Development of an empirical model relating permeability and specific stiffness for rough fractures from numerical deformation experiments
Development of an empirical model relating permeability and specific stiffness for rough fractures from numerical deformation experiments
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DOI：
10.1002/2016jb013004
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发表时间：
2016-07
期刊：
影响因子：
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通讯作者：
Lichun Wang;M. Cardenas
中科院分区：
文献类型：
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作者：
Lichun Wang;M. Cardenas
多孔和裂缝地质介质的水力和机械特性之间的耦合对于许多地球物理过程和实际应用至关重要。因此，预测这些特性之间的联系非常重要。在这里，我们提出了一个潜在的预测模型，它将裂缝渗透率和比刚度与依赖于裂缝粗糙度、孔径场相关长度和岩石力学特性的经验系数联系起来。该方程是根据孔径场服从正态分布的合成裂缝的变形和流动建模结果凭经验得出的。骨折受到不断增加的法向应力并按照弹性模型变形。从这些数值变形实验中直接量化比刚度。通过计算局部流场估算渗透率，同时考虑局部裂缝粗糙度和弯曲度的影响。经验模型粗略地捕捉了随着比刚度的增加，从有效介质到渗流流态的转变。
The coupling between hydraulic and mechanical properties of porous and fractured geologic media are critical for many geophysical processes and practical applications. Thus, the prediction of this linkage between these properties is broadly important. Here we present a potentially predictive model that links fracture permeability and specific stiffness with empirical coefficients dependent on fracture roughness, correlation length of aperture field, and rock mechanical properties. The equation was developed empirically from results of modeling the deformation and flow through synthetic fractures with aperture fields that follow a normal distribution. The fractures were subjected to increasing normal stress and deformed following an elastic model. Specific stiffness was directly quantified from these numerical deformation experiments. Permeability was estimated through calculation of the local flow field while considering effects of local fracture roughness and tortuosity. The empirical model roughly captures the transition from effective medium to percolation flow regimes with increasing specific stiffness.