Geophysics and Geophysical Exploration (지구물리와물리탐사)

Korean Society of Earth and Exploration Geophysicists (한국지구물리·물리탐사학회)
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Monitoring $CO_2$ injection with cross-hole electrical resistivity tomography

시추공간 전기비저항 토모그래피를 이용한 $CO_2$ 주입 모니터링

  • Christensen, N.B. (Cooperative Research Centre for Greenhouse Gas Technologies CSIRO Petroleum) ;
  • Sherlock, D. (Cooperative Research Centre for Greenhouse Gas Technologies CSIRO Petroleum) ;
  • Dodds, K. (Cooperative Research Centre for Greenhouse Gas Technologies CSIRO Petroleum)
  • Published : 2006.02.28
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Abstract

In this study, the resolution capabilities of electrical resistivity tomography (ERT) in the monitoring of $CO_2$ injection are investigated. The pole-pole and bipole-bipole electrode configuration types are used between two uncased boreholes straddling the $CO_2$ plume. Forward responses for an initial pre-injection model and three models for subsequent stages of $CO_2$ injection are calculated for the two different electrode configuration types, noise is added and the theoretical data are inverted with both L1- and L2-norm optimisation. The results show that $CO_2$ volumes over a certain threshold can be detected with confidence. The L1-norm proved superior to the L2-norm in most instances. Normalisation of the inverted models with the pre-injection inverse model gives good images of the regions of changing resistivity, and an integrated measure of the total change in resistivity proves to be a valid measure of the total injected volume.

이 연구에서는 $CO_2$ 주입 모니터링에서의 전기비저항 토모그래피(ERT)의 분해능에 대해 조사한다. $CO_2$ 주입체 양쪽의 케이싱 없는 시추공에서 단극자 및 양극자 전극 배열이 사용된다. 주입 전 및 주입에 따른 3단계 모델에 대한 반응이 계산되고, 잡음이 더해진 후의 이론 값들이 L1 과 L2 norm을 사용해 역산된다. 역산결과는 어느 정도 수준이상의 $CO_2$ 부피가 확실히 감지됨을 보여준다. 대부분의 경우에 L1 norm의 경우가 L2에 비해 우월함이 판명되었다. 역산 결과를 주입 전 모델의 역산결과로 정규화하면 전기비저항이 변화하는 부분의 훌륭한 영상을 보여주며, 비저항의 전체적인 변화를 통합해서 판단하면 전체 주입된 부피에 대한 타당한 측정이 이루어짐이 입증된다.

Keywords

References

  1. Barker, R., and Moore, J., 1998, The application of time-lapse electrical tomography in groundwater studies: The Leading Edge, 17, 1454-1458 https://doi.org/10.1190/1.1437878
  2. Daily, w., and Ramirez, A.L., 2000, Electrical imaging of engineered hydraulic barriers: Geophysics, 65, 83-94 https://doi.org/10.1190/1.1444728
  3. Hoversten, G.M., Grillo, R., Washbourne, J., and Daley, T.M., 2003, Pressure and fluid saturation prediction in a multicomponent reservoir using combined seismic and electromagnetic imaging: Geophysics, 68, 1580-1591 https://doi.org/10.1190/1.1620632
  4. Loke, M.H., and Barker, R.D., 1996, Practical techniques for 3-D resistivity surveys and data inversion: Geophysical Prospecting, 44, 499-523 https://doi.org/10.1111/j.1365-2478.1996.tb00162.x
  5. Loke, M.H., 1999. Tune-lapse resistivity imaging inversion: Proceedings of the 5th Meeting of the Environmental and Engineering Geophysical Society European Section
  6. Newmark, R., Daily, w., and Ramirez, A., 1999, Electrical resistance tomography using steel cased boreholes as electrodes: 69th Annual International Meeting of the Society of Exploration Geophysicists, Expanded Abstracts, 18, 327
  7. Sasaki, Y., 1992, Resolution of resistivity tomography inferred from numerical simulation: Geophysical Prospecting, 40, 453-464 https://doi.org/10.1111/j.1365-2478.1992.tb00536.x
  8. Sherlock, D.H., Toomey, A., Hoversten, G.M., Gasperikova, E., and Dodds, K.J., 2006, Gravity monitoring of $CO_2$, storage in a depleted gas field: A sensitivity study: Exploration Geophysics, 37, (this issue)
  9. Siggins, A.E, 2006, Velocity-effective pressure response of $CO_2$ saturated sandstones: Exploration Geophysics, 37, (this issue)
  10. Singer, B.S., and Dodds, K., 2004, Monitoring electrical properties of rocks in target zone of $CO_2$ , sequestration site: 17th Geophysical Conference and Exhibition of the Australian Society of Exploration Geophysicists, Expanded Abstracts
  11. Sugimoto, Y., 1999, Shallow high-resolution 2-D and 3-D electrical crosshole imaging: The Leading Edge, 18,1425-1428 https://doi.org/10.1190/1.1438244
  12. Wilt, M.J., Alumbaugh, D.L., Morrison, RE, Becker, A., Lee, KH., and Deszcz-Pan, M., 1995, Crosswell electromagnetic tomography: System design considerations and field results: Geophysics, 60, 871-885 https://doi.org/10.1190/1.1443823
  13. Wilt, M.J., and Alumbaugh, D.L., 1998, Electromagnetic methods for development and production: State of the art: The Leading Edge, 17,487 https://doi.org/10.1190/1.1437997
  14. Zhou, B., and Greenhalgh, S.A., 2000, Cross-hole resistivity tomography using different electrode configurations: Geophysical Prospecting, 48, 887-912 https://doi.org/10.1046/j.1365-2478.2000.00220.x