Slow waves in fractures filled with viscous fluid
Slow waves in fractures filled with viscous fluid
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DOI：
10.1190/1.2802174
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发表时间：
2008
期刊：
影响因子：
3.3
通讯作者：
V. Korneev
中科院分区：
文献类型：
--
作者：
V. Korneev
在流体填充的裂缝中的斯通利导波通常具有比其他波更大的振幅，因此，需要将它们的特性纳入更现实的模型中。在这项研究中，一个裂缝被建模为一个无限层的粘性流体边界的两个弹性半空间具有相同的参数。对于小裂缝厚度，得到了一个简单的波传播速度频散方程。该速度远小于毕奥型解中的流体波的速度，在毕奥型解中，裂缝壁被假定为刚性的。在地震勘探频率和实际裂缝厚度下，Stoneley导波具有几米量级的波长和超过10的衰减Q因子，这表明含流体岩石中共振激发的可能性。水和油的斯通利波的速度和衰减在低频处有明显的不同。在现场规模的流体流动中的裂缝的主导作用是支持的渗透率数据显示增加了几个数量级相比，在实验室规模获得的值。这些数据表明，斯通利波导波应考虑在理论描述地震波在流体饱和岩石中的传播。
Stoneley guided waves in a fluid-filled fracture generally have larger amplitudes than other waves, and therefore, their properties need to be incorporated in more realistic models. In this study, a fracture is modeled as an infinite layer of viscous fluid bounded by two elastic half-spaces with identical parameters. For small fracture thickness, I obtain a simple dispersion equation for wave-propagation velocity. This velocity is much smaller than the velocity of a fluid wave in a Biot-type solution, in which fracture walls are assumed to be rigid. At seismic prospecting frequencies and realistic fracture thicknesses, the Stoneley guided wave has wavelengths on the order of several meters and an attenuation Q factor exceeding 10, which indicates the possibility of resonance excitation in fluid-bearing rocks. The velocity and attenuation of Stoneley guided waves are distinctly different at low frequencies for water and oil. The predominant role of fractures in fluid flow at field scales is supported by permeability data showing an increase of several orders of magnitude when compared to values obtained at laboratory scales. These data suggest that Stoneley guided waves should be taken into account in theories describing seismic wave propagation in fluid-saturated rocks.