A forward model for geoacoustic inversion based on ray tracing and plane-wave reflection coefficients

2006 ◽  
pp. 241-255 ◽  
Author(s):  
Jens M. Hovem ◽  
Hefeng Dong ◽  
Xiukun Li
Keyword(s):  
Plane Wave ◽  
Ray Tracing ◽  
Wave Reflection ◽  
Forward Model ◽  
Reflection Coefficients ◽  
Geoacoustic Inversion

Fast computation of seabed spherical-wave reflection coefficients in geoacoustic inversion

2015 ◽  
Vol 138 (4) ◽  
pp. 2106-2117 ◽  
Author(s):  
Jorge E. Quijano ◽  
Stan E. Dosso ◽  
Jan Dettmer ◽  
Charles W. Holland
Keyword(s):  
Wave Reflection ◽  
Spherical Wave ◽  
Reflection Coefficients ◽  
Fast Computation ◽  
Geoacoustic Inversion

Reflection coefficients in attenuative anisotropic media

Geophysics ◽  
2009 ◽  
Vol 74 (5) ◽  
pp. WB193-WB202 ◽  
Author(s):  
Jyoti Behura ◽  
Ilya Tsvankin
Keyword(s):  
Plane Wave ◽  
Wave Reflection ◽  
Symmetry Plane ◽  
Anisotropic Media ◽  
P Wave ◽  
Substantial Contribution ◽  
Reflection Coefficients ◽  
Slowness Vector ◽  
Anisotropy Parameters ◽  
Attenuation Anisotropy

Such reservoir rocks as tar sands are characterized by significant attenuation and, in some cases, attenuation anisotropy. Most existing attenuation studies are focused on plane-wave attenuation coefficients, which determine the amplitude decay along the raypath of seismic waves. Here we study the influence of attenuation on PP- and PS-wave reflection coefficients for anisotropic media with the main emphasis on transversely isotropic models with a vertical symmetry axis (VTI). Concise analytic solutions obtained by linearizing the exact plane-wave reflection coefficients are verified by numerical modeling. To make a substantial contribution to reflection coefficients, attenuation must be strong, with the quality factor [Formula: see text] not exceeding 10. For such highly attenuative media, it is also necessary to take attenuation anisotropy into account if the magnitude of the Thomsen-styleattenuation-anisotropy parameters is relatively large. In general, the linearized reflection coefficients in attenuative media include velocity-anisotropy parameters but have almost “isotropic” dependence on attenuation. Our formalism also helps evaluate the influence of the inhomogeneity angle (the angle between the real and imaginary parts of the slowness vector) on the reflection coefficients. A nonzero inhomogeneity angle of the incident wave introduces additional terms into the PP- and PS-wave reflection coefficients, which makes conventional amplitude-variation-with-offset (AVO) analysis inadequate for strongly attenuative media. For instance, an incident P-wave with a nonzero inhomogeneity angle generates a mode-converted PS-wave at normal incidence, even if both half-spaces have a horizontal symmetry plane. The developed linearized solutions can be used in AVO inversion for highly attenuative (e.g., gas-sand and heavy-oil) reservoirs.

Reflection of elastic waves from a linear transition layer

1966 ◽  
Vol 56 (2) ◽  
pp. 511-526
Author(s):  
Ravindra N. Gupta
Keyword(s):  
Plane Wave ◽  
Material Properties ◽  
Transition Layer ◽  
Elastic Waves ◽  
Wave Reflection ◽  
Reflection Coefficients ◽  
Angle Of Incidence ◽  
Arbitrary Angle ◽  
S Wave ◽  
Incidence Plane

abstract A separation of P- and S-wave potentials is achieved for an inhomogeneous medium in which density is constant and Lame's parameters, λ and μ, are assumed to vary as λ/λ1 = μ/μ1 = (1 + bz)2 where λ1, μ1 and b are constants. The resulting equations are solved for an arbitrary angle of incidence. Plane wave reflection coefficients are obtained for the situation when the material mentioned above forms a transition layer between two homogeneous, elastic half-spaces. First and/or second-order discontinuities in material properties are permitted at the boundaries of the transition layer. Some numerical results are given.

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