| 摘要: |
| 基于Biot理论,给出了三维双相各向异性介质应力-速度弹性波方程交错网格任意偶阶精度有限差分解法，并 对三维双相各向异性(TIH)介质中弹性波场进行了模拟。结果表明，弹性波在三维双相各向异性介质中传播时存在 快纵波qPi、快横波qS!、慢横波qSz和慢纵波qP2，并清楚地观测到了横波分裂、横波分裂盲点、波面三分叉等特殊现 象。快纵波在固相和流相中的相位相同;而慢纵波在固相和流相中的相位相反，即慢纵波在流相中振幅大，而在固 相中的振幅较小。另外，三维双相各向异性介质中弹性波场的快纵波和快横波的耦合关系、波的类型、能量分布和 相位等都是在三维空间中变化的。 |
| 关键词: 三维双相各向异性介质 弹性波场 交错网格 高阶有限差分 |
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| A staggered-grid high-order finite difference method for modeling elastic wave equation in 3-D dual-phase anisotropic media |
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PEI Zheng-lin
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(Key Laboratory of Geophysical Exploration of China National Petroleum Corporation in China University of Petroleum , Beijing 100083, China )
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| Abstract: |
| A staggered-grid arbitrary even-order accurate finite difference solution of one-order stress-velocity elastic wave equation in 3-D dual-phase anisotropic media was presented based upon Biot's theory. And 3-D numerical modeling for the elastic wave-fields in dual-phase TIH media was implemented by the method. The results show that there exist the fast P wave (qPi)，fast S wave (qSi), slow S wave(q§2) and slow P wave(qP2) in 3-D dual-phase anisotropic media during the piopagation of elastic wave . And the special phencmena such as the S wave splitting, the blind points of the S wave splitting and wavefront triplication are clearly observed. The phase of the fast P wave is same in both solid phase and liquid phase, and that of the slow P wave is reverse. The amplitude of the slow P wave in liquid phase is bi踩er than that in solid phase. In addition, the coupled relation of the qPi and qSi, wave types, energy distribution, phase of the elastic wave-fields are spatially changed in 3-D dual-phase anisotrcpic media. |
| Key words: 3-D dual-phase anisotropic media elastic wave-fields staggered-grid high-order finite difference method |
