The effect of crack orientation on the nonlinear interaction of a P wave with an S wave
The effect of crack orientation on the nonlinear interaction of a P wave with an S wave
复制标题
裂纹方向对 P 波与 S 波非线性相互作用的影响
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
M. Fehler
中科院分区：
文献类型：
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作者：
J. Tencate;A. Malcolm;X. Feng;M. Fehler
裂缝、节理、流体和其他孔隙尺度结构长期以来一直被假设是岩石中观察到的大弹性非线性的原因。然而，由于很难分离出非线性相互作用的来源，很难确定哪个孔隙尺度特征是最重要的。在这项工作中，我们关注裂纹对记录的非线性信号的影响，特别是微裂纹的方向如何改变非线性相互作用的强度。我们通过研究取向对测量结果的影响来做到这一点，岩石的各向异性与微裂缝的存在和排列有关。我们通过高振幅S波泵浦在低振幅P波探头中引起的行时延迟来测量非线性响应。结果表明，裂纹取向对非线性信号有显著影响。
Cracks, joints, fluids, and other pore‐scale structures have long been hypothesized to be the cause of the large elastic nonlinearity observed in rocks. It is difficult to definitively say which pore‐scale features are most important, however, because of the difficulty in isolating the source of the nonlinear interaction. In this work, we focus on the influence of cracks on the recorded nonlinear signal and in particular on how the orientation of microcracks changes the strength of the nonlinear interaction. We do this by studying the effect of orientation on the measurements in a rock with anisotropy correlated with the presence and alignment of microcracks. We measure the nonlinear response via the traveltime delay induced in a low‐amplitude P wave probe by a high‐amplitude S wave pump. We find evidence that crack orientation has a significant effect on the nonlinear signal.