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Reflector dip in terms of traveltimes squared

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Journal Articles
Petrophysics - The SPWLA Journal of Formation Evaluation and Reservoir Description 60 (02): 335–347.
Paper Number: SPWLA-2019-v60n2a10
Published: 01 April 2019
... angle of incidence of the reflected arrival is related to the relative dip, and the moveout in 3D across the individual sensors is related to the azimuthal orientation of the reflector. This information is then used to produce a 3D structural map of the reflector, which can be readily used for further...
Proceedings Papers

Paper presented at the SPWLA 59th Annual Logging Symposium, June 2–6, 2018
Paper Number: SPWLA-2018-JJJJ
... dip, and the moveout in 3D across the individual sensors is related to the azimuthal orientation of the reflector. This information is then used to produce a 3D structural map of the reflector which can be readily used for further geomodeling. This new technique addresses several shortcomings in the...
Proceedings Papers

Paper presented at the 2012 SEG Annual Meeting, November 4–9, 2012
Paper Number: SEG-2012-0507
... DSR formula valid for media with the symmetry axis normal to the dip of the reflector (DTI). The accuracy of this approximate solution is enhanced using Shanks transform to a point where the errors are extremely small for practical anisotropic values. Under this assumption, we also do not need to...
Proceedings Papers

Paper presented at the 2015 SEG Annual Meeting, October 18–23, 2015
Paper Number: SEG-2015-5807160
... non- uniqueness. We therefore must make some assumptions about the anisotropy symmetry axes. I assume that anisotropy axes are perpendicular to the dipping reflectors. This is called a dip-constrained transverse-isotropic (DTI) model (Alkhakifah and Sava, 2010). Dix-type inversion of walkaway first...
Proceedings Papers

Paper presented at the 2005 SEG Annual Meeting, November 6–11, 2005
Paper Number: SEG-2005-0116
.... Numbers around the outer circle denote azimuth (in degrees) from the reflector dip plane. The radial scale corresponds to the magnitude of hyperbolic moveout term av- eraged over azimuth . 0.02 0.04 0.06 0.08 0.1 30 210 60 240 90 270 120 300 150 330 180 0 Fig. 2: TNH, num ( marks negative and N...
Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, October 11–16, 2020
Paper Number: SEG-2020-3424784
... investigation on capability of LSRTM, to image a deep geological setting which includes steep dip reflectors, major subduction zone, was performed. Applying a finite faults and thrusts. The LSRTM process was conducted in difference modelling on the high resolution GO_3D_OBS two steps due to the memory shortage...
Proceedings Papers

Paper presented at the 2012 SEG Annual Meeting, November 4–9, 2012
Paper Number: SEG-2012-0053
...-midpoint traveltime pyramid in transversely isotropic media: Geophysics, 65, 1316 1325. Alkhalifah, T., 2000b, Prestack phase-shift migration of separate offsets: Geophysics, 65, 1179 1194. Alkhalifah, T., and S. Fomel, 2010, Source-receiver two-way wave extrapolation for prestack exploding reflector...
Proceedings Papers

Paper presented at the 2009 SEG Annual Meeting, October 25–30, 2009
Paper Number: SEG-2009-0211
.... In addition, we can use least-square fitting of any NMO approximation, which will provide a more stable and accurate result. From walkaway VSP data, virtual reflected traveltimes are created, using each receiver as a virtual horizontal reflector. Traveltimes are approximated using several three-term...
Proceedings Papers

Paper presented at the 2000 SEG Annual Meeting, August 6–11, 2000
Paper Number: SEG-2000-2229
... Summary P-wave reflection traveltimes may be used to constrain the depth scale of transversely isotropic models with a vertical symmetry axis (VTI) if the medium above the reflector is laterally heterogeneous In Part I of this work w e examined the inversion of P-wave normal-moveout (NMO...
Proceedings Papers

Paper presented at the 2015 SEG Annual Meeting, October 18–23, 2015
Paper Number: SEG-2015-5792516
... Thomsen (1988). The result of Alkhalifah and Tsvankin (1995) based on the 2D NMO equation of Tsvankin (1995) can be applied only if the symmetry axis lies in the dip plane of the reflector. Tsvankin (1997) suggested obtaining anisotropic parameter by inverting dip-dependent P-wave moveout in the vertical...
Proceedings Papers

Paper presented at the 2000 SEG Annual Meeting, August 6–11, 2000
Paper Number: SEG-2000-2225
... estimating the vertical velocity and depth scale of the model from surface data. For laterally homogeneous VTI (transversely isotropic with a vertical symmetry axis) media above the target reflector, P-wave reflection traveltimes alone are insufficient to obtain the vertical v elocityVP0 and Thomsen...
Proceedings Papers

Paper presented at the 2017 SEG International Exposition and Annual Meeting, September 24–29, 2017
Paper Number: SEG-2017-17795790
... (1956) and Taner and Koehler (1969). In horizontally layered media, for source-receiver spread-length of up to approximately a depth to the reflector, the well known hyperbolic approximation is used to describe the reflection traveltimes. Normal-moveout (NMO) velocity is the only parameter that controls...
Proceedings Papers

Paper presented at the 2011 SEG Annual Meeting, September 18–23, 2011
Paper Number: SEG-2011-3017
... conven- tional eikonal is, however, a one way traveltime map that does not reflect directly the source/receiver setup associated with our typical surface seismic reflection ex- periment. For horizontal reflectors, such travelimes in homogenous media is given by a simple hyperbolic sur- face. To include...
Proceedings Papers

Paper presented at the 2003 SEG Annual Meeting, October 26–31, 2003
Paper Number: SEG-2003-2100
... improved velocity estimate. n n 1 n 1 n n 1 n n h (h 39=Bh Figure 6: Moreni velocity grid (courtesy of IFP). Examples We begin with a simple laterally-varying TI velocity model, in which the strata dip to the right at , overlaying a dipping reflector R (Figure 1). The auxiliary horizon M is immersed...
Proceedings Papers

Paper presented at the 2013 SEG Annual Meeting, September 22–27, 2013
Paper Number: SEG-2013-0559
... dip constraint is structural and does not constrain the position of the seismic reflectors. A shallow channel example Migration velocity analysis usually fails to identify velocity variations caused by very shallow channels (Figures 1 and 4) because RMO picks are sparse in shallow parts and resolution...
Proceedings Papers

Paper presented at the 1998 SEG Annual Meeting, September 13–18, 1998
Paper Number: SEG-1998-1855
... used to help iden- tify the phase of the seismic wavelet associated with each reflector. For the correct velocity model the central event in the gather will appear flat across all offsets because of the effective subtraction of the ray-trace moveout. Otherwise, the traveltime residuals for non-zero...
Proceedings Papers

Paper presented at the 2017 SEG International Exposition and Annual Meeting, September 24–29, 2017
Paper Number: SEG-2017-17657381
... the acceptable error limit through successive iterations of inversion and parameter update, which result in sufficient flattening of the reflected events in the common image gathers (CIG's). This is a powerful and stable methodology to handle large tilts (? = 60°) of the steeply dipping reflectors in...
Proceedings Papers

Paper presented at the 1988 SEG Annual Meeting, October 30–November 3, 1988
Paper Number: SEG-1988-1061
... reflector depth. Yet progress in velocity estimation has been slow and tortuous. In 1955 Oix developed a procedure for estimating velocity from seismic traveltimes when the geology consists of flat homogeneous beds that are parallel to one another; each bed is of uniform thickness. It was not until 1974...
Proceedings Papers

Paper presented at the 2018 SEG International Exposition and Annual Meeting, October 14–19, 2018
Paper Number: SEG-2018-2987198
... when it comes to complex subsurface structure such as steeply dipping reflectors, overthrust strata and so on. However, due to irregular illumination and acquisition footprint, RTM can t generate amplitude preserved imaging and artifacts exist in migration section. The concept of inversion was...
Proceedings Papers

Paper presented at the 2017 SEG International Exposition and Annual Meeting, September 24–29, 2017
Paper Number: SEG-2017-17680865
... popular least squares reverse time migration, has the advantage of being fast enough to be applied in a production environment, and flexible enough to be applied without data regularization. This last characteristic makes it a good candidate to understand benefits in terms of footprint acquisition and...

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