Dip-moveout processing by Fourier transform in anisotropic media

Conference · Thu Dec 01 04:00:00 EST 1994

OSTI ID:10128838

Anderson, J ^[1]; Tsvankin, I ^[2]

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1. Mobil Oil Co., Dallas, TX (United States)
2. Colorado School of Mines, Golden, CO (United States). Dept. of Geophysics

Conventional dip-moveout (DMO) processing is designed for isotropic media and cannot handle angle-dependent velocity. The authors show that Hale`s isotropic DMO algorithm remains valid for elliptical anisotropy but may lead to serious errors for non-elliptical transversely isotropic models, even if velocity anisotropy is moderate. Here, they present an extension of Hale`s constant-velocity DMO method to anisotropic media. The DMO operator, to be applied to normal-moveout (NMO) corrected data, is based on the analytic expression for NMO velocity for dipping reflectors given by Tsvankin (1995a). Since the anisotropic DMO depends on the elastic parameters of the medium, it should be preceded by an inversion procedure designed to obtain the NMO velocity as a function of ray parameter. Another complication introduced by anisotropy is the influence of nonhyperbolic moveout not accounted for in the DMO operator. However, for spreads typical in conventional acquisition design, deviations from hyperbolic moveout for P-waves are not significant. Impulse responses and synthetic examples for typical transversely isotropic models with a vertical symmetry axis (VTI) demonstrate the accuracy and efficiency of this DMO technique. Once the inversion step has been completed, the NMO-DMO sequence does not take any more computing time than that for the generic Hale`s method in isotropic media. Their anisotropic DMO operator is not limited to VTI media; it can be applied in the same fashion in symmetry planes of more complicated models such as orthorhombic.

• Research Organization: Colorado School of Mines, Golden, CO (United States). Center for Wave Phenomena
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: FG02-89ER14079
• OSTI ID: 10128838
• Report Number(s): DOE/ER/14079--35; CWP--146P; CONF-940004--1; ON: DE95007668; BR: KC0403010
• Country of Publication: United States
• Language: English

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