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本文在考虑油藏内流体影响的基础上,进一步讨论了裂缝诱导各向异性的极化角和方位角的影响,对裂缝诱导TTI(tilted transverse isotropy)双孔隙介质模型进行了研究.在裂缝诱导HTI(horizontal transverse isotropy)双孔隙介质理论的基础上,用Bond变换推导了裂缝诱导TTI双孔隙介质的柔度系数矩阵和耗散系数矩阵,从而建立了介质的一阶速度应力方程.采用交错网格高阶有限差分法及PML边界条件,对xoz平面内的2.5维矢量波动方程进行了数值模拟.结果表明,裂缝的极化角和方位角的存在都会导致横波分裂,而在双层裂缝诱导TTI双孔隙介质模型的分界面上,又会产生转换波的分裂和横波的再分裂现象,这就增加了波场的复杂性,从而为进一步研究实际地球介质的地震波场传播特征奠定了基础.
In this paper, based on the influence of fluid in reservoirs, the influence of polarization angle and azimuth of crack-induced anisotropy is further discussed, and the dual-gap medium model of TTI (tilted transverse isotropy) is studied. HTI (horizontal transverse isotropy) theory, the first-order velocity stress equation of media was established by Bond transformation, which was used to derive the matrix of ductility coefficient and dissipation coefficient of fracture- The numerical simulation of the 2.5-D vector wave equation in the xoz plane is carried out by using the lattice higher-order finite difference method and the PML boundary conditions. The results show that the existence of the polarization angle and the azimuth angle of the fracture will lead to the shear wave splitting, The splitting of the converted wave and the re-splitting of the transverse wave will occur on the interface of the TTI dual-porosity media model, which increases the complexity of the wave field and lays the foundation for further study on the propagation characteristics of the seismic wave field in the real earth medium.