摘要
黏弹性和各向异性广泛地存在于地球介质中。因此,将黏声拟微分方程的衰减项扩展到VTI拟微分方程中,提出一种黏声VTI拟微分方程,该方程可以同时考虑黏弹性和VTI性质。使用有限差分法求解该方程,其中衰减项在波数域求解,而其他项是在时—空域求解。在此基础上,发展了黏声VTI介质双程波照明分析方法。均匀模型的正演数值试验证明,本文提出的黏声VTI拟微分方程可以准确地描述地震波在黏声VTI介质中传播的运动学和动力学特征;凹陷模型的正演模拟说明介质的VTI性质引起了走时和波形的差异,而黏弹性导致了振幅的衰减;从最终的照明分析结果可以看出黏弹性和VTI性质影响波场能量的分布。
The visco-elasticity and anisotropy widely exist in the earth.Therefore,the attenuation term of visco-acoustic quasi-differential equation is extended to VTI quasi-differential equations to propose visco-acoustic VTI quasi-differential equations,which care for both visco-elastic and VTI properties of media.The finite difference method is used to solve the equations,in which attenuation terms are solved in the wave-number domain,while other terms are solved in the time-space domain.On this basis,we develop a two-way wave illumination analysis method in visco-acoustic VTI media.A homogeneous model forward modeling proves that the proposed visco-acoustic VTI quasi-differential equations can describe dynamics and kinematics characteristics of seismic wave propagating in the visco-acoustic VTI media.The forward modeling for a sag model shows that the VTI property causes traveltime and waveform difference,and the visco-elasticity leads to amplitude attenuation.Finally,the illumination analysis illustrates that the visco-elastic and VTI properties affect the energy distribution of the wave field.
出处
《石油地球物理勘探》
EI
CSCD
北大核心
2017年第5期906-914,共9页
Oil Geophysical Prospecting
基金
松辽外围西部盆地油气基础地质调查项目(DD20160164)
物化探所中央级公益性科研院所基本科研业务费专项资金(AS2017J11)联合资助
关键词
黏声介质
VTI介质
双程波波动方程
正演模拟
照明分析
visco-acoustic media
VTI media
two-way wave equation
forward modeling
illumination analysis
