle image gather-A strategy for imaging complex media: 68th Annual Internat , 1998 .

[10]  Gilles Lambaré,et al.  Two-dimensional multivalued traveltime and amplitude maps by uniform sampling of a ray field , 1996 .

[11]  John P. Castagna,et al.  Offset-dependent reflectivity : theory and practice of AVO analysis , 1993 .

[12]  The Information Content of the Elastic Reflection Matrix , 1996 .

[13]  Phase Shift of the Green Function Due to Caustics In Anisotropic Media , 1997 .

[14]  Maarten V. de Hoop,et al.  Quasi-Monte Carlo integration over for migration inversion , 1996 .

[15]  Maarten V. de Hoop,et al.  Microlocal analysis of seismic inverse scattering in anisotropic elastic media , 2002 .

[16]  Olav I. Barkved,et al.  Converted wave imaging of Valhall reservoir , 1997 .

[17]  Gregory Beylkin,et al.  A new slant on seismic imaging: Migration and integral geometry , 1987 .

[18]  Efficient 2.5-D true‐amplitude migration , 1999 .

[19]  Jon F. Claerbout,et al.  Imaging the Earth's Interior , 1985 .

[20]  Gregory Beylkin,et al.  Linearized inverse scattering problems in acoustics and elasticity , 1990 .

[21]  N. Bleistein.  On the imaging of reflectors in the earth , 1987 .

[22]  B. Ursin,et al.  Reciprocal volume and surface scattering integrals for anisotropic elastic media , 1997 .

[23]  Fabio Rocca,et al.  Eigenvalues and eigenvectors of linearized elastic inversion , 1993 .

[24]  Maslov asymptotic extension of generalized Radon transform inversion in anisotropic elastic media: a least-squares approach , 2000 .

[25]  H. Chauris,et al.  Two-dimensional velocity macro model estimation from seismic reflection data by local differential semblance optimization: applications to synthetic and real data sets , 2001 .