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http://dx.doi.org/10.7582/GGE.2013.16.3.139

A Scheme for Computing Time-domain Electromagnetic Fields of a Horizontally Layered Earth  

Jang, Hangilro (Department of Energy Resources Engineering, Pukyong National University)
Kim, Hee Joon (Department of Energy Resources Engineering, Pukyong National University)
Publication Information
Geophysics and Geophysical Exploration / v.16, no.3, 2013 , pp. 139-144 More about this Journal
Abstract
A computer program has been developed to estimate time-domain electromagnetic (EM) responses for a onedimensional model with multiple source and receiver dipoles that are finite in length. The time-domain solution can be obtained by applying an inverse fast Fourier transform (FFT) to frequency-domain fields for efficiency. Frequency-domain responses are first obtained for 10 logarithmically equidistant frequencies per decade, and then cubic spline interpolated to get the FFT input. In the case of phases, the phase curve must be made to be continuous prior to the spline interpolation. The spline interpolated data are convolved with a source current waveform prior to FFT. In this paper, only a step-off waveform is considered. This time-domain code is verified with an analytic solution and EM responses for a marine hydrocarbon reservoir model. Through these comparisons, we can confirm that the accuracy of the developed program is fairly high.
Keywords
electromagnetic; time domain; step-off; frequency; phase;
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Times Cited By KSCI : 1  (Citation Analysis)
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1 Kim, H. J., Song, Y., and Lee, K. H., 1997, High-frequency electromagnetic inversion for a dispersive layered earth, J. Geomag. Geoelect., 49, 1439-1450.   DOI   ScienceOn
2 Song, Y., Kim, H. J., and Lee, K. H., 2002, High-frequency electromagnetic impedance method for subsurface imaging, Geophysics, 67, 501-510.   DOI   ScienceOn
3 Lee, K. H., Jang, H., Jang, H., and Kim, H. J., 2011, Sensitivity analysis of marine controlled-source electromagnetic methods to a shallow gas-hydrate layer with 1D forward modeling, Geosci. Jour., 15, 297-303.   DOI
4 Press, W. H., Teukolsky, S. A., Vetterling, W. T., and Flannery, B. P., 1992, Numerical Recipes in Fortran, 2nd ed., Cambridge, 963p.
5 Robinson, E. A., 1967, Multichannel time series analysis with digital computer programs, Holden-Day, 298p.
6 Sorensen, K. I., and Christensen, N. B., 1994, The fields from a finite electrical dipole - A new computational approach, Geophysics, 59, 864-880.   DOI   ScienceOn
7 Spies, B. R., and Frischknecht, F. C., 1991, Electromagnetic sounding, in Nabighian, M. N., ed., Electromagnetic methods in applied geophysics: Applications, Parts A and B, vol. 2, Soc. Expl. Geophys., 285-425.
8 Ward, S. H., and Hohmann, G. W., 1988, Electromagnetic theory for geophysical applications, in Nabighian, M. N., ed., Electromagnetic Methods in Applied Geophysics, vol. 1, Soc. Expl. Geophys., 203-252.
9 Kim, H. J., 2011, A Scheme for compution Primary Fields in Modeling of Marine controlled-Source Electromagnetic Surveys, Geophysics and Geophysical Exploration, 14, 185-190.
10 Kim, H. J., Choi, J. H., Han, N. R., Song, Y. H., and Lee, K. H., 2009, Primary Solution Evaluations for Interpretion Electromagnetic Data, Geophysics and Geophysical Exploration, 12, 361-366.
11 Anderson, W. L., 1989, A hybrid fast Hankel transform algorithm for electromagnetic modeling, Geophysics, 54, 263-266.   DOI
12 Commer, M., and Newman, G., 2004, A parallel finite-difference approach for 3D transient electromagnetic modeling with galvanic sources, Geophysics, 69, 1192-1202.   DOI   ScienceOn
13 Christensen, N. B., 1990, Optimized fast Hankel transform filters, Geophys. Prosp., 38, 545-568.   DOI
14 Christensen, N. B., 1991, Reply to comments by Walter L. Anderson, Geophys. Prosp., 39, 449-450.   DOI
15 Guptasarma, D., and Singh, B., 1997, New digital linear filters for Hankel $J_0$ and $J_1$ transforms, Geophys. Prosp., 45, 745-762.   DOI   ScienceOn
16 Edwards, R. N., Law, L. K., Wolfgram, P. A., Nobes, D. C., Bone, M. N., Trigg, D. F., and DeLaurier, J. M., 1985, First results of the MOSES experiment: Sea sediment conductivity and thickness determination, Bute Inlet, British Columbia, by magnetometric offshore electrical sounding, Geophysics, 50, 153-160.   DOI   ScienceOn
17 Guptasarma, D., 1982, Optimization of shorter digital linear filters for increased accuracy, Geophys. Prosp., 30, 501-514.   DOI
18 Holten, T., Flekkoy, E. G., Singer, B., Blixt, E. M., Hanssen, A., and Maloy, K. J., 2009, Vertical source, vertical receiver, electromagnetic technique for offshore hydrocarbon exploration, First Break, 27, 89-93.
19 Jang, H., Jang, H., Lee, K. H., and Kim, H. J., 2013, Step-off, vertical electromagnetic responses of a deep resistivity layer buried in marine sediments, J. Geophys. Eng., (in print)
20 Johansen, H. K., and Sorensen, K., 1979, Fast Hankel transforms, Geophys. Prosp., 27, 876-901.   DOI
21 Hunziker, J., Slob, E., and Mulder, W., 2011, Effects of the airwave in time-domain marine controlled-source electromagnetics, Geophysics, 76, F251-F261. doi: 10.1190/1.3587222   DOI   ScienceOn