1887
1st Australasian Exploration Geoscience Conference – Exploration Innovation Integration
  • ISSN: 2202-0586
  • E-ISSN:

Abstract

The presence of chargeable materials can significantly impact the data in electromagnetic (EM) surveys. This affected data has traditionally been treated as noise that must be removed prior to interpretation or inversion. The ability to extract induced polarization (IP) information from an airborne platform would be a valuable tool in the mineral exploration industry, and thus the pursuit of this ability has recently led to significant interest in the interpretation of IP effects in airborne data. A variety of interpretation methodologies have been proposed to aid in the identification and extraction of information from time domain EM data containing IP effects. Any interpretation scheme needs to be thoroughly tested on realistic synthetic examples so that the strengths and weaknesses of the method are well understood.

In this work, we present a methodology for accurately and efficiently simulating the response of a time domain EM experiment by modelling the convolution that occurs in Ohm’s Law in the presence of a frequency dependent conductivity. This method is free of any assumptions about the dimensionality or frequency dependence of the chargeable material and can be used to simulate the response of any time domain system.

Loading

Article metrics loading...

/content/journals/10.1071/ASEG2018abM1_1E
2018-12-01
2026-01-13
Loading full text...

Full text loading...

References

  1. Bhattacharyya, B. (1964). Electromagnetic fields of a small loop antenna on the surface of a polarizable medium. Geophysics, 29(5):814-831.
  2. Commer, M., Petrov, P. V., and Newman, G. A., (2017). FDTD modelling of induced polarization phenomena in transient electromagnetics. Geophysical Journal International, 209(1):387-405
  3. da Silva, N. V., Morgan, J. V., MacGregor, L., and Warner, M. (2012). A finite element multi-frontal method for 3D CSEM modelling in the frequency domain. Geophysics, 77(2):E101 -E115.
  4. Flis, M., Newman, G. A., and Hohmann, G. W. (1989). Induced- polarization effects in time-domain electromagnetic measurements. Geo- physics, 54(4):514-523.
  5. Hohmann, G. W. and Newman, G. A. (1990). Transient electromagnetic responses of surficial, polarizable patches. Geophysics, 55(8):1098-1100.
  6. Lee, T. J. (1975). Sign Reversals in the Transient Method of Electrical Prospecting (OneLoop Version). Geophysical Prospecting, 23(4):653-662.
  7. Lee, T. J. (1981). Transient electromagnetic response of a polarizable ground. Geophysics, 46(7):1037-1041.
  8. Lee, T. J. and Thomas, L. (1992). The Transient Electromagnetic Response of a Polarizable Sphere in a Conducting Half Space. Geophysical prospecting, 40:541 -563.
  9. Lewis, R. J. G. and Lee, T. J. (1984). The Detection of Induced Polarization with a Transient Electromagnetic System. IEEE Transactions on Geoscience and Remote Sensing, GE-22(1):69-80.
  10. Marchant, D., Haber, E., and Oldenburg, D. W. (2014). Three-dimensional modelling of IP effects in time-domain electromagnetic data. Geophysics, 79(6):E303-E314.
  11. Marchant, D., 2015, Induced Polarization Effects in Inductive Source Electromagnetic Data: Ph.D. Thesis, University of British Columbia
  12. Morrison, H. F., Phillips, R., and O’Brien, D. (1969). Quantitative interpretation of transient electromagnetic fields over a layered half space. Geophysical prospecting, 14:82-101.
  13. Newman, G. A., Hohmann, G. W., and Anderson, W. L. (1986). Transient electromagnetic response of a three-dimensional body in a layered earth. Geophysics, 51(8):1608-1627.
  14. Rathor, B. (1978). Transient electromagnetic field of a polarizable half-space due to various current pulses. Geophysical Prospecting, 26:337-351.
  15. Smith, R. S., Walker, P., Polzer, B., and West, G. F. (1988). The time-domain electromagnetic response of polarizable bodies: an approximate convolution algorithm. Geophysical Prospecting, 36(April):772-785.
  16. Streich, R. (2009). 3D finite-difference frequency-domain modelling of controlled-source electromagnetic data: Direct solution and optimization for high accuracy. Geophysics, 74(5):F95-F105.
  17. Wait, J. and Debroux, P. (1984). Induced Polarization in Electromagnetic Inductive Schemes. Geophysical prospecting, 32:1147-1154.
  18. Zaslavsky, M. and Druskin, V. (2010). Solution of time-convolutionary Maxwells equations using parameter-dependent Krylov subspace reduction. Journal of Computational Physics, 229(12):4831-1839.
  19. Zaslavsky, M., Druskin, V., and Knizhnerman, L. (2011). Solution of 3D time-domain electromagnetic problems using optimal subspace projection. Geophysics, 76(6):F339-F351.
/content/journals/10.1071/ASEG2018abM1_1E
Loading
  • Article Type: Research Article
Keyword(s): Electromagnetics; Forward modelling; Induced polarization
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error