Analytical seismic wave attenuation and velocity dispersion in layered double-porosity media
Analytical seismic wave attenuation and velocity dispersion in layered double-porosity media
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DOI：
10.4401/ag-7649
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发表时间：
2018-07
影响因子：
1
通讯作者：
Zhengyang Zhao;Xingyao Yin;Z. Zong
中科院分区：
文献类型：
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作者：
Zhengyang Zhao;Xingyao Yin;Z. Zong
由于多孔介质中不同区域的岩石性质如孔隙度、渗透率和可压缩性的差异，在这些不同区域之间诱导压力梯度并导致局部流体流动。地震波在多孔介质中传播时，局部流体流动过程是引起波衰减和速度频散的主要原因。许多作者在没有解析波动方程和求解这类岩石物理模型的数值方法中研究了层状孔隙模型的局部流体流动机理。在本研究中，我们首先建立一个单一流体饱和的层状双孔隙模型，并推导出波动方程。根据所导出的新波动方程，基于平面波分析方法计算了层状双重介质中的相速度和品质因子。结果表明，当纵波垂直于层状多孔介质传播时，在层状多孔介质中存在三种波型，即快纵波和两种慢纵波。最后，通过分析地震波在低频范围内的衰减和速度频散，研究了局部流体流动对介观损失机制的影响。
Due to differences of rock properties such as porosity, permeability and compressibility between different regions in the porous media, pressure gradients are induced between those different regions and lead to local fluid flow. When seismic wave propagates in the porous media, the local fluid flow process is a main cause of wave attenuation and velocity dispersion. The local fluid flow mechanism of the layered porous model has been studied by many authors in the numerical approaches without analytical wave equations and solution for this kind of rock physics models. In this study, we first establish a layered double-porosity model saturated with a single fluid and derive the wave equations. According to the derived novel wave equations, then we calculate the phase velocity and quality factor in the layered double-porosity media based on plane wave analysis. The results demonstrate that there are three kinds of wave modes named as the fast P-wave and two slow P-wave in layered porous media when P-wave propagates through the model perpendicularly. Finally, we study the effects of local fluid flow on the mesoscopic loss mechanism by analyzing the attenuation and the velocity dispersion of seismic waves in the low frequency range.