True-amplitude prestack depth migration

Most current true-amplitude migrations correct only for geometric spreading. We present a new prestack depth-migration method that uses the framework of reverse-time migration to compensate for geometric spreading, intrinsic Q losses, and transmission losses. Geometric spreading is implicitly compensated by full two-way wave propagation. Intrinsic Q losses are handled by including a Q -dependent term in the wave equation. Transmission losses are compensated based on an estimation of angle-dependent reflectivity using a two-pass recursive reverse-time prestack migration. The image condition used is the ratio of receiver/source wavefield amplitudes. Two-dimensional tests using synthetic data for a dipping-layer model and a salt model show that loss-compensating prestack depth migration can produce reliable angle-dependent reflection coefficients at the target. The reflection coefficient curves are fitted to give least-squares estimates of the velocity ratio at the target. The main new result is a procedure ...

[1]  R. L. Mills,et al.  ATTENUATION OF SHEAR AND COMPRESSIONAL WAVES IN PIERRE SHALE , 1958 .

[2]  J. Claerbout.  Toward a unified theory of reflector mapping , 1971 .

[3]  R. T. Shuey,et al.  A simplification of the Zoeppritz equations , 1985 .

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

[5]  G. McMechan,et al.  Reverse-time migration of offset vertical seismic profiling data using the excitation-time imaging condition , 1986 .

[6]  J. R. Resnick,et al.  Amplitude versus offset analysis in the presence of dip , 1988 .

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

[8]  A. J. Berkhout,et al.  Angle-dependent reflectivity by means of prestack migration , 1990 .

[9]  Paul Docherty,et al.  A brief comparison of some Kirchhoff integral formulas for migration and inversion , 1991 .

[10]  P. Hubral,et al.  True amplitude migration of 2D synthetic data , 1992 .

[11]  Viscoelastic attenuation, anisotropy, and AVO , 1992 .

[12]  Ketil Hokstad,et al.  Prestack depth migration with compensation for absorption and dispersion , 1995 .

[13]  S. Shapiro,et al.  Elastic waves in finely layered sediments : The equivalent medium and generalized O'Doherty-Anstey formulas , 1996 .

[14]  Samuel H. Gray,et al.  True-amplitude seismic migration: A comparison of three approaches , 1997 .

[15]  Christian Hanitzsch,et al.  Comparison of weights in prestack amplitude-preserving Kirchhoff depth migration , 1997 .

[16]  Adriansyah,et al.  Effects of attenuation and scattering on AVO measurements , 1998 .

[17]  Amplitude compensation of seismic data: application to masking by shallow bright spots , 1998 .

[18]  Causse Emmanuel,et al.  Viscoacoustic reverse-time migration , 2000 .

[19]  Paul Sava,et al.  Amplitude-preserved common image gathers by wave-equation migration , 2001 .

[20]  Paul Sava,et al.  Offset and angle-domain common image-point gathers for shot-profile migration , 2002 .

[21]  Yu Zhang,et al.  True amplitude wave equation migration arising from true amplitude one-way wave equations , 2003 .

[22]  Yu Zhang,et al.  Theory of true-amplitude one-way wave equations and true-amplitude common-shot migration , 2005 .