Modeling of fault slip during hydraulic stimulation in a naturally fractured medium
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Assessing the intensity of potential seismicity induced by fault slip is a mandatory task in the development of enhanced geothermal systems. In this paper numerical simulations are performed to investigate the propagation of hydraulic fractures and the slip behavior of existing faults due to fluid injection. The cohesive zone model is used in combination with finite cohesive elements to model the hydraulic fractures and the existing faults while the fault shear strength is assumed to follow the Coulomb friction law. Our focus is on the role of the friction conditions on the fault slip behavior. The simulation results show that faults with small friction coefficients tend to slip at low slip rates while faults with a higher friction coefficient tend to slip at rates that are higher than the unstable slip rate threshold. It is also demonstrated that under specific frictional conditions, the sequential stimulation mechanism of permeability enhancement is possible. The results suggest that a good characterization of the fault frictional conditions is required to successfully predict the fault slip pattern and that lowering the fault friction coefficient could potentially reduce the fault slip rate.
KeywordsGeoenergy Fault reactivation Induced seismicity Cohesive element Coulomb friction Hydro mechanical coupling
The authors would like to thank the GEOTREF project for financial support (www.geotref.com). This project is funded by ADEME within the “Les Investissements d’Avenir” Program. Partners of the GEOTREF project include Teranov, Kidova, MINES ParisTech, ENS Paris, GeoAzur, Georessources, IMFT, IPGS, LHyGes, UAG, and UCP-GEC. The authors also express their gratitude to the Dassault Système Foundation, which also supported this study.
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Conflict of interest
The authors wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome.
- ABAQUS (2016) Analysis user’s manual version R2016. Dassault Système, Vélizy-VillacoublayGoogle Scholar
- Carter E (1957) Optimum fluid characteristics for fracture extension. In: Howard GC, Fast C (eds) Drilling and production practice. American Petroleum Institute, WashingtonGoogle Scholar
- Ghassemi A, Tarasovs S (2015) Analysis of fracture propagation under thermal stress in geothermal reservoirs. In: Proceedings world geothermal congress 2015, Melbourne, AustraliaGoogle Scholar
- Jaeger JC, Cook NG, Zimmerman R (2009) Fundamentals of rock mechanics. Wiley, New YorkGoogle Scholar
- Keshavarz M (2009) Contribution to experimental study of mechanical and thermal damage in crystalline hard rocks. PhD dissertation, Université Joseph Fourier-Grenoble IGoogle Scholar
- Meyer G, Baujard C, Hehn R, Genter A, McClure M (2017) Analysis and numerical modelling of pressure drops observed during hydraulic stimulation of GRT-1 geothermal well (Rittershoffen, France). In: Proceedings 42nd workshop on geothermal reservoir engineering. Stanford University, Stanford, CAGoogle Scholar
- Niitsuma H, Fehler M, Jones R, Wilson S, Albright J, Green A, Baria R, Hayashi K, Kaieda H, Tezuka K, Jupe A, Wallroth T, Cornet F, Asanuma H, Moriya H, Nagano K, Phillips WS, Rutledge J, House L, Beauce A, Alde D, Aster R (1999) Current status of seismic and borehole measurements for HDR/HWR development. Geothermics 28:475–490CrossRefGoogle Scholar
- Selvadurai APS, Suvorov AP (2016) Thermo-poroelasticity and geomechanics. Cambridge University Press, CambridgeGoogle Scholar