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Frequency-wavenumber migration in practice

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Proceedings Papers

Paper presented at the 2018 SEG International Exposition and Annual Meeting, October 14–19, 2018
Paper Number: SEG-2018-2995921
... for the separation of the two components is scattering angle filtering based upon equation 6 (Wu and Alkhalifah, 2015, 2017; Yao et al., 2018). As can be seen from equation 6, for a given frequency and velocity, the tomographic component has smaller wavenumbers than the migration component. This is illustrated...
Proceedings Papers

Paper presented at the 2002 SEG Annual Meeting, October 6–11, 2002
Paper Number: SEG-2002-1152
... Summary 3-D prestack migration of constant-offset data can be formulated in the frequency-wavenumber domain as a stationary phase approximation to equivalent Kirchhoff expressions. This formulation constitutes a proof of Dubrulle''s (1983) heuristic algorithm. Numerical implementations are 3-D...
Proceedings Papers

Paper presented at the 2009 SEG Annual Meeting, October 25–30, 2009
Paper Number: SEG-2009-2383
... For constant-velocity demigration/remigration the DSR process is equivalent to the application of a mutli-dimensional shaping operator, applied after migration. Here we extend the spectral shaping concept, to modify not just the frequency (temporal), but also the wavenumber (spatial) spectrum of the data...
Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, September 15–20, 2019
Paper Number: SEG-2019-3200038
... laplacian filter exxonmobil upstream research company traditional laplacian filter dip-guided laplacian image filter seg international exposition low-wavenumber noise noise artifact reservoir characterization effectiveness annual meeting equation migration reverse-time migration operator...
Proceedings Papers

Paper presented at the 2005 SEG Annual Meeting, November 6–11, 2005
Paper Number: SEG-2005-1846
... table frequency dataset phase shift spmi 2 application seg houston 2005 algorithm evanescent equation migration wavenumber extrapolation compactly upstream oil & gas depth migration reservoir characterization explicit depth migration Optimizing explicit depth migration...
Proceedings Papers

Paper presented at the 2001 SEG Annual Meeting, September 9–14, 2001
Paper Number: SEG-2001-0296
... inaccurate, amplitude responses. The amplitude problem is related to the fact that downward continuation migration is the ad-joint of upward-continuation modeling, but it is a poor approximation of its inverse. We derive the weighting operators, diagonal in the frequency-wavenumber domain, that makes...
Proceedings Papers

Paper presented at the 2010 SEG Annual Meeting, October 17–22, 2010
Paper Number: SEG-2010-3210
... by a phase shift of the form eikz z , where z is depth and kz is vertical wavenumber, has been widely used previously as a basis for downwardcontinuation modeling and migration methods (e.g., Gazdag, 1978). RITE operators for scalar acoustic waves The square-root, exponential, and cosine...
Proceedings Papers

Paper presented at the 2017 SEG International Exposition and Annual Meeting, September 24–29, 2017
Paper Number: SEG-2017-17731403
... gradient of reflection data. As shown by Mora (1989), reflection data produce two different components in the FWI gradient: the high- wavenumber component, also known as the migration term, and the low-wavenumber component, also known as the tomographic term or rabbit ears (Figure 1). This tomographic...
Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, September 15–20, 2019
Paper Number: SEG-2019-3216654
... smoothing operator to migration velocity model, which is followed by a standard RTM. The proposed imaging strategy suppresses the diving-wave imaging artifacts as well as the low-frequency noises. Meanwhile, it keeps the ability to imaging structures that are with high dip angle without any additional...
Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, October 11–16, 2020
Paper Number: SEG-2020-3427923
... Seismic amplitudes can be biased by uneven illumination in the presence of a complex overburden. Iterative Least-Squares Migration (LSM) can reduce the amplitude bias and improve the resolution of the images. We introduce a robust and practical iterative least-squares migration for the inversion...
Proceedings Papers

Paper presented at the 2018 SEG International Exposition and Annual Meeting, October 14–19, 2018
Paper Number: SEG-2018-2995236
... became a practical method for the inverting the subsurface velocity. Even many studies of FWI, recovering the full spatial-frequency (wavenumber) of the model is difficult because of the insufficient low frequency component and limitation of the offset range. These limitations make the FWI invert only...
Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, September 15–20, 2019
Paper Number: SEG-2019-3215798
... ) produced by migration and FWI as a dot-product of slowness vectors associated to two local-plane waves. Thus the low instantaneous wavenumbers K are obtained through low frequency and wide scattering angle. In Chavent et al. (1994a), and Bunks et al. (1995) the low wavenumbers are obtained first, from...
Proceedings Papers

Paper presented at the 1990 SEG Annual Meeting, September 23–27, 1990
Paper Number: SEG-1990-1301
... that this accuracy is rarely achieved in practice. Over the wide rauge of normalized frequencies likely to be encountered in practice, stable explicit extrapolators outperform implicit ones. REFERENCES Blat ui&re, G., Debe e, H. W. J., Wapenaar, C. P. A., 8 an Berkhout, A. 3 ., 1989, 3D table-driven migration...
Proceedings Papers

Paper presented at the 2015 SEG Annual Meeting, October 18–23, 2015
Paper Number: SEG-2015-5829692
... Summary I describe a new two-way wave equation migration that combines the efficiency of one-way wave equation migration with the imaging capability of reverse time migration. This approach extrapolates the wavefield in the frequency-wavenumber domain along the depth axis. The key...
Proceedings Papers

Paper presented at the 2016 SEG International Exposition and Annual Meeting, October 16–21, 2016
Paper Number: SEG-2016-13872562
... associated with shallow gas pockets, and enabled us to mitigate imaging distortions at the target intervals. In addition, FWI uncovered a scale of sub-surface information typically unavailable on standard migrated sections, in effect filling-in the low wavenumbers that correspond to frequencies below...
Proceedings Papers

Paper presented at the 2018 SEG International Exposition and Annual Meeting, October 14–19, 2018
Paper Number: SEG-2018-2996390
... for one-way wave equation migration (though exactly how to smooth and damp are serious practical issues). Those methods naturally work one (or a few) (1) (4) (2) (3) 10.1190/segam2018-2996390.1 Page 4372 © 2018 SEG SEG International Exposition and 88th Annual Meeting Deconvolution ISIC frequencies...
Proceedings Papers

Paper presented at the 2009 SEG Annual Meeting, October 25–30, 2009
Paper Number: SEG-2009-2552
... size. )2( 22 2 11 ]1cos t kFtv v Then, we compute phase velocity as a function of wavenumber by dividing temporal frequency by the magnitude of the wavenumber vector. )3( 22 2 11 ]1cos )( kt kFtv kv phase v v Written this way, we find the numerical phase velocity of an acoustic wave...
Proceedings Papers

Paper presented at the 1995 SEG Annual Meeting, October 8–13, 1995
Paper Number: SEG-1995-1377
... ABSTRACT No preview is available for this paper. geophysics amplitude time migration diffraction prestack time migration reservoir characterization ekren frequency-wavenumber constant-offset migration migrated data nmo correction equation time migration algorithm data...
Proceedings Papers

Paper presented at the 2008 SEG Annual Meeting, November 9–14, 2008
Paper Number: SEG-2008-2381
... in the frequency domain (commonly called ''Shot profile wave equation migration''), or ''two-way'' 3D finite difference modeling (commonly called ''Reverse time migration''). When analyzing the sampling issues, we should consider both those within a single supershot, in addition to the related issue...
Proceedings Papers

Paper presented at the 2007 SEG Annual Meeting, September 23–28, 2007
Paper Number: SEG-2007-2240
..., frequency and wavenumber dependent, phase shift. The Gabor transform is implemented as a windowed discrete Fourier transform where the windows are confined to form a partition of unity (POU), meaning that they sum to one. For efficiency, an adaptive partitioning scheme that relates window width...

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