DOI QR코드

DOI QR Code

미고결대수층에서 우물 굴착 및 개량에 의한 대수층의 수리특성 변화

Change of Hydraulic Characteristics due to Well Drilling and Well Development in an Unconsolidated Aquifer

  • 김병우 (한국원자력연구원 방사성폐기물처분연구부) ;
  • 김규범 (한국수자원공사 K-water연구원) ;
  • 김건영 (한국원자력연구원 방사성폐기물처분연구부)
  • Kim, Byung-Woo (Radioactive Waste Disposal Research Division, Korea Atomic Energy Research Institute) ;
  • Kim, Gyoo-Bum (K-water Institute, Korea Water Resources Corporation) ;
  • Kim, Geon-Young (Radioactive Waste Disposal Research Division, Korea Atomic Energy Research Institute)
  • 투고 : 2012.01.25
  • 심사 : 2012.03.05
  • 발행 : 2012.03.30

초록

미고결대수층에서 우물 굴착 시 대수층 교란이 수리특성에 미치는 영향을 파악하기 위하여 우물굴착 이후의 우물개량 공법인 서지블록과 에어서징을 실시하였다. 그리고 우물 굴착 및 개량의 대수층 변화를 비교 분석하기, 위하여 단계 및 장기 양수시험을 수행하였다. 그 결과 우물 굴착 및 개량 이후의 단계양수시험에서 동일 양수율 $700m^3/day$에 대한 수위강하와 비교하였을 때 수위강하는 각각 26.01 m, 21.62 m로 4.39 m정도 감소되었다. 이때 우물특성을 파악하기 위한 우물 굴착 및 개량 이후의 스킨계수는 7.92에서 5.04로 감소되어 우물상태가 개선된 것으로 나타났다. 우물 굴착 및 개량 이후의 장기양수시험에서 양수정을 중심으로 주변 MW-2, 3, 4호정의 투수량계수 범위는 각각 $1.684{\times}10^{-3}{\sim}4.490{\times}10^{-3}m^2/sec$, $4.002{\times}10^{-3}{\sim}4.939{\times}10^{-3}m^2/sec$ 범위로 우물개량 이후의 수리전도도 값이 조금 증가되었으며, MW-1호정은 $1.018{\times}10^{-2}m^2/sec$에서 $6.988{\times}10^{-3}m^2/sec$로 감소되었다. 이는 서징하는 동안 대수층의 공기 차단 및 폐색의 잠재적인 요인으로 인하여 MW-1호정 주변 대수층의 투수성이 미세하게 감소되는 효과로 나타났다. 따라서 미고결대수층에서 우물 굴착 시 미세입자가 양수정 주변의 수리특성에 영향을 미칠 수 있음을 반드시 유의해야 한다.

To investigate the effect of aquifer disturbance on hydraulic properties while well drilling at unconsolidated aquifer, the following tests were conducted: the surge block and air-surging methods, which are well development methods used after well drilling; and step-drawdown tests and constant-rate pumping tests, which are used to assess changes in the aquifer after well drilling and development. The result of step-drawdown tests indicated that drawdown for a pumping-rate of $700m^3/day$ was 21.62 m after well development, decreasing 4.39 m from 26.01 m after well drilling. The skin factor used to identify the well properties decreased from 7.92 after well drilling to 5.04 after well development, respectively, which shows the improvement of well. Constant-rate pumping tests revealed a small increase in aquifer transmissivity after well development at MW-2, -3, and -4, centering around pumping well, from $1.684{\times}10^{-3}{\sim}4.490{\times}10^{-3}m^2/sec$ to $4.002{\times}10^{-3}{\sim}4.939{\times}10^{-3}m^2/sec$. MW-1, however, showed decline in hydraulic conductivity from $1.018{\times}10^{-2}m^2/sec$ to $6.988{\times}10^{-3}m^2/sec$, which was caused by a small decrease of aquifer permeability around monitoring well MW-1 due to latent factor of air interception and clogging in aquifer during surging. This finding indicates that fine particles have an effect on hydraulic properties at unconsolidated aquifers during well drilling; therefore, we consider that well drilling and development have an effect on hydraulic properties.

키워드

참고문헌

  1. 김규범, 김병우, 김성윤, 2010, 충적층 양수정에서 우물 개량을 통한 우물효율의 개선, 지하수토양환경학회지, 15(1), 39-49.
  2. 김규범, 김병우, 신선호, 박준형, 2009, 강변여과수 개발 지역 우물 개량시 철망간 저감 효과, 지질공학회지, 19(3), 389-400.
  3. 김남장, 이규홍, 1964, 한국지질도 영산도폭(1:50,000), 국립지질조사소. 1p.
  4. 김병우, 김규범, 2009, 미고결퇴적층내 양수시험시 관측정 설계가 추정 수리상수에 미치는 영향 분석, 지질학회지, 45(6), 787-797.
  5. 정상용, 김병우, 김규범, 권해우, 2009, 단계양수시험해석시 우물상수 산정 방법이 우물효율에 미치는 영향, 지질공학회지, 19(1), 71-79.
  6. Charles A., Kaehler C.A. and Hsieh P.A., 1994, Hydraulic properties of a fractured-rock aquifer, Lee valley, San Diego County, California, prepared in cooperation wity San Diego county Department of Planning and Land Use, U.S. Geological survey water-supply paper 2394. 26-32.
  7. Chugh, C.P., 1985, Manual of Drilling Techology, A.A. Balkema, 567p.
  8. Clark, L., and Turner, P.A., 1983, Experiments to Assess the Hydraulic Efficiency, Ground Water, 12(3), 270-281.
  9. Davis, R., 2003, Aquifer analysis and proper well development to maximize pumping capacity in alluvial wells, Water Well Journal, 57(2), 34-37.
  10. Driscoll, F.G., 1986, Groundwater and Wells, 2nd Edition, Johnson Division, St. Paul, MN., 1108p.
  11. Earlougher, R. C., Jr., 1977, Advances in Well Test Analysis, Monograph Series, 5, 264p.
  12. Furui, K., 2004, A comprehensive skin factor model for well completions based on finite element simulations, Ph.D. thesis, University of Texas at Austin, 169p.
  13. Hawkins, M. F., Jr., 1956, A note on the Skin Effect, Trans., AIME 207, 356-357.
  14. Hix, G.L., 1993, Monitoring well development : Tools and techniques, Water Well Journal, 47(6), 52-57.
  15. Houben, G. and Treskatis, C., 2007, Water Well; Rehabilition and Reconstruction, McGraw-Hill Companies, Inc., 391p.
  16. Jacob, C.E., 1947, Drawdown test to determine effective radius of artesian well, Transactions, ASCE, 112, 1047-1070.
  17. Kasenow, M.C., 1996, Production Well Analysis: New Methods and a computer program in well hydraulics. Water Resources Publications, LLC, Highlands Ranch, Colorado, 355p.
  18. Kroening, D.E., Snipes, D.S., Brame, S.E., Hodges, R.A., Price, V. and Temples, T.J., 1996, The rehabilitation of monitoring wells clogged by calcite precipitation and drilling mud, Ground Water Monitoring and Remediation, 16(2), 114-123. https://doi.org/10.1111/j.1745-6592.1996.tb00131.x
  19. Labadie, J.W. and Helweg, O.J., 1975, Step-drawdown test analysis by computer, Ground Water, 13(5), 438-444. https://doi.org/10.1111/j.1745-6584.1975.tb03611.x
  20. Neuman, S.P., 1974, Effect of partial penetration on flow in unconfined aquifers considering delayed gravity response, Water Resources Research, 10(2), 303-312. https://doi.org/10.1029/WR010i002p00303
  21. Novakowski, K.S., 1990, Analysis of aquifer tests conducted in fractured rock: A review of the physical background and the design of a computer program for generating type curves, Ground water 28(1), 99-105. https://doi.org/10.1111/j.1745-6584.1990.tb02233.x
  22. Rosberg, J.E. and Bjelm, L., 2009, Well development by jetting using coiled tubing and simultaneous pumping. Ground Water, doi: 10.1111/j.1745-6584.2009.00588.x. 1-6.
  23. Roscoe Moss Company, 1990, Handbook of Ground Water Development, John Wiley and Sons, New York, 512p.
  24. Sterrett, R.J., 2007, Groundwater and Wells, 3rd Edition, Johnson Screens, New Brighton, Minnesota, 812p.
  25. Theis, C.V., 1935, The relation between the lowering of the piezometric surface and the rate and duration of discharge of a well using groundwater storage, Am. Geophys. Union Trans., Vol.16, 519-524. https://doi.org/10.1029/TR016i002p00519
  26. Wendling, G., Chapuis, R.P. and Gill, D.E., 1997, Quantifying the effects of well development in unconsolidated material, Ground Water, 35, 387-399. https://doi.org/10.1111/j.1745-6584.1997.tb00097.x

피인용 문헌

  1. Estimation of Drilling Velocity for Horizontal Wells Based on Alluvial Sediment Characteristics vol.25, pp.2, 2015, https://doi.org/10.9720/kseg.2015.2.273