Quasi‐shear wave ray tracing by wavefront construction in 3‐D, anisotropic media

2004 ◽  
Author(s):  
Hung‐Liang Lai ◽  
Richard L. Gibson ◽  
Kyoung‐Jin Lee
Keyword(s):  
Ray Tracing ◽  
Shear Wave ◽  
Anisotropic Media ◽  
Wave Ray

Quasi-shear wave ray tracing by wavefront construction in 3-D, anisotropic media

2009 ◽  
Vol 69 (2) ◽  
pp. 82-95 ◽  
Author(s):  
Hung-Liang Lai ◽  
Richard L. Gibson ◽  
Kyoung-Jin Lee
Keyword(s):  
Ray Tracing ◽  
Shear Wave ◽  
Anisotropic Media ◽  
Wave Ray

scholarly journals Shear‐wave reflection moveout for azimuthally anisotropic media

1999 ◽  
Author(s):  
AbdulFattah Al‐Dajani ◽  
Nafi Toksöz
Keyword(s):  
Shear Wave ◽  
Wave Reflection ◽  
Anisotropic Media

Ray Tracing in Layered Anisotropic Media

1991 ◽  
Author(s):  
J. Costa ◽  
M. Schoenberg ◽  
D. Miller
Keyword(s):  
Ray Tracing ◽  
Anisotropic Media

An efficient ray-tracing method and its application to Gaussian beam migration in complex multilayered anisotropic media

Geophysics ◽  
2018 ◽  
Vol 83 (5) ◽  
pp. T281-T289 ◽  
Author(s):  
Qianru Xu ◽  
Weijian Mao
Keyword(s):  
Gaussian Beam ◽  
Ray Tracing ◽  
Initial Conditions ◽  
Anisotropic Media ◽  
Memory Storage ◽  
Ray Tracing Method ◽  
Embedded Discontinuities ◽  
Model Parameterization ◽  
Gaussian Beam Migration ◽  
Tracing Method

We have developed a fast ray-tracing method for multiple layered inhomogeneous anisotropic media, based on the generalized Snell’s law. Realistic geologic structures continuously varying with embedded discontinuities are parameterized by adopting cubic B-splines with nonuniformly spaced nodes. Because the anisotropic characteristic is often closely related to the interface configuration, this model parameterization scheme containing the natural inclination of the corresponding layer is particularly suitable for tilted transverse isotropic models whose symmetry axis is generally perpendicular to the direction of the layers. With this model parameterization, the first- and second-order spatial derivatives of the velocity within the interfaces can be effectively obtained, which facilitates the amplitude computation in dynamic ray tracing. By using complex initial conditions for the dynamic ray system and taking the multipath effect into consideration, our method is applicable to Gaussian beam migration. Numerical experiments of our method have been used to verify its effectiveness, practicability, and efficiency in memory storage and computation.

scholarly journals Transformation to zero offset in transversely isotropic media

Geophysics ◽  
1996 ◽  
Vol 61 (4) ◽  
pp. 947-963 ◽  
Author(s):  
Tariq Alkhalifah
Keyword(s):  
Ray Tracing ◽  
Impulse Response ◽  
Homogeneous Medium ◽  
Anisotropy Parameter ◽  
Transversely Isotropic ◽  
Anisotropic Media ◽  
Amplitude Distribution ◽  
Isotropic Media ◽  
Zero Offset ◽  
Vertical Inhomogeneity

Nearly all dip‐moveout correction (DMO) implementations to date assume isotropic homogeneous media. Usually, this has been acceptable considering the tremendous cost savings of homogeneous isotropic DMO and considering the difficulty of obtaining the anisotropy parameters required for effective implementation. In the presence of typical anisotropy, however, ignoring the anisotropy can yield inadequate results. Since anisotropy may introduce large deviations from hyperbolic moveout, accurate transformation to zero‐offset in anisotropic media should address such nonhyperbolic moveout behavior of reflections. Artley and Hale’s v(z) ray‐tracing‐based DMO, developed for isotropic media, provides an attractive approach to treating such problems. By using a ray‐tracing procedure crafted for anisotropic media, I modify some aspects of their DMO so that it can work for v(z) anisotropic media. DMO impulse responses in typical transversely isotropic (TI) models (such as those associated with shales) deviate substantially from the familiar elliptical shape associated with responses in homogeneous isotropic media (to the extent that triplications arise even where the medium is homogeneous). Such deviations can exceed those caused by vertical inhomogeneity, thus emphasizing the importance of taking anisotropy into account in DMO processing. For isotropic or elliptically anisotropic media, the impulse response is an ellipse; but as the key anisotropy parameter η varies, the shape of the response differs substantially from elliptical. For typical η > 0, the impulse response in TI media tends to broaden compared to the response in an isotropic homogeneous medium, a behavior opposite to that encountered in typical v(z) isotropic media, where the response tends to be squeezed. Furthermore, the amplitude distribution along the DMO operator differs significantly from that for isotropic media. Application of this anisotropic DMO to data from offshore Africa resulted in a considerably better alignment of reflections from horizontal and dipping reflectors in common‐midpoint gather than that obtained using an isotropic DMO. Even the presence of vertical inhomogeneity in this medium could not eliminate the importance of considering the shale‐induced anisotropy.

Sign in / Sign up

Export Citation Format

Share Document