TY - JOUR
T1 - Friction-Stability-Permeability Evolution of a Fracture in Granite
AU - Ishibashi, Takuya
AU - Elsworth, Derek
AU - Fang, Yi
AU - Riviere, Jacques
AU - Madara, Benjamin
AU - Asanuma, Hiroshi
AU - Watanabe, Noriaki
AU - Marone, Chris
N1 - Funding Information:
The authors thank the Editor Harihar Rajaram and the Associate Editor Larry Murdoch for handling the manuscript and the anonymous reviewers for their constructive suggestions. The authors thank Steve Swavely for assistance in the lab. The authors also thank Chaoyi Wang for his valuable suggestions. The present study was supported in part by JSPS, through Postdoctoral Fellowships for Research Abroad 26-709 (to T. I.) and as a partial result from DOE under grants DE-FE0023354 and DE-EE0006762 (to D. E. and C. M.). This support is gratefully acknowledged. The data supporting this paper are available from https://figshare.com/s/ 4e5942d9689e85a206d9.
Publisher Copyright:
©2018. American Geophysical Union. All Rights Reserved.
PY - 2018/12
Y1 - 2018/12
N2 - The evolution of frictional strength, stability, and fracture permeability is intimately linked both to the seismic cycle and to the impact of hydraulic stimulation for fractured reservoirs. However, despite this importance, the poromechanical relationships between fault permeability and strength remain unclear. The present study explores this relationship via laboratory experiments for concurrent shear-flow on smooth fractures of Westerly granite. The novelty of these experiments is that the shear velocity is precisely controlled during the measurement of fracture permeability. Results indicate permeability enhancement during velocity-weakening (potentially unstable) frictional slip. To decipher key processes contributing to this response, we evaluate the state of contacting asperities and of fracture surface asperities via digital rock fracture modeling of statistically equivalent surfaces. We propose two plausible mechanisms constraining the relationship between friction and permeability evolution—one based on changes in asperity contact distribution and one on shear-induced dilation triggered by changes in fault slip velocity. These mechanisms should be taken into account in interpreting field observation such as the abrupt permeability increase of natural faults at the onset of seismic slip.
AB - The evolution of frictional strength, stability, and fracture permeability is intimately linked both to the seismic cycle and to the impact of hydraulic stimulation for fractured reservoirs. However, despite this importance, the poromechanical relationships between fault permeability and strength remain unclear. The present study explores this relationship via laboratory experiments for concurrent shear-flow on smooth fractures of Westerly granite. The novelty of these experiments is that the shear velocity is precisely controlled during the measurement of fracture permeability. Results indicate permeability enhancement during velocity-weakening (potentially unstable) frictional slip. To decipher key processes contributing to this response, we evaluate the state of contacting asperities and of fracture surface asperities via digital rock fracture modeling of statistically equivalent surfaces. We propose two plausible mechanisms constraining the relationship between friction and permeability evolution—one based on changes in asperity contact distribution and one on shear-induced dilation triggered by changes in fault slip velocity. These mechanisms should be taken into account in interpreting field observation such as the abrupt permeability increase of natural faults at the onset of seismic slip.
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U2 - 10.1029/2018WR022598
DO - 10.1029/2018WR022598
M3 - Article
AN - SCOPUS:85057981255
VL - 54
SP - 9901
EP - 9918
JO - Water Resources Research
JF - Water Resources Research
SN - 0043-1397
IS - 12
ER -