DOI QR코드

DOI QR Code

시간영역 유도분극 자료의 Cole-Cole 역산

Spectral Inversion of Time-domain Induced Polarization Data

  • 김연정 (강원대학교 지구물리학과) ;
  • 조인기 (강원대학교 지질, 지구물리학부)
  • Kim, Yeon-Jung (Department of Geophysics, Kangwon National University) ;
  • Cho, In-Ky (Division of Geology and Geophysics, Kangwon National University)
  • 투고 : 2021.09.30
  • 심사 : 2021.11.22
  • 발행 : 2021.11.30

초록

시간영역 유도분극 탐사 자료로부터 Cole-Cole 변수를 추정하는 2차원 역산법을 개발하였다. 모든 유도분극 과도 전위 자료를 역산하여 전기비저항, 충전성, 완화 시간 및 주파수 승수 등의 2D Cole-Cole 변수를 추정하였다. 개발된 역산법은 2단계로 구성된다. 우선 음의 겉보기 충전성 문제를 피하기 위하여 측정된 유도분극 반응을 전류 주입 중 겉보기 전기비저항으로 변환하였다. 1단계 역산에서는 시간에 따라 항상 증가하는 전기비저항을 추정하는 4차원 역산을 통하여 각 역산 블록에서의 전기비저항 시계열 모델을 구축하였다. 2단계 역산에서는 4차원 역산에서 얻어진 전기비저항 시계열 자료를 역산하여 Cole-Cole 변수를 추정하였다. 이때 격자 탐색법을 통하여 참값에 근접한 초기 모델을 설정하는 방법을 통하여 신속한 역산이 가능하였다. 마지막으로 수치 자료에 대한 역산 실험을 통해 개발된 알고리즘이 Cole-Cole 지하 모델을 효과적으로 영상화할 수 있음을 확인하였다.

We outline a process for estimating Cole-Cole parameters from time-domain induced polarization (IP) data. The IP transients are all inverted to 2D Cole-Cole earth models that include resistivity, chargeability, relaxation time, and the frequency exponent. Our inversion algorithm consists of two stages. We first convert the measured voltage decay curves into time series of current-on time apparent resistivity to circumvent the negative chargeability problem. As a first step, a 4D inversion recovers the resistivity model at each time channel that increases monotonically with time. The desired intrinsic Cole-Cole parameters are then recovered by inverting the resistivity time series of each inversion block. In the second step, the Cole-Cole parameters can be estimated readily by setting the initial model close to the true value through a grid search method. Finally, through inversion procedures applied to synthetic data sets, we demonstrate that our algorithm can image the Cole-Cole earth models effectively.

키워드

참고문헌

  1. Binley, A., Slater, L., Fukes, M., and Cassiani, G., 2005, The relationship between spectral induced polarization and hydraulic properties of saturated and unsaturated sandstone, Water Resour. Res., 41, doi:10.1029/2005WR004202
  2. Borner, F. D., Schopper, J. R., and Weller, A., 1996, Evaluation of transport and storage properties in the soil and groundwater zone from induced polarization measurements 1, Geophys. Prospect., 44(4), 583-601, doi:10.1111/j.1365-2478.1996.tb00167.x
  3. Cho, I. K., and Jeong, D. B., 2018, 4D inversion of resistivity monitoring data with focusing model constraint, Geophys. and Explor. Geophys., 21(3), 139-149 (in Korean with English abstract). https://doi.org/10.7582/GGE.2018.21.3.139
  4. Cho, I. K., and Kim, Y. J., 2021, Nonlinear inversion of time-domain induced polarization data including negative apparent chargeability data, Geophys. and Geophys. Explor., 24(4), 139-148 (in Korean with English abstract).
  5. Cole, K. S., and Cole, R. H., 1941, Dispersion and absorption in dielectrics: 1. Alternating current fields, J. Chem. Phys., 9, 341-351, https://doi.org/10.1063/1.1750906
  6. Commer, M., and Newman, G. A., 2008, New advances in three-dimensional controlled-source electromagnetic inversion, Geophys. J. Int., 172, 513-535, https://doi.org/10.1111/j.1365-246X.2007.03663.x
  7. Dahlin, T., Bernstone, C., and Loke, M. H., 2002, A 3-D resistivity investigation of a contaminated site at Lernacken, Sweden, Geophysics, 67, 1692-1700, https://doi.org/10.1190/1.1527070
  8. Dias, C. A., 2000, Developments in a model to describe low-frequency electrical polarization of rocks, Geophysics, 65(2), 437-451, https://doi.org/10.1190/1.1444738
  9. Fiandaca, G., Auken, E., Christiansen, A. V., and Gazoty, A., 2012, Time-domain induced polarization: Full-decay forward modeling and 1D laterally constrained inversion of Cole-Cole parameters, Geophysics, 77(3), E213-E225, https://doi.org/10.1190/geo2011-0217.1
  10. Fiandaca, G., Madsen, L. M., and Maurya P. K., 2018, Reparameterisations of the Cole-Cole model for improved spectral inversion of induced polarization data, Near surf. Geophys., 16, 385-399, https://doi.org/10.3997/1873-0604.2017065
  11. Fiandaca, G., Ramm, J., Binley, A., Gazoty, A., Christiansen, A. V., and Auken, E., 2013, Resolving spectral information from time domain induced polarization data through 2-D inversion, Geophys. J. Int., 192, 631-646, https://doi.org/10.1093/gji/ggs060
  12. Honig, M., and Tezkan, B., 2007, 1D and 2D Cole-Cole-inversion of time-domain induced-polarization data, Geophys. Prospect., 55, 117-133, https://doi.org/10.1111/j.1365-2478.2006.00570.x
  13. Karaoulis, M. C., Kim, J. H., and Tsourlos, P. I., 2011, 4D active time constrained resistivity inversion, J. Appl. Geophys., 73, 25-34, https://doi.org/10.1016/j.jappgeo.2010.11.002
  14. Kemna, A., 2000, Tomographic Inversion of Complex Resistivity-Theory and Application, Ph.D. thesis, Der Andere Verlag, Osnabruck, Germany, https://www.scirp.org/(S(vtj3fa45qm1ean45wffcz5%205))/reference/referencespapers.aspx?referenceid=1289409
  15. Kemna, A., Binley, A., Ramirez, A., and Daily, W., 2000, Complex resistivity tomography for environmental applications, Chem. Eng. J., 77, 11-18, doi:10.1016/S1385-8947(99)00135-7
  16. Kim, B., Nam, M. J., and Kim, H. J., 2018, Inversion of time-domain induced polarization data based on time-lapse concept, J. Appl. Geophys., 152, 26-37, https://doi.org/10.1016/j.jappgeo.2018.03.010
  17. Kim, J. H., Supper, R., Tsourlos, P., and Yi, M. J., 2013, Four dimensional inversion of resistivity monitoring data through Lp norm minimizations, Geophys. J. Int., 195, 1640-1656, https://doi.org/10.1093/gji/ggt324
  18. Kim, H. J., Song, Y. H., and Lee, K. H., 1999, Inequality constraint in least squares inversion of geophysical data, Earth Planets Space, 51, 255-259, doi:10.1186/BF03352229
  19. Kim, Y. J., and Cho, I. K., 2021, Extraction of Cole-Cole parameters from time-domain induced polarization data, Geophys. and Geophys. Explor., 24(4), 164-170 (in Korean with English abstract).
  20. Oldenburg, D. W., and Li., Y., 1994, Inversion of induced polarization data, Geophysics, 59, 1327-1341, https://doi.org/10.1190/1.1443692
  21. Pelton, W. H., Ward, S. H., Hallof, P. G., Sill, W. R., and Nelson, P. H., 1978, Mineral discrimination and removal of inductive coupling with multifrequency IP, Geophysics, 43, 588-609, https://doi.org/10.1190/1.1440839
  22. Seigel, H. O., 1959, Mathematical formulation and type curves for induced polarization, Geophysics, 24, 547-565, https://doi.org/10.1190/1.1438625
  23. Tarasov, A., and Titov, K., 2007, Relaxation time distribution from time domain induced polarization measurements, Geophys. J. Int., 170, 31-43, https://doi.org/10.1111/j.1365-246X.2007.03376.x
  24. Van Voorhis, G. D., Nelson, P. H., and Drake, T. L., 1973, Complex resistivity spectra of porphyry copper mineralization, Geophysics, 38, 49-60, https://doi.org/10.1190/1.1440333
  25. Weller, A., Seichter, M., and Kampke, A., 1996, Induced-polarization modelling using complex electrical conductivities, Geophys. J. Int., 127, 387-398, https://doi.org/10.1111/j.1365-246X.1996.tb04728.x
  26. Yuval, and Oldenburg, D. W., 1997, Computation of Cole-Cole parameters from IP data, Geophysics, 62, 436-448, https://doi.org/10.1190/1.1444154
  27. Zarif, F., Kessouri, P., and Slater, L., 2017, Recommendations for field-scale induced polarization (IP) data acquisition and interpretation, J. Envion. Eng. Geophys., 22(4), 395-410, doi: 10.2113/JEEG22.4.395