Hostname: page-component-76fb5796d-vvkck Total loading time: 0 Render date: 2024-04-29T03:49:31.342Z Has data issue: false hasContentIssue false

The role of stress history on the flow of fluids through fractures

Published online by Cambridge University Press:  05 July 2018

S. Sathar
Affiliation:
British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG, UK
H. J. Reeves
Affiliation:
British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG, UK
R. J. Cuss*
Affiliation:
British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG, UK
J. F. Harrington
Affiliation:
British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG, UK
*
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Understanding flow along fractures and faults is of importance to the performance assessment (PA) of a geological disposal facility (GDF) for radioactive waste. Flow can occur along pre-existing fractures in the host-rock or along fractures created during the construction of the GDF within the excavation damage zone (EDZ). The complex fracture network will have a range of orientations and will exist within a complex stress regime. Critical stress theory suggests that fractures close to localized shear failure are critically stressed and therefore most conductive to fluid flow. Analysis of fault geometry and stress conditions at Sellafield has revealed that no features were found to be, or even close to being, classified as critically stressed, despite some being conductive. In order to understand the underlying reasons why non-critically stressed fractures were conductive a series of laboratory experiments were performed. A bespoke angled shear rig (ASR) was built in order to study the relationship between fluid flow (water and gas) through a fracture surface as a function of normal load. Fluid flow reduced with an increase in normal load, as expected. During unloading considerable hysteresis was seen in flow and shear stress. Fracture flow was only partially recovered for water injection, whereas gas flow increased remarkably during unloading. The ratio of shear stress to normal stress seems to control the fluid flow properties during the unloading stage of the experiment demonstrating its significance in fracture flow. The exhumation of the Sellafield area during the Palaeogene–Neogene resulted in considerable stress relaxation and in fractures becoming non-critically stressed. The hysteresis in shear stress during uplift has resulted in faults remaining, or becoming, conductive. The field and laboratory observations illustrate that understanding the stress-history of a fractured rock mass is essential, and a mere understanding of the current stress regime is insufficient to estimate the flow characteristics of present-day fractures.

Type
Research Article
Creative Commons
Creative Common License - CCCreative Common License - BY
© [2012] The Mineralogical Society of Great Britain and Ireland. This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY) licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2012

References

Armitage, P., Holton, D., Jefferies, N.L., Myatt, B.J. and Wilcock, P.M. (1996) Groundwater Flow Through Fractured Rock at Sellafield. Nuclear Science and Technology EUR 16870. European Comission, Brussels.Google Scholar
Barton, C.A., Zoback, M.D. and Moos, D. (1995) Fluid flow along potentially active faults in crystalline rock. Geology, 23, 683686.2.3.CO;2>CrossRefGoogle Scholar
Bossart, P., Meier, P.M., Moeri, A., Trick, T. and Mayor, J.-C. (2002) Geological and hydraulic characterisation of the excavation disturbed zone in the Opalinus Clay of the Mont Terri Rock Laboratory. Engineering Geology, 66, 1938.CrossRefGoogle Scholar
Bowden, R.A., Bumpus, C. and Littleboy, A.K. (1998) An overview and update of the site characterization studies at Sellafield. Proceedings of the Yorkshire Geological Society, 52, 125137.CrossRefGoogle Scholar
Brace, W., Walsh, J. and Frangos, W. (1968) Permeability of granite under high pressure. Journal of Geophysical Research, 73, 22252236.CrossRefGoogle Scholar
Brereton, N.R., Evans, C.J., Rogers, S.F., Kingdon, A. and Heaven, R.E. (1997) Geomechanical Modelling and Anisotropy at the Reservoir Scale. BGS Report No. WK/97/2C. British Geological Survey, Keyworth, Nottingham, UK.Google Scholar
Brudy, M., Zoback, M.D., Fuchs, K., Rummel, F. and Baumgärtner, J. (1997) Estimation of the complete stress tensor to 8 km depth in the KTB scientific drill holes: implications for crustal strength. Journal of Geophysical Research - Solid Earth, 102, 18,453-18475.CrossRefGoogle Scholar
Chadwick, R., Kirby, G. and Baily, H. (1994) The post- Triassic structural evolution of north-west England and adjacent parts of the East Irish Sea. Proceedings of the Yorkshire Geological Society, 50, 91102.CrossRefGoogle Scholar
Cuss, R.J., Milodowski, A.E. and Harrington, J.F. (2011) Fracture transmissivity as a function of normal and shear stress: first results in Opalinus Clay. Physics and Chemistry of the Earth, Parts A/B/C, 36, 19601971.CrossRefGoogle Scholar
Evans, C. and Brereton, N. (1990) In situ crustal stress in the United Kingdom from borehole breakouts. Geological Society, London, Special Publications, 48, 327338.Google Scholar
Finkbeiner, T., Barton, C.A. and Zoback, M.D. (1997) Relationships among in-situ stress, fractures and faults, and fluid flow, Monterey Formation, Santa Maria Basin, California. AAPG Bulletin, 81, 19751999.Google Scholar
Gutierrez, M., Øino, L.E., and Nygård, R. (2000) Stressdependent permeability of a de-mineralised fracture in shale. Marine and Petroleum Geology, 17, 895907.CrossRefGoogle Scholar
Heffer, K. and Lean, J. (1993) Earth stress orientation - a control on, and guide to, flooding directionality in a majority of reservoirs. Pp. 799822in: Reservoir Characterization III (W. Linville, editor). PennWell Books, Tulsa, Oklahoma, USA.Google Scholar
Huenges, E. and Will, G. (1989) Permeability, bulk modulus and complex resistivity in crystalline rocks. Pp. 361375.in: Fluids Movements - Element Transport and the Composition of the Deep Crust (D. Bridgwater, editor). Kluwer Academic Publishers, Dordrecht, The Netherlands.Google Scholar
Jaeger, J.C., Cook, N.G.W. and Zimmerman, R.W. (2007) Fundamentals of Rock Mechanics. Wiley- Blackwell, Chichester, UK.Google Scholar
Laubach, S.E., Olson, J.E. and Gale, J.F.W. (2004) Are open fractures necessarily aligned with maximum horizontal stress? Earth and Planetary Science Letters, 222, 191195.Google Scholar
Lewis, C.L.E., Green, P.F., Carter, A. and Hurford, A.J. (1992) Elevated K/T palaeotemperatures throughout Nortwest England: three kilometres of Tertiary erosion? Earth and Planetary Science Letters, 112, 131145.Google Scholar
Michie, U. (1996) The geological framework of the Sellafield area and its relationship to hydrogeology. Quarterly Journal of Engineering Geology and Hydrogeology, 29, S13S27.CrossRefGoogle Scholar
Millward, D., Beddoe-Stephens, B., Williamson, I., Young, S . and Petterson , M. (1994 ) Lithostratigraphy of a concealed caldera-related ignimbrite sequence within the Borrowdale Volcanic Group of west Cumbria. Proceedings of the Yorkshire Geological Society, 50, 2536.CrossRefGoogle Scholar
Nirex (1996) Assessment of the In-situ Stress Field at Sellafield - Main Report. UK Nirex Ltd. Report No. SA/96/004.Google Scholar
Nirex (1997) Locations of Flow Zones in Sellafield Deep Boreholes. UK Nirex Ltd. Report No. SA/97/073.Google Scholar
Paillet, F.L. and Kim, K. (1987) Character and distribution of borehole breakouts and their relationship to in situ stresses in deep Columbia River basalts. Journal of Geophysical Research, 92, 62236234.CrossRefGoogle Scholar
Pratt, H., Swolfs, H., Brace, W., Black, A. and Handin, J. (1977) Elastic and transport properties of an in situ jointed granite. International Journal of Rock Mechanics and Mining Science and Geomechanical Abstracts, 14, 3545.CrossRefGoogle Scholar
Reeves, H. (2002) The Effect of Stress and Fractures on Fluid Flow in Crystalline Rocks, Cumbria. Unpublished PhD thesis, University of Durham, Durham, UK, 239 pp.Google Scholar
Reeves, H., Cuss, R. and Evans, C. (2003) Critical stress analysis as a predictor of fluid flow; the answer or just another piece of the jigsaw? In: Proceedings Fault and Top Seals: What do we know and where do we go? EAGE Conference, Montpellier, France, 811.September 2003.Google Scholar
Rice, J.R. (1992) Fault stress states, pore pressure distributions, and the weakness of the San Andreas Fault. International Geophysics, 51, 475503.CrossRefGoogle Scholar
Rider, M.H. (1986) The Geological Interpretation of Well Logs. Whittles, Caithness, UK.Google Scholar
Rogers, S.F. (2003) Critical stress-related permeability in fractured rocks. Pp. 716.in: Fracture and In-situ Stress Characterization of Hydrocarbon Reservoirs (M. Ameen, editor) Geological Society, London.Google Scholar
Rogers, S.F. and Evans, C.J. (2002) Stress-dependent flow in fractured Rocks at Sellafield, United Kingdom. Pp. 241250.i n : Geological Applications of Well Logs (M. Lovell and N. Parkinson, editors). AAPG Methods in Exploration No. 13. The American Association of Petroleum Geologists, Tulsa, Oklahoma, USA.Google Scholar
Rutqvist, J., Börgesson, L., Chijimatsu, M., Hernelind, J., Jing, L., Kobayashi, A. and Nguyen, S. (2009) Modeling of damage, permeability changes and pressure responses during excavation of the TSX tunnel in granitic rock at URL, Canada. Environmental Geology, 57, 12631274.CrossRefGoogle Scholar
Standen, E. (1991) Tips for analyzing fractures on electrical wellbore images. World Oil, 212, 99118.Google Scholar
Tsang, C.F., Bernier, F. and Davies, C. (2005) Geohydromechanical processes in the Excavation Damaged Zone in crystalline rock, rock salt, and indurated and plastic clays - in the context of radioactive waste disposal. International Journal of Rock Mechanics and Mining Sciences, 42, 109125.CrossRefGoogle Scholar
Zoback, M.D., Moos, D., Mastin, L. and Anderson, R.N. (1985) Well bore breakouts and in situ stress. Journal of Geophysical Research - Solid Earth, 90, 55235530.CrossRefGoogle Scholar