The Use of Borehole Breakout for Geotechnical Investigation of an Open Pit Mine

Authors: Fowler, MJ; Weir, FM

DOI https://doi.org/10.36487/ACG_repo/808_61

Cite As:
Fowler, MJ & Weir, FM 2008, 'The Use of Borehole Breakout for Geotechnical Investigation of an Open Pit Mine', in Y Potvin, J Carter, A Dyskin & R Jeffrey (eds), SHIRMS 2008: Proceedings of the First Southern Hemisphere International Rock Mechanics Symposium, Australian Centre for Geomechanics, Perth, pp. 541-550, https://doi.org/10.36487/ACG_repo/808_61

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Abstract:
This paper presents the methodology and results of a borehole breakout study using acoustic televiewer borehole images (ATV) as part of the geotechnical investigations at Olympic Dam mine in South Australia. ATV logging of boreholes is rapidly becoming a standard investigation tool for geological and geotechnical investigations. It is primarily being used to provide high quality structural orientation data. However, the ability to observe and measure borehole breakout provides information on in situ stress and is another benefit of this technique. This study located 154 cases of breakout in 38 of the 96 holes reviewed. The measurements are presented and compared with conventional stress testing from the existing underground operation comprising CSIRO HI-Cell and Acoustic Emission. This study presents a summary of the stress condition at Olympic Dam. Clear stress domains are apparent with perturbation adjacent to a known major structure that transects the deposit. The study demonstrates the reliability of borehole breakout as a means of estimating the stress field orientation and its usefulness in augmenting smaller data sets of conventional methods.

References:
AMC Consultants Pty Ltd (2007) Re-interpretation of the in situ stress field and its relationship with geologic structures at the Olymic Dam Mine. AMC Project 106113, 302 p.
Ask, M.V.S., Ask, D. and Christiansson, R. (2006) Detection of borehole breakouts at Forsmark site, Sweden. In-situ Rock Stress - Measurement, Interpretation and Application, Lu, Li, Kjøholt and Dhale (editors), Taylor & Francis, London, pp. 79–86.
Babcock, E.A. (1978) Measurement of subsurface fractures from dipmeter logs: AAPG Bulletin, 62(7), pp. 111–1126. Reprinted 1990 in Foster, N.H. and Beaumont, E.A. (editors) Formation evaluation II – log interpretation: AAPG Treatise of Petroleum Geology Reprint Series 17, pp. 457–472.
Bell, J.S. and Gough, D.I. (1979) Northeast-southwest compressive stress in Alberta: Evidence from oil wells. Earth and Planetary Science Letters 45(2), pp. 475–482.
Brudy, M. and Zoback, M.D. (1993) Compressive and tensile failure of boreholes arbitrarily-inclined to principal stress axes: application to the KTB boreholes, Germany. International Journal OF Rock Mechanics and Mining Sciences Geomechanics Abstracts 30, pp. 1035–1038.
Brudy, M. and Zoback, M.D. (1999) Drilling-induced tensile wall-fractures: implications for determination of in-situ stress orientation and magnitude. International Journal of Rock Mechanics and Mining Sciences 36, pp. 191–215.
Hillis, R.R. and Reynolds, S.D. (2003) In situ stress field of Australia. Evolution and Dynamics of the Australian Plate, R.R. Hillis and R.D. Műller (editors), Geological Society of Australia Special Publication 22, pp. 43–52.
Lund, B. and Zoback, M.D. (1999) Orientation and magnitude of in situ stress to 6.5 km depth in the Baltic Shield. International Journal of Rock Mechanics and Mining Sciences 36, pp. 169–190.
Martin, C.D. (1997) Seventeenth Canadian Geotechnical Colloqium: The effect of cohesion loss and stress path on brittle rock strength, Canadian Geotechnical Journal 34(5), pp. 698–725.
Moos, D. and Zoback, M.D. (1990) Utilization of observations of well bore failure to constrain the orientation and magnitude of crustal stresses: Application to continental, Deep Sea Drilling Project and Ocean Drilling Project boreholes. Journal of Geophysical Research 95(B6), pp. 9305–9325.
Plumb, R.A. (1989) Fracture patterns associated with incipient borehole breakouts. Rock at Great Depth, V. Maury and D. Fourmaintaux (editors), 2, Balkema, Rotterdam, pp. 761–768.
Plumb, R.A. and Hickman, S.H. (1985) Stress-induced borehole elongation: A comparison between the four-arm dipmeter and the borehole televiewer in the Auburn Geothermal well. Journal of Geophysical Research 90(B7), pp. 5513–5522.
Reynolds L.J. (2001) Geology of eth Olympic Dam Cu-U-Au-Ag-REE Deposit. Mesa Journal 23, October 2001, pp. 37–44.
Reynolds, S. (2008) Stress Maps, Australian School of Petroleum, Adelaide University. Available from: <> [accessed 5th April 2008]
Vernick, L. and Zoback, M.D. (1992) Estimation of maximum horizontal principal stress magnitude from stress-induced well bore breakouts in the Cajon Pass Scientific Research Borehole. Journal of Geophysical Research 97(B4), pp. 5109–5119.
Villaescusa, E., Li, J. and Windsor, C. (2005) Stress measurements from oriented core using the Acoustic Emission Method. Western Australian School of Mines, Curtin University of Technology Report for WMC Resources Limited, Olympic Dam Operations Southern Resource, unpublished.
Zajac, B.J. and Stock, J.M. (1997) Using borehole breakouts to constrain the complete stress tensor: Results from the Sijan Deep Drilling Project and offshore Santa Maria Basin, California. Journal of Geophysical Research 102(B5), pp. 10083–10100.
Zoback, M.L. and Zoback, M.D. (1980) State of stress in the conterminous United States. Journal of Geophysical Research 85(B11), pp. 6113–6156.
Zoback, M.D., Moos, D., Mastin, L. and Anderson, R.N. (1985) Well bore breakouts and in situ stress. Journal of Geophysical Research 90, pp. 5523–5530.




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