Abstract
IN many geothermal systems, water migrates into vapour-dominated porous rock either through natural recharge or through forced injection of water from a well1–5. If the host rock is initially very hot, then a fraction of this injected water vaporizes6,7; as the water injection rate increases, the fraction which vaporizes decreases7. For modelling purposes, it is generally assumed that liquid–vapour interfaces in hot porous rocks are planar and stable6,7. But we show here, both theoretically and experimentally, that if a sufficient fraction of the liquid vaporizes, the interface can become unstable. The resulting 'fingering' instability can itself be stabilized: at short wavelengths by thermal diffusion, and at long wavelengths by the pressure increase caused by the excess vaporization at the tips of the fingers. These liquid fingers migrate through the porous rock much more rapidly than does a planar liquid front, and could therefore limit the time during which vapour may be extracted for geothermal power applications. We suggest that an optimal water injection rate for geothermal energy production may be that for which the interface is just stable, thereby maximizing the fraction of liquid which vaporizes, while suppressing the fingering instability.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
White, D. E., Muffler, L. J. P. & Truesdell, A. H. Econ. Geol. 66, 75–97 (1971).
Martini, M., Piccardi, G. & Cellini-Legittimo, P. Bull. volcan. 44, 109–113 (1981).
Bodvarrson, G. Geothermics 1, 63–66 (1972).
Schroeder, R. C., O'Sullivan, M. J., Pruess, K., Celati, R. & Ruffilli, C. Geothermics 11, 93–120 (1982).
Enedy, S., Enedy, K. & Manney, J. Proc. Stanford Workshop Geotherm. Reservoir Engng Vol. 16 (Stanford Geothermal Program, Stanford, California, 1991).
Pruess, K., Calore, C., Celati, R. & Wu, Y. S. Int. J. Heat Mass Transfer 30, 2595–2602 (1987).
Woods, A. W. & Fitzgerald, S. D. J. Fluid Mech. 251, 563–579 (1993).
Elder, J. Geothermal Systems (Academic, London, 1981).
Grant, M. A., Donaldson, I. G. & Bixley, P. F. Geothermal Reservoir Engineering (Academic, New York, 1982).
Kestin, J. Sourcebook on the Production of Electricity from Geothermal Energy (US Dept. of Energy, Washington DC, 1980).
Truesdell, A. H. & White, D. E. Geothermics 2, 154–173 (1973).
Brown, G. & Rymer, H. Nature 339, 370–373 (1989).
Cline, J. S., Bodnar, R. J. & Rimstidt, J. D. J. geophys. Res. 97, 9085–9103 (1992).
Hemley, J. J. & Hunt, J. P. Econ. Geol. 87, 23–43 (1992).
Kerr, R. A. Science 253, 134–135 (1991).
Enedy, K. Geotherm. Resour. Trans. 13, 383–391 (1989).
Schubert, G., Strauss, J. M. & Grant, M. A. Nature 287, 423–425 (1980).
Saffman, P. G. & Taylor, G. I. Proc. R Soc. A245, 312–329 (1958).
Hickernell, F. J. & Yortsos, Y. C. Stud. appl. Math. 74, 93–115 (1986).
Haywood, R. W. Thermodynamic Tables in SI (metric) Units (Cambridge Univ. Press, 1972).
Weast, R. C. Handbook of Chemistry and Physics (Chemical Rubber Co., 1972).
The Petroleum Handbook (Royal Dutch Shell Group, Balding & Mansell, Wisbech, UK, 1959).
Young, J. B. J. Engng Gas Turbines Power 110, 1–7 (1988).
Hinch, J. Perturbation Methods (Cambridge Univ. Press 1991).
Mullins, W. W. & Sekerka, R. F. J. appl. Phys. 35, 444–451 (1964).
Tan, C. T. & Homsy, G. M. Phys. Fluids 29, 3549–3556 (1986).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Fitzgerald, S., Woods, A. The instability of a vaporization front in hot porous rock. Nature 367, 450–453 (1994). https://doi.org/10.1038/367450a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/367450a0
This article is cited by
-
Spontaneous formation of nanoparticle stripe patterns through dewetting
Nature Materials (2005)
-
Criteria of hydrodynamic instability of a phase interface in hydrothermal systems
Fluid Dynamics (2004)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.