期刊
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
卷 116, 期 -, 页码 -出版社
AMER GEOPHYSICAL UNION
DOI: 10.1029/2010JB007759
关键词
-
资金
- NSF [OCE-0648331, EAR-0545702]
- NWO (Dutch Science Foundation) [825.06.003]
- Directorate For Geosciences
- Division Of Earth Sciences [1045825] Funding Source: National Science Foundation
- Directorate For Geosciences
- Division Of Earth Sciences [0950517] Funding Source: National Science Foundation
We report on laboratory experiments designed to investigate the influence of pore pressure oscillations on the effective permeability of fractured rock. Berea sandstone samples were fractured in situ under triaxial stresses of tens of megapascals, and deionized water was forced through the incipient fracture under conditions of steady and oscillating pore pressure. We find that short-term pore pressure oscillations induce long-term transient increases in effective permeability of the fractured samples. The magnitude of the effective permeability enhancements scales with the amplitude of pore pressure oscillations, and changes persist well after the stress perturbation. The maximum value of effective permeability enhancement is 5 x 10 (16) m(2) with a background permeability of 1 x 10 (15) m(2); that is, the maximum enhanced permeability is 1.5 x 10(-15) m(2). We evaluate poroelastic effects and show that hydraulic storage release does not explain our observations. Effective permeability recovery following dynamic oscillations occurs as the inverse square root of time. The recovery indicates that a reversible mechanism, such as clogging/unclogging of fractures, as opposed to an irreversible one, like microfracturing, is responsible for the transient effective permeability increase. Our work suggests the feasibility of dynamically controlling the effective permeability of fractured systems. The result has consequences for models of earthquake triggering and permeability enhancement in fault zones due to dynamic shaking from near and distant earthquakes.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据