Multicomponent prestack depth migration using the elastic screen method

A 3D multicomponent prestack depth-migration method is presented. An elastic-screen propagator based on one-way wave propagation with a wide-angle correction is used to extrapolate both source and receiver wavefields. The elastic-screen propagator neglects backscattered waves but can handle forward multiple-scattering effects, such as focusing/defocusing, diffraction, interference, and conversions between P- and S-waves. Vector-imaging conditions are used to generate a P-P image and a P-S converted-wave image. The application of the multicomponent elastic propagator and vector-imaging condition preserves more information carried by the elastic waves. It also solves the polarization problem of converted-wave imaging. Partial images from different sources with correct polarizations can be stacked to generate a final image. Numerical examples using 2D synthetic data sets are presented to show the feasibility of this method.

[1]  Robert E. Sheriff,et al.  Encyclopedic dictionary of exploration geophysics , 1973 .

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

[3]  R. Sun,et al.  Phase correction in separating P‐ and S‐waves in elastic data , 2001 .

[4]  G. H. F. Gardner,et al.  FORMATION VELOCITY AND DENSITY—THE DIAGNOSTIC BASICS FOR STRATIGRAPHIC TRAPS , 1974 .

[5]  D. Ristow,et al.  Fourier finite-difference migration , 1994 .

[6]  Ru-Shan Wu,et al.  Wide-angle elastic wave one-way propagation in heterogeneous media and an elastic wave complex-screen method , 1994 .

[7]  G. McMechan,et al.  Elastic reverse-time migration , 1987 .

[8]  J. T. Kuo,et al.  Kirchhoff elastic wave migration for the case noncoincident source and receiver , 1984 .

[9]  R. Wu.  Synthetic seismograms in heterogeneous media by one-return approximation , 1996 .

[10]  Ru-Shan Wu,et al.  Scattering characteristics of elastic waves by an elastic heterogeneity , 1985 .

[11]  Paul L. Stoffa,et al.  Split-Step Fourier Migration , 1990 .

[12]  G. McMechan,et al.  Scalar reverse‐time depth migration of prestack elastic seismic data , 2001 .

[13]  M. D. Fisk,et al.  The phase screen method for vector elastic waves , 1991 .

[14]  Samuel H. Gray,et al.  Can we image beneath salt , 1996 .

[15]  T. Lay,et al.  The Excitation of Lg Waves by Explosions: A Finite-Difference Investigation , 1994 .

[16]  C. Stein,et al.  The Solid Earth: An Introduction to Global Geophysics , 1991 .

[17]  Ru-Shan Wu,et al.  Extended local Born Fourier migration method , 1999 .

[18]  Michael Fehler,et al.  GLOBALLY OPTIMIZED FOURIER FINITE-DIFFERENCE MIGRATION METHOD , 2000 .

[19]  Prestack depth migration using a hybrid pseudo‐screen propagator , 1998 .

[20]  Xiao-Bi Xie,et al.  3D Elastic Wave Modeling Using the Complex Screen Method , 1996 .

[21]  Real data results of Kirchhoff elastic wave migration , 1986 .

[22]  Biondo Biondi.  Stable wide‐angle Fourier‐finite difference downward extrapolation of 3‐D wavefields , 2001 .

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

[24]  Paul G. Richards,et al.  Quantitative Seismology: Theory and Methods , 1980 .

[25]  R. Wu,et al.  Modeling elastic wave forward propagation and reflection using the complex screen method. , 2001, The Journal of the Acoustical Society of America.

[26]  Xiao‐Bi Xie,et al.  Improve the wide angle accuracy of screen method under large contrast , 1998 .

[27]  Extraction of P- and S-waves from the vertical component of the particle velocity at the sea floor , 1995 .

[28]  R. H. Wu,et al.  Improving the Wide Angle Accuracy of the Screen Propagator For Elastic Wave Propagation , 1999 .

[29]  J. Hudson,et al.  A geometrical approach to the elastic complex screen , 1998 .

[30]  Prestack multicomponent migration , 1997 .

[31]  Ru-Shan Wu,et al.  Multiscreen backpropagator for fast 3D elastic prestack migration , 1994, Optics & Photonics.

[32]  George A. McMechan,et al.  3-D elastic prestack, reverse-time depth migration , 1994 .

[33]  Multicomponent prestack depth migration by scalar wavefield extrapolation , 2002 .