Elastic wave velocities and permeability of cracked rocks
Elastic wave velocities and permeability of cracked rocks
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DOI：
10.1016/s0040-1951(03)00184-7
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发表时间：
2003-07
期刊：
影响因子：
2.9
通讯作者：
Y. Guéguen;A. Schubnel
中科院分区：
文献类型：
--
作者：
Y. Guéguen;A. Schubnel
裂缝在大多数受地壳条件影响的岩石中起主要作用。从机械上讲，裂缝使岩石更加顺从。它们也使流体更容易流过任何岩石体。依靠断裂力学和统计物理学，我们引入了一些关键概念，这些概念允许理解和量化裂缝如何改变岩石的弹性和运输性质。介绍了推导岩石有效弹性模量的几种主要格式。实验结果表明，一个很好的近似是所谓的非相互作用的计划。裂纹对弹性波的存在的主要后果是弹性各向异性的发展（由于裂纹方向的各向异性分布）和色散效应（由于微观局部流体流动）。在更大的尺度上，宏观流体流动发生通过裂缝网络超过逾渗阈值。两种宏观流体流动状态可以区分：接近渗流阈值的稀释状态和远高于渗流阈值的连通状态。在非常不同的岩石类型上的实验数据显示了这两种行为。
Cracks play a major role in most rocks submitted to crustal conditions. Mechanically, cracks make the rock much more compliant. They also make it much easier for fluid to flow through any rock body. Relying on Fracture Mechanics and Statistical Physics, we introduce a few key concepts, which allow to understand and quantify how cracks do modify both the elastic and transport properties of rocks. The main different schemes, which can be used to derive the elastic effective moduli of a rock, are presented. It is shown from experimental results that an excellent approximation is the so-called non-interactive scheme. The main consequences of the existence of cracks on the elastic waves is the development of elastic anisotropy (due to the anisotropic distribution of crack orientations) and the dispersion effect (due to microscopic local fluid flow). At a larger scale, macroscopic fluid flow takes place through the crack network above the percolation threshold. Two macroscopic fluid flow regimes can be distinguished: the percolative regime close to the percolation threshold and the connected regime well above it. Experimental data on very different rock types show both of these behaviors.