1887
Volume 27, Issue 4
  • ISSN: 0812-3985
  • E-ISSN: 1834-7533

Abstract

Both seismic and EM measurements are used to provide information about the geometry of coal seams in advance of longwall mining. However, each method has limitations and the results may be capable of several different interpretations. An approach which is now common in such cases is the joint application of two or more independent types of measurements to help resolve ambiguity. This paper describes the application of long-offset transient electromagnetic (LOTEM) sounding in Australian coal mining at the West Cliff Colliery, New South Wales. A feasibility study was carried out before the field survey in order to obtain the optimum measurement parameters. The interpretation of LOTEM data is based on both 1-D and 2.5-D automatic inversion techniques. Using prior information from seismic surveys and well logs, it was possible to map the electrical properties in coal seams. Since the electrical properties are closely related to stress as well as water saturation in coal seams within a sedimentary pile, quantitative relationships between the changes in stress or water saturation and electrical properties can therefore be established. The results indicated that the progress of drainage and of stress advance in association with mining can be monitored by measuring the changes of resistivity in coal seams from the surface using the LOTEM method.

© 1996 ASEG
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1996-09-01
2026-01-15

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References

  1. Archie, G.E., 1942, The electrical resistivity log as an aid in determining some reservoir characteristics: Transactions AIME 146, 54-62.
  2. Eadie, T, 1981, Detection of hydrocarbon accumulation by surface electrical methods: a feasibility study: Research in Applied Geophysics 15, University of Toronto.
  3. George, A., 1973, Nested dissection of a regular finite element mesh: SIAM Journal of Numerical Analysis, 10, 345-363.
  4. Hoerdt, A., Druskin, V.L., Knizhnerman, LA. and Strack, K.-M., 1992, Interpretation of 3-D effects in long-offset transient electromagnetic (LOTEM) soundings in the Munsterland area, Germany: Geophysics, 57, 1127-1137.
  5. Hoerdt, A., Strack, K.-M., Vozoff, K.and Wolfgram, P.A., 1990, Resolving resistive layers using joint inversion of LOTEM and MT data. In: A. Vogel (ed.), Inverse Modelling in Exploration Geophysics, Vieweg and Sohn, Braunschweig.
  6. Jupp, D.L.B. and Vozoff, K., 1975, Stable iterative methods for the inversion of geophysical data: Geophysical Journal of the Royal Astronomical Society, 42, 957-976.
  7. Jupp, D.L.B. and Vozoff, K., 1977, Two-dimensional magnetotelluric inversion: Geophysical Journal of the Royal Astronomical Society, 50, 333-352.
  8. Kaufman, A.A. and Keller, G.V., 1983, Frequency and transient sounding: Elsevier, Amsterdam.
  9. Lin, Z., 1996, 2.5D modelling and inversion of deep transient electromagnetic sounding with a grounded source: Ph.D thesis, Macquarie University (unpublished).
  10. Madden, T.R., 1973, Instruction manual for EMCDC and EMUVC (EMCAL), Exploration Aids Inc., Needham, Massachussetts.
  11. Passalacqua, H., 1983, Electromagnetic fields due to a thin resistive layer: Geophysical Prospecting, 31, 945-976.
  12. Petry, H., 1987, Transient elektromagnetische Tiefensondierung-odellrechnun-gen und Inversion: Diploma thesis, University of Cologne (unpublished).
  13. Raiche, A.P., Jupp, D.L.B., Rutter, H. and Vozoff, K., 1985, The joint use of coincident loop transient electromagnetic and Schlumberger sounding to resolve layered structures: Geophysics, 50, 1618-1627.
  14. Rodi.W.L., Swanger, H.J.and Minster, J.B., 1983, ESP/MT:an interactive system for two-dimensional magnetotelluric interpretation: SEG extended abstract, 151.
  15. Schlumberger, 1987, Log interpretation principles/applications: Schlumberger Educational Services.
  16. Smith, G.H., Williamson, PR. and Vozoff, K., 1990, The application of nested dissection to the solution of a 2.5D electromagnetic problem:The Applied Computational Electromagnetics Society Journal, 5, 87-106.
  17. Stephan, A., Schniggenfittig, H.and Strack, K.-M., 1991. Long-offset transient sounding, north of the Rhine-Ruhr coal district, Germany: Geophysical Prospecting, 39, 505-525.
  18. Stoyer, H.C. and Greenfield, R.J., 1976, Numerical solutions of the response of a two-dimensional earth to an oscillating magnetic dipole source: Geophysics, 41, 519-530.
  19. Strack, K.-M., 1992, Exploration with deep transient electromagnetics: Elsevier, Amsterdam.
  20. Strack, K.-M. and Engels, O.G., 1990, LOTEM processing system: user's reference guide, vol. 2.5, HarbourDom Consulting GmbH, Germany.
  21. Strack, K.-M., Hanstein, T, LeBrocq, K., Moss, D.C., Vozoff, K. and Wolfgram, P.A., 1989, Case histories of long-offset transient electromagnetic (LOTEM) in hydrocarbon prospective areas: First Break, 7, 467-477.
  22. Vozoff, K. and Jupp, D.L.B., 1975, Joint inversion of geophysical data, Geophysical Journal of the Royal Astronomical Society, 42, 977-991.
  23. Vozoff, K., LeBrocq, K., Moss, D., Zile, M.and Pridmore, D., 1985, Deep transient electromagnetic soundings for petroleum exploration, Final Report to NERDDC, CGER, Macquarie University (unpublished).
  24. Vozoff, K., Smith, G.H., Hatherly, P.J. and Thomson, S., 1993, An overview of the Radio Imaging Method in Australian coal mining: First Break, 10, 13-21.
  25. Williamson, PR., 1988, A study of diakoptics, graph theory and sparse matrix methods for geophysical field problems, Report to Centre for Geophysical Exploration Research, Macquarie University (unpublished).
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  • Article Type: Research Article
Keyword(s): 1-D inversion; 2.5-D inversion; coal characterisation; data processing; joint application; LOTEM; monitoring reservoir changes; West Cliff Colliery

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