MODELING OF THE S-WAVE SPLITTING IN TTI MEDIA USING HIGH-ORDER ROTATED STAGGERED GRID SCHEME
LI Min1,2, LIU Yang1,2
1. State Key Lab of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China;
2. CNPC Key Lab of Geophysical Prospecting, China University of Petroleum, Beijing 102249, China
Abstract：A high-order rotated staggered grid scheme (RSG) has been implemented to simulate the shear-wave splitting in tilted transversely isotropic (TTI) media. The high-order RSG can simulate wave propagation in media that contain high-contrast discontinuities like cracks more precisely than the standard staggered grid scheme (SSG) by avoiding the unstableness of the staggered grid scheme (SSG). The authors conducted a study of zero-offset S-wave splitting with the high-order RSG. The S-wave splitting study was mainly focused on fractured media which, on the scale of seismic wavelength, could be regarded as transversely isotropic (TI) media. The results of numerical modeling show that the high-order RSG scheme can be used to simulate waves' propagation in general anisotropic media. The perfect matched layer (PML) absorbing boundary condition combined with the high order RSG scheme can well attenuate reflections from the artificial boundary. The S-wave splitting is mainly affected by the angle between polarization direction of incoming wave and strike of the TTI media, and the energy of fast and slow shear waves is also associated with this angle. The dipping angle of TTI media may affect time lag between the fast and slow waves, which may result in variation of arrival time of waves from the same interface. Thus, the analysis of energy distribution of the fast and slow waves and the variation of arrival time may help detect the strike and dipping angle of the fracture. Besides, when propagating in the media that contain more than one layer of TTI media, the S-wave splitting will occur more than once.
李敏, 刘洋. 高阶旋转交错网格有限差分方法模拟TTI介质中横波分裂[J]. 物探与化探, 2012, 36(6): 934-940.
LI Min, LIU Yang. MODELING OF THE S-WAVE SPLITTING IN TTI MEDIA USING HIGH-ORDER ROTATED STAGGERED GRID SCHEME. Geophysical and Geochemical Exploration, 2012, 36(6): 934-940.
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