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Effect of migration on plotted reflector locations

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Proceedings Papers

Paper presented at the 2001 SEG Annual Meeting, September 9–14, 2001
Paper Number: SEG-2001-0877
... sections. The true reflector positions need not be guessed or estimated: they follow naturally from the migration results. Instead, the backprojection operator incorporates reflector movement and ray-bending effects. Algorithm The lack of flatness of an event across different offsets on a depth migrated...
Proceedings Papers

Paper presented at the 1994 SEG Annual Meeting, October 23–28, 1994
Paper Number: SEG-1994-0672
... based on the point reflector is applied. The stack of these traces with appropriate creates a trace that is part of the prestack migrated section. Evaluation of the migrated equivalent offset gathers also yield information on the source of noise, such as multiples or shot aliasing, that effect...
Proceedings Papers

Paper presented at the 1998 SEG Annual Meeting, September 13–18, 1998
Paper Number: SEG-1998-1297
... below salt. We show for this model, that depth resolution due to velocity error drops by roughly a factor of three as one moves from sediments outside salt to sediments below salt. Second, we investigate the effect of salt mispositioning on the migrated image, particularly below the lateral edge...
Proceedings Papers

Paper presented at the 2014 SEG Annual Meeting, October 26–31, 2014
Paper Number: SEG-2014-1359
... representation velocity uncertainty travel time upstream oil & gas absolute depth migration imaging planetary science likelihood function malcolm earth resource laboratory artificial intelligence Effect of velocity uncertainty on migrated reflectors Oleg V. Poliannikov and Alison E. Malcolm...
Proceedings Papers

Paper presented at the 1990 SEG Annual Meeting, September 23–27, 1990
Paper Number: SEG-1990-1271
... velocity is a fundamental step in the process of imaging seismic data. To focus properly the reflectors at the original positions, depth migration needs a velocity function that predicts accu- rately the propagation effects of velocity on the recorded reflections. Interval velocity cannot be estimated...
Proceedings Papers

Paper presented at the 2004 SEG Annual Meeting, October 10–15, 2004
Paper Number: SEG-2004-1313
.... These features provide a better separation of the primary reflection energy, allowing a more effective attenuation of the multiple-energy. References Bancroft, J. C., Geiger, H. D., and Margrave, G. F., 1998, The equivalent offset method of prestack time migration: Geophysics, 63,. 2042-2053. Bradshaw, A. and Ng...
Proceedings Papers

Paper presented at the 2016 SEG International Exposition and Annual Meeting, October 16–21, 2016
Paper Number: SEG-2016-13820365
.... Figure 2b: Fresnel angle plot with increase of travel time, for various reflector dips. Examples Followings are two synthetic and one real data examples to show the accuracy of our method. We applied dip field picked from depth migrated stack and the angle domain Fresnel zone derived here to separate...
Proceedings Papers

Paper presented at the 1992 SEG Annual Meeting, October 25–29, 1992
Paper Number: SEG-1992-0885
.... Different types of noise can be handled with this technique as long as the moveout of the desired signal is distinquishable from the noise. One undesirable side-effect of viewing prestack migrated data is the wavelet stretch associated with the imaging principle used in most migration algorithms...
Proceedings Papers

Paper presented at the 2011 SEG Annual Meeting, September 18–23, 2011
Paper Number: SEG-2011-3908
... to be con- structed at sparse locations throughout an image, and they need to be constructed near the center of coherent reflectors that have simple structure. However, picking CIP locations by hand is a tedious and time-consuming process. The method described in this paper is both fast and effective...
Proceedings Papers

Paper presented at the 1983 SEG Annual Meeting, September 11–15, 1983
Paper Number: SEG-1983-0393
... ABSTRACT No preview is available for this paper. migration residual migration aperture accuracy operator reflector upstream oil & gas frequency effective dip wavefunction stolt migration salvador equation dipldegreesl algorithm reservoir characterization unmigrated...
Proceedings Papers

Paper presented at the 1987 SEG Annual Meeting, October 11–15, 1987
Paper Number: SEG-1987-0839
... of tomography. Modeling demonstrates that the iterative application of tomograjhy and migration is able to correct &-problems 0; an inaccurate starting model. Edrre effects can be identifipd and corrected by- constmints~ Resolution analysis demonstrates that the velocity-reflector depth ambiguity should...
Proceedings Papers

Paper presented at the 2008 SEG Annual Meeting, November 9–14, 2008
Paper Number: SEG-2008-1570
... is therefore sufficient in a survey planning mode to deduce dip and azimuth of the illuminated reflectors at any location in space. The shorter ISR is, due to a larger opening angle (Figure 1), the poorer the resolution (pulse stretching effect). The overall spatial coverage of ISR, combined with a pulse...
Proceedings Papers

Paper presented at the SPWLA 59th Annual Logging Symposium, June 2–6, 2018
Paper Number: SPWLA-2018-JJJJ
... an abrupt change in the relative dip of reflectors above and below the possible fault plane using the 3D STC and ray tracing. Dip patterns from both wells showed a drag effect around the offset well tops, further confirming the presence of a fault. A comparison of the acquired borehole images pinpointed...
Proceedings Papers

Paper presented at the 2013 SEG Annual Meeting, September 22–27, 2013
Paper Number: SEG-2013-1017
... of primary reflector is gentle, SF migration can not do much with the multiple reflector. Although only a demultiple case is explained, in practice, SF migration is probably more effective in migration swing suppression. It can also potentially remove refraction waves, head waves, converted waves, and etc...
Proceedings Papers

Paper presented at the 2004 SEG Annual Meeting, October 10–15, 2004
Paper Number: SEG-2004-2427
... with an opening between 0o and 90o. When multiple reflectors are present, we can notice the V s opening gradually. The same holds true for angle-domain common image gathers (ADCIGs; Biondi, 2003), after prestack depth migration. In the depth- Figure 1: FEAVO effects, midpoint-offset space, before migration Figure...
Proceedings Papers

Paper presented at the 1989 SEG Annual Meeting, October 29–November 2, 1989
Paper Number: SEG-1989-1225
... the closer flat reflector illuminates the anomaly at higher opening angles. The plots still show some artifacts, most noticeably the two arms extending from the anomaly downward. They can be explained as end effects due to limited shot coverage.. Depth points in the center of the survey are illuminated...
Proceedings Papers

Paper presented at the 2005 SEG Annual Meeting, November 6–11, 2005
Paper Number: SEG-2005-2017
... than common offset images. CRAM is able to combine both of these features in a cost-effective way. CRAM images can be QC''d using illumination plots as a function of dip angle. reflection angle salt face ray reference list upstream oil & gas image point imaging mike rainwater ted...
Proceedings Papers

Paper presented at the 2009 SEG Annual Meeting, October 25–30, 2009
Paper Number: SEG-2009-2924
... geometries. Processing of both the exhaustive and decimated datasets with various algorithms allows us to examine the effect of spatial sampling on footprint, and also to observe how algorithmic differences influence the footprint artifacts. In this paper we focus on footprint after prestack migration...
Proceedings Papers

Paper presented at the 2000 SEG Annual Meeting, August 6–11, 2000
Paper Number: SEG-2000-1560
... geometry, velocity structure, imaging constraints, and preprocessing effects. 3-D VSP MIGRATION IMAGING The 3-D VSP seismic acquisition geometry is often characterized by irregular source distribution at the surface (in some cases, circular), and irregular receiver locations in a deviated borehole...
Proceedings Papers

Paper presented at the 1992 SEG Annual Meeting, October 25–29, 1992
Paper Number: SEG-1992-1034
... in 15-degree increments. The seismo- grams contain 10 offsets, ranging from 100 m to 1900 m in 200 m increments. After prestack migration with the constant velocity. c = 1.5 km/s, one of the CDP gathers is plotted in Figure 2. Be- cause the background velocity is lower than the true velocity, all event...

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