Abstract
We addressed effects of in situ stress on the formation of flow pathways in fractured rocks in geothermal reservoirs, especially for HDR projects. Here we focused on fractures which are critically-stressed, causing shear slip in a current stress field. The sliding is likely to break sealing in the fractures and, as a result, to increase their permeability. Such a mechanism is possibly significant under high-temperature conditions at geothermal fields because of temperature enhancement on chemical reactions for the sealing. We present a procedure to estimate the orientation of the critically-stressed fractures relative to axes of in situ principal stress with the aid of the Mohr diagram. The procedure allows us to evaluate intuitively how the orientation changes with factors such as magnitude of in situ principal stresses and pore pressure. We applied the procedure to estimate possible orientations of the critically-stressed fractures in major HDR test sites. Results show that overall alignments of microseismicity during hydraulic stimulation are within predicted ranges for possible orientations of the critically-stressed fractures. Furthermore, it was found that if the state of in situ stress is not favorable to cause sliding of natural fractures, it tends to lead a high wellhead pressure at hydraulic stimulation and a high recovery rate at circulation. On the other hand, if the state of in situ stress is favorable for sliding, it tends vice versa to lead a low wellhead pressure at hydraulic stimulation and a low recovery rate at circulation
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Armstead, H. C. H. and Tester, J. W., Heat Mining: A New Source of Energy (E. &F. N. Spon, London 1987) Chap. 9, pp. 161–240
Atsumi, A., Introduction to Mechanics of Solids (in Japanese) (Corona Publ. Co., Tokyo 1978) Chap. 2.12, pp. 26–30.
Baria, R., Garnish, J., Baumgärtner, J., Gerald, A., and Reinhard,J.,Recent Development in the European HDR Research Programme at Soultz-Sous-Forets (France), Proc. World Geoth. Cong. (eds. E. Barbier, G. Frye, E. Iglesias and G. Pálmason)(Int. Geoth. Assoc., Inc., Auckland 1995) Vol. 4, pp. 2631–2635.
Barton, C. A., Zoback, M. D., and Moos, D. (1995), Fluid Flow along Potentially Active Faults in Crystalline Rock, Geology 23(8), 683–686.
Byerlee, J. (1978), Friction of Rocks, Pure and Appl. Geophys. 116, 615–626.
Fehler, M. C. (1989), Stress Control of Seismicity Patterns Observed during Hydraulic Fracturing Experiments at the Fenton Hill Hot Dry Rock Geothermal Energy Site, NewMexico, Int. J. Rock Mech. Min. Sci. and Geomech. Abstr. 26(3/4), 211–219.
Hickman, S., Barton, C. B., Zoback, M. D., Morin, R., Sass, J., and Benoit, R. (1997), In Situ Stress and Fracture Permeability in a Fault-Hosted Geothermal Reservoir at Dixie Valley, Nevada, Geoth. Res. Coun. Trans. 21, 181–189.
ITo, T. and Zoback, M. D. (2000), Fracture Permeability and In Situ Stress to 7 km Depth in the KTB Scientific Drillhole, Geophys. Res. Lett. 27(7), 1045–1048.
Mcgarr, A. (1999), On Relating Apparent Stress to the Stress Causing Earthquake Fault Slip, J. Geophys. Res. 104(B2), 3003–3011.
Olsen, M. P., Scholz, C. H., and Léger, A. (1998), Healing and Sealing of a Simulated Fault Gouge under Hydrothermal Conditions: Implications for Fault Healing, J. Geophys. Res. 103(B4), 7421–7430.
Parker, R. (1999), The Rosemanowes HDR Project 1983–1991, Geothermics 28(4/5), 603–615.
Phillips, W. S.,House, L. S.,and Fehler, M. C.(1997),Detailed Joint Structure in a Geothermal Reservoir from Studies of Induced Microearthquake Clusters, J.Geophys. Res. 102(B6), 11745–11763.
Pine, R. J. and Batchelor, A. S. (1984), Downward Migration of Shearing in Jointed Rock during Hydraulic Injections, Int. J. Rock Mech. Min. Sci. and Geomech. Abstr. 21(5), 249–263.
Pollard, D. D. and Segall, P., Theoretical displacements and stresses near fractures in rock: With applications to faults, joints, veins, dikes, and solution surfaces, In Fracture Mechanics of Rocks (ed. B. K.Atkinson ) (Academic Press Inc., London 1987), pp. 277–349.
Willis-Richards, J., Green, A. S. P., and Jupe, A., A Comparison of HDR Geothermal Sites, Proc. World Geoth. Cong. (eds. E. Barbier, G. Frye, E. Iglesias and G. Pálmason) (Int. Geoth. Assoc., Inc., Auckland 1995) Vol. 4, pp. 2601–2605.
Yeo, I. W., DE Freitas, M. H., and Zimmerman, R. W. (1998), Effect of Shear Displacement on the Aperture and Permebility of a Rock Fracture, Int. J. Rock. Mech. Min Sci. 35(8), 1051–1070.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2003 Springer Basel AG
About this chapter
Cite this chapter
Ito, T., Hayashi, K. (2003). Role of Stress-controlled Flow Pathways in HDR Geothermal Reservoirs. In: Kümpel, HJ. (eds) Thermo-Hydro-Mechanical Coupling in Fractured Rock. Pageoph Topical Volumes. Birkhäuser, Basel. https://doi.org/10.1007/978-3-0348-8083-1_19
Download citation
DOI: https://doi.org/10.1007/978-3-0348-8083-1_19
Publisher Name: Birkhäuser, Basel
Print ISBN: 978-3-7643-0253-5
Online ISBN: 978-3-0348-8083-1
eBook Packages: Springer Book Archive