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Korean Radioactive Waste Society (한국방사성폐기물학회)
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Evaluation of Low or High Permeability of Fractured Rock using Well Head Losses from Step-Drawdown Tests

단계양수시험으로부터 우물수두손실 항을 이용한 단열의 고.저 투수성 평가

  • Received : 2011.10.10
  • Accepted : 2012.02.08
  • Published : 2012.03.30
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Abstract

The equation of the step-drawdown test "$s_w=BQ+CQ^p$" written by Rorabaugh (1953) is suitable for drawdown increased non-linearly in the fractured rocks. It was found that value of root mean square error (RMSE) between observed and calculated drawdowns was very low. The calculated $C$ (well head loss coefficient) and $P$ (well head loss exponent) value of well head losses ($CQ^p$) ranged $3.689{\times}10^{-19}{\sim}5.825{\times}10^{-7}$ and 3.459~8.290, respectively. It appeared that the deeper depth in pumping well the larger drawdowns due to pumping rate increase. The well head loss in the fractured rocks, unlike that in porous media, is affected by properties of fractures (fractures of aperture, spacing, and connection) around pumping well. The $C$ and $P$ value in the well head loss is very important to interpret turbulence interval and properties of high or low permeability of fractured rock. As a result, regression analysis of $C$ and $P$ value in the well head losses identified the relationship of turbulence interval and hydraulic properties. The relationship between $C$ and $P$ value turned out very useful to interpret hydraulic properties of the fractured rocks.

Rorabaugh(1953)에 의해 재정리된 단계양수시험 해석해 $s_w=BQ+CQ^p$는 단열암반대수층에서 비선형으로 증가하는 수위강하에 매우 적합하며, 현장에서 관측된 수위강하 값과 추정된 수위강하 사이의 제곱근 평균제곱오차(RMSE) 값이 매우 낮음을 보여주었다. 우물수두손실($CQ^p$)의 $C$ 값은 $3.689{\times}10^{-19}{\sim}5.825{\times}10^{-7}$, $P$ 값은 3.459~8.290의 범위로 산정되었으며, 지표로부터 하부심도로 내려 갈수록 양수율 증가에 따른 수위강하는 매우 크게 나타났다. 단열암반대수층에서의 우물수두손실은 다공질매질에서와 달리 단열특성(단열의 틈, 간격, 상호 연결성)에 의한 영향으로 나타나므로, 우물수두손실의 $C$ 와 $P$ 값은 단열암 반대수층의 난류구간과 고 저 투수성 단열암반의 특성을 해석하는데 매우 중요하다. 그 결과, 우물수두손실 항의 $C$ 와 $P$ 값에 대한 회귀분석 결과로부터 암반대수층의 난류구간과 수리특성의 관계가 파악되었으며, $C$ 와 $P$ 값의 관계가 단열암반대수층의 수리특성 해석에 있어 매우 유용함을 확인할 수 있었다.

Keywords

References

  1. C. E. Jacob, Drawdown test to determine effective radius of artesian well, Transactions, ASCE, 112, pp. 1047-1070 (1947).
  2. M. I. Rorabaugh, Graphical and theoretical analysis of step-drawdown tests of artesian wells, Proc. Am. Soc. Civ. Eng., 79, 362p (1953).
  3. D. H. Lennox, Analysis and application of stepdrawdown tests, J. Hydraul. div., Am. Soc. Civ. Eng., 92(HY6), pp. 25-47 (1966).
  4. N. T. Sheahan, Type-curve solution of stepdrawdown test, Ground Water, 9(1), pp. 25-29 (1971). https://doi.org/10.1111/j.1745-6584.1971.tb03528.x
  5. Y. K. Birsoy and W. K. Summers, Determination of aquifer parameters from step tests and intermittent pumping data, Ground Water, 18(2), pp. 137-146 (1980). https://doi.org/10.1111/j.1745-6584.1980.tb03382.x
  6. G. P. Kruseman and de N. A. Ridder, Analysis and evaluation of pumping test data, International institute for Land Reclamation and Improvement, Wageningen, the Netherlands, 2nd de. (completely revised), 377p (1991).
  7. W. H. Bierschenk, Determining well efficiency by multiple step-drawdown tests, International Association of Scientific Hydrology, 64, pp. 494-507 (1963).
  8. M. C. Kasenow, Production Well Analysis: New Methods and a computer program in well hydraulics. Water Resources Publications, LLC, Highlands Ranch, Colorado, 355p (1996).
  9. J. W. Labadie, and O. J. Helweg, Step-drawdown test analysis by computer, Ground Water, 13(5), pp. 438-444 (1975). https://doi.org/10.1111/j.1745-6584.1975.tb03611.x
  10. N. T. Sheahan, Discussion of step-drawdown test analysis by computer, Ground Water, 13(5), pp. 445-449 (1975). https://doi.org/10.1111/j.1745-6584.1975.tb03612.x
  11. A. D. Gupta, On analysis of step-drawdown data, Ground Water, 27(6), pp. 874-881 (1989). https://doi.org/10.1111/j.1745-6584.1989.tb01051.x
  12. S. K. Singh, Optimization of confined aquifer parameters from variable rate pump test, J. Hydraul. Eng., 4(1), pp. 61-70 (1998).
  13. S. Shekhar, An approach to interpretation of step drawdown tests, Hydrogeology Journal, 14, pp. 1018-1027 (2006). https://doi.org/10.1007/s10040-005-0016-x
  14. C. T. Miller and W. J. Weber, Rapid solution of the nonlinear step-drawdown equation, Ground Water. 21(5), pp. 584-588(1983). https://doi.org/10.1111/j.1745-6584.1983.tb00765.x
  15. G. J. V. Tonder, J. F. Botha, and J. V. Bosch, A generalised solution for step-drawdown tests including flow dimension and elasticity, Water SA, 27(3), pp. 345-354.
  16. J. Y. Lee, S. H. Song, and K. K. Lee, Effects of Selected Time on Analysis Results in Step-Drawdown Tests, Journal of Korean Society of Soil and Groundwater Environment, 10(2), pp. 59-65 (2005).
  17. J. Y. Lee, Problems in determining optimal discharge using step-drawdown tests, Journal of the Geological Society of Korea, 46(5), pp. 485-495 (2010).
  18. C. W. Lee, D. H. Lee, J. G. Jeong, K. Y. Kim, and Y. J. Kim, Well Loss in Fractured Rock Formation with Radial Flow during Pumping Test, Journal of Korean Society of Soil and Groundwater Environment, 7(4), pp. 17-23 (2002).
  19. S. Y. Chung, B. W. Kim, G.-B. Kim, and H. W. Kweon, Effects of Well Parameters Analysis Techniques on Evaluation of Well Efficiency in Step-Drawdown Test, The Journal of Engineering Geology, 19(1) pp. 71-79 (2009).
  20. K. W. Park, S. H. Ji, Y. K. Kho, G. Y. Kim, and J. K. KIM, Numerical simulation of groundwater flow in LILW Repository site:II. Input parameters for Safety Assessment, Journal of the Korean Radioactive Waste Society, 6(4), pp. 283-296 (2008).
  21. M. Oden, A. Niemi, C.-F. Tsang, and J. Ohman, Regional channelized transport in fractured media with matrix diffusion and linear sorption, Water Resouces Research, 44, W02421,doi:10.1029/2006WR005632 (2008).
  22. Ministry of Construction and Transportation, Korea Water Resources Corporation, and Korea Resources Corporation, Groundwater survey of Cheongwon-Chengju Area, Government Publications Registration Number (1-1500000-001810-01), 7-7 (2006).
  23. Daewoo E&C, Post-construction safety assessment report of underground library at the Busan Branch, the National Archives of Korea near a access tunnel on Gyeongbu KTX train line (Reach 14-2), 752p (2004).
  24. V. Batu, Aquifer Hydraulics- A comprehensive guide to hydrogeologic data analysis, John Weley & sons, New York, pp. 113-627 (1998).
  25. D. K. Todd, Groundwater Hydrology, John Wiley & Sons, New York, pp. 111-163 (1980).
  26. M. K. Jha, A. Kumar, G. Nanda, and G. Bhatt, Evaluation of Traditional and Nontraditional Optimization Techniques for Determining Well Parameters from Step-Drawdown Test Data, Jouranl of Hydrologic Engineering, 11(6), pp. 617-630 (2006). https://doi.org/10.1061/(ASCE)1084-0699(2006)11:6(617)
  27. D. Bourdet, T. M. Whittle, A. A. Douglas, and Y. M. Prirard, A new set of type curves simplifies well test anal;ysisi, World Oil, May 1983, pp. 95-106 (1983).
  28. F. A. Jr. Spane, and S. K. Wurstner, DERIV: A computer program for calculating pressure derivative for use hydraulic test analysis, Groun Water 31(5), pp. 814-822 (1993). https://doi.org/10.1111/j.1745-6584.1993.tb00855.x

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