The Journal of Engineering Geology (지질공학)

The Korean Society of Engineering Geology (대한지질공학회)
권호 표지

Groundwater Flow Analysis in Fractured Rocks Using Zonal Pumping Tests and Water Quality Logs

구간양수시험과 수질검층자료에 의한 균열암반내 지하수 유동 분석

  • Hamm, Se-Yeong (Division of Earth Environmental System, Pusan National University) ;
  • Sung, Ig-Hwan (Groundwater & Geothermal Resources Division, Korea Institute of Geoscience & Mineral Resources) ;
  • Lee, Byeong-Dae (Groundwater & Geothermal Resources Division, Korea Institute of Geoscience & Mineral Resources) ;
  • Jang, Seong (Korea Rural Community & Agriculture Corporation) ;
  • Cheong, Jae-Yeol (Division of Earth Environmental System, Pusan National University) ;
  • Lee, Jeong-Hwan (Division of Earth Environmental System, Pusan National University)
  • 함세영 (부산대학교 지구환경시스템학부) ;
  • 성익환 (한국지질자원연구원 지하수지열연구부) ;
  • 이병대 (한국지질자원연구원 지하수지열연구부) ;
  • 장성 (한국농촌공사) ;
  • 정재열 (부산대학교 지구환경시스템학부) ;
  • 이정환 (부산대학교 지구환경시스템학부)
  • Published : 2006.12.30
Download PDF
⟨ Previous Next ⟩

Abstract

This study aimed to recognize characteristics of groundwater flow in fractured bedrocks based on zonal pump-ing tests, slug tests, water quality logs and borehole TV camera logs conducted on two boreholes (NJ-11 and SJ-8) in the city of Naju. Especially, the zonal pumping tests using sin91e Packer were executed to reveal groundwater flow characteristics in the fractured bedrocks with depth. On borehole NJ-11, the zonal pumping tests resulted in a flow dimension of 1.6 with a packer depth of 56.9 meters. It also resulted in lower flow dimensions as moving to shallower packer depths, reaching a flow dimension of 1 at a 24 meter packer depth. This fact indicates that uniform permissive fractures take place in deeper zones at the borehole. On borehole SJ-8, a flow dimension of 1.7 was determined at the deepest packer level (50 m). Next, a dimension of 1.8 was obtained at 32 meters of packer depth, and lastly a dimension of 1.4 at 19 meters of packer depth. The variation of flow dimension with different packer depths is interpreted by the variability of permissive fractures with depth. Zonal pumping tests led to the utilization of the Moench (1984) dual-porosity model because hydraulic characteristics in the test holes were most suitable to the fractured bedrocks. Water quality logs displayed a tendency to increase geothermal temperature, to increase pH and to decrease dissolved oxygen. In addition, there was an increasing tendency towards electrical conductance and a decreasing tendency towards dissolved oxygen at most fracture zones.

본 연구의 목적은 나주시에 위치하는 시추공 NJ-11호공과 SJ-8호공에서 구간양수시험, 순간충격시험, 수질검층, 공내 TV검층을 실시하여 균열암반내에서 심도에 따른 지하수 유동 특성을 파악하는데 있었다. 본 연구에서는 특히 깊이에 따른 균열암반의 지하수 유동 특성 변화를 규명하기 위하여 단일팩커를 사용한 구간양수시험을 실시하였다. 구간양수시험 결과, NJ-11호공에서는 팩커 설치심도가 가장 깊을 때(56.9 m) 1.6차원정도의 유동차원을 보이고 팩커 설치심도가 얕아 질수록 유동차원이 감소하여 팩커 설치심도 24 m에서는 1차원을 나타내었다. 이는 NJ-11호공에서는 하부에 유동성 균열이 더 균일하게 발달되어 있음을 지시한다. 한편 SJ-8호공에서는 팩커 설치심도가 가장 깊은 50 m 심도에서 1.7차원정도이고, 팩커 설치심도 32 m에서는 1.8차원 그리고 팩커 설치심도 19 m에서는 1.4차원을 나타내고 있다. 이와 같이 팩커 심도에 따라서 유동차원이 달라지는 것은 균열암반에서 심도에 따라 유동성 균열의 발달정도가 달라지기 때문으로 해석된다 구간양수시험분석에 의하면, 균열암반의 일반적인 수리적 특성을 잘 대변하는 Moench(1984)의 이중공극모델이 대체로 잘 들어맞는다. 수질검층에 의하면, 심도가 깊어질수록 지온이 증가하고 물-광물반응에 의해서 pH가 높아지며, 지하수흐름에 따라 용존산소량은 감소하는 일반적인 경향성을 보여주고 있다. 그리고 대부분의 균열대 구간에서 전기전도도가 증가하고, 용존산소량이 감소하는 경향성을 보여주었다.

Keywords

References

  1. 김용준, 박영석, 주승환, 오민수, 박재봉, 1991, 옥천지향 사대 동남대에서의 화성활동(III) (나주-남창지역을 중심으로), 광산지질, 24(3), pp.361-376
  2. 한국지질자원연구원, 환경부, 2003, 폐공을 이용한 도심 지역 지하수 환경성 복원기술개발, 567p
  3. 함세영, 1997, 일정수두 상부경계를 가지는 이중공극 대수층내 부정류에 관한 프락탈모델, 지하수환경, 4(2), pp.95-102
  4. Acuna, J.A. and Yortsos, Y.C., 1995, Application of fractal geometry to the study of networks of fractures and their pressure transient, Water Resources Research, 31(3), pp.527-540 https://doi.org/10.1029/94WR02260
  5. Allegre, C.J. Le Mouel, J.-L., and Provost, A., 1982, Scaling rules in rock fractures and posible implications for earthquake prediction, Nature, 297, pp.47- 49 https://doi.org/10.1038/297047a0
  6. Anderson, J., Shapiro, A.M., and Bear, J., 1984, A stochastic model of a fractured rock conditioned by measured information, Water Resour. Res., 20(1), pp.79-88 https://doi.org/10.1029/WR020i001p00079
  7. Barenblatt, G.E., Zheltov, I.P., and Kochina, I.N., 1960, Basic conccepts in the theory of homogeneous liquids in fissured rocks, Jour. Appl. Math. Mech, pp.1286-1303
  8. Barker, J.A, 1998, A generalized radial flow model for pumping tests in fractured rock, Water Resources Research, 24, pp.1796-1804 https://doi.org/10.1029/WR024i010p01796
  9. Barnsley, M.F., 1998, Fractals everywhere, Academic, San Diego, Calif., 530p
  10. Boulton, N.S. and Streltsova, T.D., 1977, Unsteady flow to a pumped well in a fissured water-bearing formation, Jour. Hydr., 35, pp.257-269 https://doi.org/10.1016/0022-1694(77)90005-1
  11. Cacas, M.C., Ledoux, E., de Marsily, G., Tillie, B., Barbreau, A., Durand, E., Feuga, B., and Peaudecerf, P., 1990a, Modeling fracture flow with a stochastic discrete fracture network : calibration and validation, 1. The flow model, Water Resour. Res. 26(3), pp.479- 489
  12. Cacas, M.C., Ledoux, E., de Marsily, G., Barbreau, A., Calmels, P., Gaillard, B., and Margritta, R., 1990b, Modeling fracture flow with a stochastic discrete fracture network : calibration and validation, 2. The transport model, Water Resour. Res., 26(3), pp.491- 500
  13. Chang, J. and Yortsos, Y.C., 1988 Pressure transient analysis of fractal reservoirs, SPE 18170, pp.1-14
  14. Gringarten, A.C. and Ramey, H.J., 1974, Unsteady state pressure distributions created by a well with a single horizontal frature, partial penetration or restricted entry, Soc. Petro. Engrs. J., pp.413-426
  15. Gringarten, A.C. and Witherspoon, P.A., 1972, A method of analyzing pump test data from fratured aquifers, Int. Soc. Rock Mechanics and Int. Assoc. Eng. Geol., Proc. Symp. Rock Mechanics, Stuttgart, 3-B, pp.1-9
  16. Hamm, S.Y. and Bidaux, P., 1996, Dual-porosity fractal models for transient flow analysis in fissured rocks, Water Resources Research, 32(9), pp.2733-2745 https://doi.org/10.1029/96WR01464
  17. Hamm, S.Y. and Bidaux, P., 1994a, Ecoulements tran sitoires en géométric fractale avec drainance : théorie et application, C. R. Acad. Sci. Paris, serie II, 318(2), pp.227-233
  18. Hamm, S.Y. and Bidaux, P., 1994b, Stationary dualporosity fractal model of groundwater flow in fissured aquifers, The Jour. Eng. Geol., 4(2), pp.127- 138
  19. Hantush, M.S., 1960, Modification of the theory of leaky aquifers, Jour. of Geophy. Res., 65(11), 3713-3725 https://doi.org/10.1029/JZ065i011p03713
  20. Hantush, M.S., 1962, Flow of groundwater in sands of nonuniform thickness; 3. Flow to wells, Jour. Geophys. Res. 67(4), pp.1537-1534
  21. Hantush, M.S. and Jacob, C.E., 1955, Non-steady radial flow in an infinite leaky aquifer, Am. Geophys. Union Trans., 36, pp.95-100 https://doi.org/10.1029/TR036i001p00095
  22. Jones, M.A., 2001, Discrete fracture network modeling to differentiate conceptual models of fluid flow, New approaches characterizing groundwater flow, Proceedings of the 31 International Association of Hydrogeologists Congress, Munuch, Germany, pp.835-837
  23. Kazemi, H., 1969, Pressure transient analysis of naturally fractured reservoir, Trans. AIME, 256, pp.451- 461
  24. Long, J.C.S. and Billaux, D.M., 1987, From field data to fracture network modeling an example incorporating spatial structure, Water Resour. Res., 23(7), pp.1201- 1216 https://doi.org/10.1029/WR023i007p01201
  25. Long, J.C.S., Gilmour, P., and Witherspoon, P.A., 1985, A model for steady fluid flow in random three-dimensional networks of disc-shaped fractures, Water Resour. Res., 21(8), pp.1105-1115 https://doi.org/10.1029/WR021i008p01105
  26. Moench, A.F., 1984, Double-porosity models for a fissured groundwater reservoir with fracture skin, Water Resour. Res., 20, pp.831-846 https://doi.org/10.1029/WR020i007p00831
  27. Moench, A.F., 1985, Transient flow to a large-diameter well in an aquifer with storative semiconfining layers, Water Resources Research, 21(8), pp.1121-1131 https://doi.org/10.1029/WR021i008p01121
  28. Neuman, S.P. and Witherspoon, P.A., 1969, Theory of flow in a confined two aquifer system, Water Resources Research, 5(4), pp.803-816 https://doi.org/10.1029/WR005i004p00803
  29. Papadopulos, I.S. and Cooper, H.H., 1967, Drawdown in a well of large diameter, Water Resources Research, 3, pp.241-244 https://doi.org/10.1029/WR003i001p00241
  30. Sahimi, M., 1995, Flow and transport in porous media and fractured rock, VCH, 482p
  31. Theis, C.V., 1935, The lowering of the piezometer surface and the rate and discharge of a well using groundwater storage, Transaction, American Geophysical Union, 16, pp.519-524 https://doi.org/10.1029/TR016i002p00519
  32. Thomas, A., 1987, Structure fractale de l'architecture des champs de fractures en milieu rocheux, C. R. Acad. Sci. Paris, 304, Ser. 2, pp.181-186
  33. Velde, B., Dubois, J., Moore, D., and Touchard, J., 1991, Fractal patterns of fractures in granites, Earth Planet. Sci. Lett., 104, pp.25-35 https://doi.org/10.1016/0012-821X(91)90234-9
  34. Warren, J.E. and Root, P.J., 1963, The behavior of naturally fractured reservoirs, Soc. Pet. Engr. Jour., pp.245-255