STANFORD EXPLORATION PROJECT

Gabriel Alvarez, Elkin Arroyo, Brad Artman, James Berryman, Biondo Biondi, Liliana Borcea, Morgan Brown, Robert Clapp, William Curry, Sergey Fomel, Antoine Guitton, Seth Haines, E. Herkenhoff, Andrey Karpushin, Jesse Lomask, George Papanicolaou, Marie Prucha, Daniel Rosales, Paul Sava, Guojian Shan, Chrysoula Tsogka, Alejandro Valenciano, Eric Verschuur, and Ioan Vlad

Number 111, April 2002

2002

Preface

The electronic version of this report makes the included programs and applications available to the reader. The markings [ER], [CR], and [NR], are promises by the author about the reproducibility of each figure result.

Reproducibility is a way of organizing computational research, which allows both the author and the reader of a publication to verify the reported results at a later time. Reproducibility facilitates the transfer of knowledge within SEP and between SEP and its sponsors.

ER

denotes Easily Reproducible and are the results of a processing described in the paper. The author claims that you can reproduce such a figure from the programs, parameters, and makefiles included in the electronic document. The data must either be included in the electronic distribution, or be easily available (e.g. SEG-EAGE data sets) to SEP and non-SEP researchers. The data may also be available in the SEP data library, which can be viewed at http://sepwww.stanford.edu/public/docs/sepdatalib/toc_html/. We assume you have a UNIX workstation with Fortran, Fortran90, C, X-Windows system and the software downloadable from our website (SEP makerules, SEPlib, and, to properly reproduce the documents, the SEP latex package), or other free software such as SU. Before the publication of the electronic document, someone other than the author tests the author's claim by destroying and rebuilding all ER figures. Some ER figures may not be reproducible by outsiders because they depend on data sets that are too large to distribute, or data that we do not have permission to redistribute but are in the SEP data library.

CR

denotes Conditional Reproducibility. The author certifies that the commands are in place to reproduce the figure if certain resources are available. SEP staff have only attempted to make sure that the makefile rules exist and the source codes referenced are provided. The primary reasons for the CR designation is that the processing requires 20 minutes or more, or commercial packages such as Matlab or Mathematica.

M

denotes a figure that may be viewed as a movie in the web version of the report. A movie may be either ER or CR.

NR

denotes Non-Reproducible. This class of figure is considered non-reproducible. SEP discourages authors from flagging their figures as NR except for artist drawings, scannings, etc.

Our testing is currently limited to IRIX 6.5 and LINUX 2.1 (using the Portland Group Fortran90 compiler), but the code should be portable to other architectures. Reader's suggestions are welcome. For more information on reproducing SEP's electronic documents, please visit
<http://sepwww.stanford.edu/redoc/>.

Jon Claerbout, Biondo Biondi, Robert Clapp, and Marie Prucha

SEP-111 -- TABLE OF CONTENTS

Migration

Subsalt event regularization with steering filters (ps.gz 3346K) (pdf 1176K) (src 16205K)
Prucha M. L. and Biondi B. L.
Shot-profile migration of multiple reflections (ps.gz 0K) (pdf 0K)
Guitton A.
Least-squares joint imaging of primaries and multiples (ps.gz 0K) (pdf 0K)
Brown M.
Converted wave dip moveout (ps.gz 0K) (pdf 0K)
Rosales D.
Converted wave azimuth moveout (ps.gz 0K) (pdf 0K)
Rosales D. and Biondi B.
Multidimensional imaging condition for shot profile migration (ps.gz 0K) (pdf 0K)
Valenciano A. A., Biondi B., and Guitton A.

Velocity

Wave-equation migration velocity analysis beyond the Born approximation (ps.gz 0K) (pdf 0K)
Sava P. and Fomel S.
Matching dips in velocity estimation (ps.gz 0K) (pdf 0K)
Clapp R. G.
Velocity estimation for seismic data exhibiting focusing-effect AVO (ps.gz 0K) (pdf 0K)
Vlad I. and Biondi B.

Time reverse imaging

Prestack imaging of overturned and prismatic reflections by reverse time migration (ps.gz 0K) (pdf 0K)
Biondi B.
Statistical stability and time-reversal imaging in random media (ps.gz 0K) (pdf 0K)
Berryman J. G., Borcea L., Papanicolaou G. C., and Tsogka C.
Reverse time migration in midpoint-offset coordinates (ps.gz 0K) (pdf 0K)
Biondi B.

Noise removal

Adaptive subtraction of multiples with the 1#1-norm (ps.gz 0K) (pdf 0K)
Guitton A. and Verschuur E.
A hybrid adaptive subtraction method (ps.gz 0K) (pdf 0K)
Guitton A.
Removal of coherent noise from electroseismic data (ps.gz 0K) (pdf 0K)
Haines S. and Guitton A.
Theoretical aspects of noise attenuation (ps.gz 0K) (pdf 0K)
Guitton A.
Removing velocity stack artifacts (ps.gz 0K) (pdf 0K)
Karpushin A.

Modeling and migration computational issues

Reference velocity selection by a generalized Lloyd method (ps.gz 0K) (pdf 0K)
Clapp R. G.
One-way wave equation absorbing boundary condition (ps.gz 0K) (pdf 0K)
Shan G.
Speeding up wave equation migration (ps.gz 0K) (pdf 0K)
Clapp R. G.
Finite-difference 2#2-x migration of unregularized seismic data (ps.gz 0K) (pdf 0K)
Vlad I.

Amplitudes and rock properties

Effect of velocity uncertainty on amplitude information (ps.gz 0K) (pdf 0K)
Clapp R. G.
An extension of poroelastic analysis to double-porosity materials: (ps.gz 0K) (pdf 0K)
Berryman J. G.
Amplitude inversion for three reflectivities (ps.gz 0K) (pdf 0K)
Prucha M. L. and Herkenhoff E. F.

Filtering and inversion

Fault contours from seismic (ps.gz 0K) (pdf 0K)
Lomask J.
Toward subsurface illumination-based seismic survey design (ps.gz 0K) (pdf 0K)
Alvarez G.
Non-stationary, multi-scale prediction-error filters and irregularly sampled data (ps.gz 0K) (pdf 0K)
Curry W.
Madagascar satellite data: an inversion test case (ps.gz 0K) (pdf 0K)
Lomask J.
Implementing non-stationary filtering in time and in (ps.gz 0K) (pdf 0K)
Alvarez G.

Passive imaging

A return to passive seismic imaging (ps.gz 0K) (pdf 0K)
Artman B.
Is 2D possible? (ps.gz 0K) (pdf 0K)
Artman B.
Coherent noise in the passive imaging experiment (ps.gz 0K) (pdf 0K)
Artman B.

Computing

WEI: Wave-Equation Imaging Library (ps.gz 0K) (pdf 0K)
Sava P. and Clapp R. G.
Displaying seismic data with VTK (ps.gz 0K) (pdf 0K)
Arroyo E. R. and Clapp R. G.
Cluster building and running at SEP (ps.gz 0K) (pdf 0K)
Clapp R. G. and Sava P.

 

Subsalt event regularization with steering filters

Marie L. Prucha and Biondo L. Biondi

ABSTRACT

The difficulties of imaging beneath salt bodies where illumination is poor are well known. In this paper, we present an angle-domain least-squares inversion scheme that regularizes the seismic image, tending to smooth along specified dips. This smoothing is accomplished using steering filters. We show the results of using the regularized inversion with smoothing along the angle axis and along both the angle and common midpoint axes. Additionally, the ramifications of specifying incorrect dips to smooth along will be examined. The results show that this regularized least-squares inversion does produce a cleaner, more continuous result under salt bodies. The inversion will reject incorrectly chosen dips used for the regularization.