Experimental and modeling study of fluid pressure‐driven fractures in Darley Dale sandstone
Experimental and modeling study of fluid pressure‐driven fractures in Darley Dale sandstone
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Darley Dale 砂岩流体压力驱动裂缝的实验和模拟研究
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
J. Hazzard
中科院分区：
文献类型：
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作者：
S. Vinciguerra;P. Meredith;J. Hazzard
我们报告了 Darley Dale 砂岩圆柱形样品中压力驱动裂缝形成和生长过程中产生的声发射 (AE) 的测量结果，这些样品经过同轴预钻孔，以便施加内部压力。在流体压力约为围压的三倍时，一组 3 至 6 条裂缝在内孔壁处萌生，但只有 3 条裂缝扩展至样品的外壁。声发射的时间和空间分布显示出两种不同的活动爆发，分别与起始和传播相关。粒子流代码 (PFC) 模型已用于重现断裂萌生的力学以及 AE 的时间和空间分布。在实验和模型中，我们观察到了裂缝形成之前加速 AE 活动的独特阶段。
We report measurements of acoustic emissions (AE) generated during formation and growth of pressure driven fractures in cylindrical samples of Darley Dale sandstone that were co‐axially pre‐drilled in order to allow an internal pressure to be applied. A set of 3 to 6 fractures initiate at the wall of the internal bore at a fluid pressure around three times that of the confining pressure, but only 3 propagate to the outer wall of the sample. Time and spatial distributions of acoustic emissions show two distinct bursts of activity, associated with initiation and propagation, respectively. A Particle Flow Code (PFC) model has been used to reproduce the mechanics of fracture initiation and the time and spatial distributions of AE. In both the experiments and the model, we observe a distinct phase of accelerating AE activity preceding fracture formation.