杨富森, 李振春, 王小丹, 张凯, 刘成斋. 2015: 等价各向异性介质一阶拟声波 方程正演模拟及其效率分析. 地震学报, 37(4): 648-660. DOI: 10.11939/jass.2015.04.011
引用本文: 杨富森, 李振春, 王小丹, 张凯, 刘成斋. 2015: 等价各向异性介质一阶拟声波 方程正演模拟及其效率分析. 地震学报, 37(4): 648-660. DOI: 10.11939/jass.2015.04.011
Yang Fusen, Li Zhenchun, Wang Xiaodan, Zhang Kai, Liu Chengzhai. 2015: Equivalent anisotropic first-order pseudo-acoustic wave equations modeling and its efficiency analysis. Acta Seismologica Sinica, 37(4): 648-660. DOI: 10.11939/jass.2015.04.011
Citation: Yang Fusen, Li Zhenchun, Wang Xiaodan, Zhang Kai, Liu Chengzhai. 2015: Equivalent anisotropic first-order pseudo-acoustic wave equations modeling and its efficiency analysis. Acta Seismologica Sinica, 37(4): 648-660. DOI: 10.11939/jass.2015.04.011

等价各向异性介质一阶拟声波 方程正演模拟及其效率分析

Equivalent anisotropic first-order pseudo-acoustic wave equations modeling and its efficiency analysis

  • 摘要: 为克服各向异性弹性波动方程正演模拟的局限,本文研究了各向异性介质拟声波方程的交错网格有限差分数值解法.首先,从VTI介质胡克定律和qP-qSV波频散关系两种思路出发,通过声假设近似,给出了两种不同形式的VTI介质一阶拟声波方程,并通过引入波场的伪速度分量,推导了一种新的VTI介质一阶应力-速度方程,并通过旋转坐标系将其推广到TTI介质中;其次,构造了一阶拟声波方程的交错网格高阶有限差分格式,并推导了相应的PML边界条件;最后,对本文方法中固有的qSV人为干扰波的产生机制和压制方法进行了简单讨论.数值结果表明:3种一阶拟声波方程在运动学和动力学上是等价的,相对于各向异性弹性波正演模拟,其节省了内存,提高了计算效率;各向异性因素会影响反射波旅行时和振幅等波场特征,在后续的处理、反演和解释中不可忽略;VTI介质HESS模型的逆时偏移结果也验证了本文方法的合理性.

     

    Abstract: In order to overcome the limitations of anisotropic elastic wave equations modeling, this paper studied anisotropic pseudo-acoustic wave modeling by using staggered-grid finite-difference method. Starting from two different ideas, i.e., Hooke’s law and qP-qSV dispersion relation for VTI media, two first-order pseudo-acoustic wave equations in two forms for VTI media are given. Meanwhile, a new VTI first-order stress-velocity equations is derived through introducing the pseudo-velocity components of the wavefields, and then they are generalized to TTI media through the rotated coordinate system. Then the staggered-gird high-order finite-difference forms of the first-order pseudo-acoustic wave equations and the corresponding PML boundary condition are deduced. Finally, the inherent qSV-wave artifact generating mechanism and suppression method are discussed briefly. Numerical results show that the three first-order pseudo-acoustic wave equations are equivalent in kinematics and dynamics. Compared with anisotropic elastic wave modeling, they can save computational memory and enhance the efficiency. Anisotropic factor can affect the travel-time and amplitude of the reflection wave so we cannot ignore them in subsequent processing,inversion and interpretation. The reverse-time migration results of VTI-HESS model also validate the method proposed in this paper.

     

/

返回文章
返回