Abstract
There are multiple flow paths with different flow directions in fracture intersections. A general flow model synthetically describing the nonlinear flow behavior of multiple flow paths in different directions in two-dimensional fracture intersections was proposed for the analysis of fluid flow in rock fracture networks. The flow behavior of seven typical fracture intersection models, according to a geological investigation, was simulated. Through numerical simulations and experimental observations, it was validated that the flow model was capable of describing the nonlinear flow behavior in each flow direction in the fracture intersections at the same time. In this flow model, the coefficient matrices include linear coefficients for each fracture branch and nonlinear coefficients for each flow path. The relations between the hydraulic pressure drops and the flow rates reflect the influence of intersection configurations and flow directions on flow behavior in the fracture intersections. Based on the flow model and corresponding non-Darcy effect factor for fracture intersections, the critical Reynolds numbers to describe the transition of the flow regime in fracture intersections were determined and found to range from 51 to 105. Furthermore, the transition of the flow regime in the fracture intersections calculated with the proposed model was found to be closely related to the evolution of microscopic flow structures in the numerical simulations.
Résumé
Il existe plusieurs chemins d’écoulement avec différentes directions d’écoulement, au sein des intersections de fractures. Un modèle général d’écoulement, décrivant de manière synthétique le comportement non linéaire de l’écoulement pour plusieurs chemins d’écoulement et différentes directions d’écoulement, au sein d’intersections bi-dimensionnelles de fractures, a été proposé pour l’analyse de l’écoulement d’un fluide dans des réseaux de fractures en milieu rocheux. Le comportement de l’écoulement de sept modèles type d’intersections de fractures, définis d’après une reconnaissance géologique, a été simulé. Grâce à des simulations numériques et à des observations expérimentales, il a été validé que le modèle d’écoulement est capable de décrire le comportement non linéaire de l’écoulement dans chaque direction d’écoulement en même temps au sein des intersections de fractures. Dans ce modèle d’écoulement, les matrices de coefficient comprennent des coefficients linéaires pour chaque branche de la fracture et des coefficients non linéaires pour chaque chemin d’écoulement. Les relations entre les pertes de charge hydraulique et les débits d’écoulement reflètent l’incidence de la configuration des intersections et de la direction de l’écoulement sur le comportement de l’écoulement au sein des intersections de fractures. Sur la base du modèle d’écoulement et du facteur de non-effet de Darcy correspondant appliqué aux intersections de fractures, les nombres de Reynolds critiques décrivant la diffusion du régime d’écoulement au sein des intersections de fractures ont été calculés, ils se situaient entre 51 et 105. En outre, la transition du régime d'écoulement dans les intersections de fractures calculée avec le modèle proposé s'est avérée être étroitement liée à l'évolution des structures d'écoulement microscopiques dans les simulations numériques.
Resumen
En las intersecciones de fracturas existen múltiples trayectorias con diferentes direcciones de flujo. Se propuso un modelo general de flujo que describe sintéticamente el comportamiento no lineal de múltiples trayectorias en diferentes direcciones en intersecciones de fracturas bidimensionales para el análisis del flujo de fluidos en redes de fracturas de rocas. Se simuló el comportamiento del flujo de siete modelos típicos de intersecciones de fractura, según una investigación geológica. Mediante simulaciones numéricas y observaciones experimentales, se validó que el modelo de flujo era capaz de describir el comportamiento no lineal en cada dirección de flujo en las intersecciones de fractura al mismo tiempo. En este modelo, las matrices incluyen coeficientes lineales para cada rama de la fractura y coeficientes no lineales para cada trayectoria de flujo. Las relaciones entre las caídas de presión hidráulica y los caudales reflejan la influencia de las configuraciones de las intersecciones y las direcciones en el comportamiento del flujo en las intersecciones de las fracturas. Basándose en el modelo de flujo y en el correspondiente factor de efecto no Darcy para las intersecciones de fractura, se determinaron los números de Reynolds críticos para describir la transición del régimen de flujo en las intersecciones de fractura y se encontró que oscilaban entre 51 y 105. Además, se comprobó que la transición del régimen en las intersecciones de fractura calculada con el modelo propuesto estaba estrechamente relacionada con la evolución de las estructuras de flujo microscópicas en las simulaciones numéricas.
摘要
裂隙交叉处存在多条不同流向的渗流路径。本文提出了一种综合描述二维交叉裂隙中不同流动方向的多个渗流路径的非线性渗流特性的一般模型, 可用于分析岩石裂缝网络中的流体流动。根据地质调查, 模拟了七个典型交叉裂隙模型的流渗流特性。通过数值模拟和实验观察, 验证了该渗流模型能够同时描述交叉裂缝中各个流动方向的非线性渗流特性。在这个渗流模型中, 系数矩阵包括每个裂缝缝分支上的线性系数和每个渗流路径上的非线性系数。水力压降和流速之间的关系反映了交叉处构和流动方向对交叉裂缝渗流的影响。基于裂流模型和相应的非达西效应因子, 确定了描述裂隙交叉处流态转变的临界雷诺数, 发现其范围是从 51 到 105。 此外还发现, 采用所提模型计算的裂隙交叉处流态转变与数值模拟中微观流动结构的演变密切相关。
Resumo
Existem vários caminhos de fluxo com diferentes direções em interseções de fratura. Um modelo de fluxo geral que descreve sinteticamente o comportamento do fluxo não linear de múltiplos caminhos de fluxo em diferentes direções em interseções de fratura bidimensional foi proposto para a análise de fluxo de fluido em redes de fraturas de rochas. O comportamento do fluxo de sete modelos típicos de intersecção foi simulado de acordo com a investigação geológica. Por meio de simulações numéricas e observações, foi validado que o modelo de fluxo é capaz de descrever ao mesmo tempo o comportamento não linear em cada direção de fluxo nas intersecções de fratura. Neste modelo de fluxo, as matrizes de coeficientes incluem coeficientes lineares para cada ramo de fratura e coeficientes não lineares para cada caminho de fluxo. As relações entre as quedas de pressão hidráulica e as taxas de fluxo refletem a influência das configurações das interseções e as direções dos fluxos no comportamento do fluxo nas intersecções de fraturas. Baseado no modelo de fluxo e no fator de efeito não-Darcyano para intersecções de fratura, os números críticos de Reynolds para descrever a transição do regime de fluxo na intersecção de fratura foram determinados e variam de 51 a 105. Além disso, a transição do regime de fluxo fraturado na interseção da fratura calculado com o modelo proposto mostrou-se intimamente relacionado à evolução das estruturas microscópicas de fluxo nas simulações numéricas.
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References
Barton N, Choubey V (1977) The shear strength of rock joints in theory and practice. Rock Mech 10:1–54. https://doi.org/10.1007/BF01261801
Berkowitz B (2002) Characterizing flow and transport in fractured geological media: a review. Adv Water Resour 25(8):861–884. https://doi.org/10.1016/S0309-1708(02)00042-8
Brown SR, Stockman HW, Reeves SJ (1995) Applicability of the Reynolds equation for modeling fluid flow between rough surfaces. Geophys Res Lett 22(18):2537–2540. https://doi.org/10.1016/0148-9062(96)84991-6
Brush DJ, Thomson NR (2003) Fluid flow in synthetic rough-walled fractures: Navier-Stokes, Stokes, and local cubic law simulations. Water Resour Res 39(4):1085. https://doi.org/10.1029/2002WR001346
Chen YF, Hu SH, Hu R, Zhou CB (2015a) Estimating hydraulic conductivity of fractured rocks from high-pressure packer tests with an Izbash’s law-based empirical model. Water Resour Res 51(4):2096–2118. https://doi.org/10.1002/2014WR016458
Chen YF, Zhou JQ, Hu SH, Hu R, Zhou CB (2015b) Evaluation of Forchheimer equation coefficients for non-Darcy flow in deformable rough-walled fractures. J Hydrol 529:993–1006. https://doi.org/10.1016/j.jhydrol.2015.09.021
Cherubini C, Giasi CI, Pastore N (2012) Bench scale laboratory tests to analyze non-linear flow in fractured media. Hydrol Earth Syst Sci 9(4):5575–5609. https://doi.org/10.5194/hess-16-2511-2012
Forchheimer PH (1901) Water movement through soil (in German). J Assoc Ger Eng 45:1782–1788
Ghane E, Fausey NR, Brown LC (2014) Non-Darcy flow of water through woodchip media. J Hydrol 519:3400–3409
Hu YJ, Mao GH, Cheng WP, Zhang JJ (2005) Theoretical and experimental study on flow distribution at fracture intersections. J Hydraulic Res 43(3):321–327
Iwai K (1976) Fundamental studies of fluid flow through a single fracture. PhD Thesis, California University, Berkeley. https://doi.org/10.1016/0148-9062(79)90543-6
Javadi M, Sharifzadeh M, Shahriar K, Mitani Y (2014) Critical Reynolds number for nonlinear flow through rough-walled fractures: the role of shear processes. Water Resour Res 50(2):1789–1804. https://doi.org/10.1002/2013WR014610
Jing L, Stephansson O (2007) Fundamentals of discrete element methods for rock engineering: theory and applications. Elsevier, Amsterdam, pp 111–138
Johnson J, Brown S, Stockman H (2006) Fluid flow and mixing in rough-walled fracture intersections. J Geophys Res-Solid Earth 111(B12). https://doi.org/10.1029/2005JB004087
Kolditz O (2001) Non-linear flow in fractured rock. Int J Numer Method H 11(6):547–575. https://doi.org/10.1108/EUM0000000005668
Konzuk JS, Kueper BH (2004) Evaluation of cubic law based models describing single-phase flow through a rough-walled fracture. Water Resour Res 40(2):W02402. https://doi.org/10.1029/2003WR002356
Kosakowski G, Berkowitz B (1999) Flow pattern variability in natural fracture intersections. Geophy Res Lett 26(12):1765–1768. https://doi.org/10.1029/1999GL900344
Kumar R, Kumar A, Goel V (2017) Computational fluid dynamics based study for analyzing heat transfer and friction factor in semi-circular rib roughened equilateral triangular duct. Int J Numer Method H 27(4):941–957. https://doi.org/10.1108/hff-10-2015-0438
Li B, Liu RC, Jiang YJ (2016) Influences of hydraulic gradient, surface roughness, intersecting angle, and scale effect on nonlinear flow behavior at single fracture intersections. J Hydrol 538:440–453. https://doi.org/10.1016/j.jhydrol.2016.04.053
Li GM (2002) Tracer mixing at fracture intersections. Environ Geol 42(2–3):137–144. https://doi.org/10.1007/s00254-001-0483-x
Liu J, Wang ZC, Qiao LP, Li W, Yang JJ (2021) Transition from linear to nonlinear flow in single rough fractures: effect of fracture roughness. Hydrogeol J. https://doi.org/10.1007/s10040-020-02297-6
Liu RC, Li B, Jiang YJ (2016a) Critical hydraulic gradient for nonlinear flow through rock fracture networks: the roles of aperture, surface roughness, and number of interactions. Adv Water Resour 88:53–65. https://doi.org/10.1016/j.advwatres.2015.12.002
Liu RC, Li B, Jiang YJ (2016b) A fractal model based on a new governing equation of fluid flow in fractures for characterizing hydraulic properties of rock fracture networks. Comput Geotech 75:57–68. https://doi.org/10.1016/j.compgeo.2016.01.025
Long JCS, Remer JS, Wilson CR, Witherspoon PA (1982) Porous media equivalents for networks of discontinuous fractures. Water Resour Res 18(3):645–658. https://doi.org/10.1029/WR018i003p00645
Moutsopoulos KN, Papaspyros INE, Tsihrintzis VA (2009) Experimental investigation of inertial flow processes in porous media. J Hydrol 374(3):242–254. https://doi.org/10.1016/j.jhydrol.2009.06.015
Mourzenko VV, Thovert JF, Adler PM (1995) Permeability of a single fracture: validity of the Reynolds equation. J Phys II 5(3):465–482. https://doi.org/10.1051/jp2:1995133
Munson BR, Young DF, Okiishi TH (1994) Fundamentals of fluid mechanics. Wiley, New York
National Research Council (1996) Rock fractures and fluid flow: contemporary understanding and applications. National Academy Press, Washington, DC, 65 pp
Park Y, Dreuzy JD, Lee K, Berkowitz B (2001) Transport and intersection mixing in random fracture networks with power law length distributions. Water Resour Res 37(10):2493–2502. https://doi.org/10.1029/2000WR000131
Park Y, Lee KK, Kosakowski G, Berkowitz B (2003) Transport behavior in three-dimensional fracture intersections. Water Resour Res 39(8):472–477. https://doi.org/10.1029/2002WR001801
Peacock DCP, Sanderson DJ, Rotevatn A (2018) Relationships between fractures. Water Resour Res 106:41–53. https://doi.org/10.1016/j.jsg.2017.11.010
Qian JZ, Zhan HB, Chen Z, Ye H (2011) Experimental study of solute transport under non-Darcian flow in a single fracture. J Hydrol 399(3):246–254. https://doi.org/10.1016/j.jhydrol.2011.01.003
Su BY, Zhan ML, Guo XE (1997) Experimental study on fluid flow in crossed fractures (in Chinese). J Hydraul Eng 5:1–6
Tian KM (1986) The hydraulic properties of crossing-flow in an intersected fracture. Acta Geol Sin 2:202–214. https://doi.org/10.1111/j.1365-3091.1986.tb00751.x
Tzelepis V, Moutsopoulos KN, Papaspyros JNE, Tsihrintzis VA (2015) Experimental investigation of flow behavior in smooth and rough artificial fractures. J Hydrol 521(2):108–118. https://doi.org/10.1016/j.jhydrol.2014.11.054
Wang ZC, Li SC, Qiao LP (2015) Design and test aspects of a water curtain system for underground oil storage caverns in China. Tunn Undergr Space Technol 48:20–34. https://doi.org/10.1016/j.tust.2015.01.009
Wang ZC, Li W, Bi LP, Qiao, LP, Liu RC, Liu J (2018a) Estimation of the REV size and equivalent permeability coefficient of fractured rock masses with an emphasis on comparing the radial and unidirectional flow configurations. Rock Mech Rock Eng 51(5):1457–1471. https://doi.org/10.1007/s00603-018-1422-4
Wang ZC, Li W, Qiao LP, Liu J, Yang JJ (2018b) Hydraulic properties of fractured rock mass with correlated fracture length and aperture in both radial and unidirectional flow configurations. Comput Geotech 104:167–184. https://doi.org/10.1016/j.compgeo.2018.08.017
Wilcox DC (1998) Turbulence modeling for CFD, 2nd edn. DCW Industries. https://doi.org/10.1007/3-540-59280-6_150
Wilson CR, Witherspoon PA (1976) Flow interference effects at fracture intersections. Water Resour Res 12(1):102–104. https://doi.org/10.1029/WR012i001p00102
Wu ZJ, Fan LF, Zhao SH (2018) Effects of hydraulic gradient, intersecting angle, aperture, and fracture length on the nonlinearity of fluid flow in smooth intersecting fractures: an experimental investigation. Geofluids 2018:1–14. https://doi.org/10.1155/2018/9352608
Xiong F, Wei W, Xu C, Jiang Q (2020) Experimental and numerical investigation on nonlinear flow behaviour through three dimensional fracture intersections and fracture networks. Comput Geotech 121:103446. https://doi.org/10.1016/j.compgeo.2020.103446
Zeng Z, Grigg R (2006) A criterion for non-Darcy flow in porous media. Transp Porous Media 63(1):57–59. https://doi.org/10.1007/s11242-005-2720-3
Zhang Z, Nemcik J (2013a) Fluid flow regimes and nonlinear flow characteristics in deformable rock fractures. J Hydrol 477(1):139–151. https://doi.org/10.1016/j.jhydrol.2012.11.024
Zhang Z, Nemcik J (2013b) Friction factor of water flow through rough rock fractures. Rock Mech Rock Eng 46(5):1125–1134. https://doi.org/10.1007/s00603-012-0328-9
Zhou JQ, Hu SH, Chen YF, Wang M, Zhou CB (2016) The friction factor in the Forchheimer equation for rock fractures. Rock Mech Rock Eng 49(8):3055–3068. https://doi.org/10.1007/s00603-016-0960-x
Zhu HG, Yi C, Jiang YD, Xie HP, Yang MZ (2015) Effect of fractures cross connection on fluid flow characteristics of mining-induced rock (in Chinese). J China Univ Min Technol 44(1):24–28. https://doi.org/10.13247/j.cnki.jcumt.000283
Zimmerman RW, Bodvarsson GS (1996) Hydraulic conductivity of rock fractures. Transp Porous Media 23(1):1–30. https://doi.org/10.1007/bf00145263
Zimmerman RW, Al-Yaarubi A, Pain CC, Grattoni CA (2004) Nonlinear regimes of fluid flow in rock fractures. Int J Rock Mech Min Sci 41(3):163–169. https://doi.org/10.1016/j.ijrmms.2004.03.036
Zou L, Jing L, Cvetkovic V (2015) Roughness decomposition and nonlinear fluid flow in a single fracture. Int J Rock Mech Min Sci 75:102–118. https://doi.org/10.1016/j.ijrmms.2015.01.016
Funding
This study was financially supported by the National Natural Science Foundation of China under contract Nos. 51779045, 51579141 and 42177157, the Fundamental Research Funds for the Central Universities under contract Nos. N180104022, N2001026 and N2101020, Liao Ning Revitalization Talents Program under contract No. XLYC1807029 and Liaoning Natural Science Foundation under contract No. 2019-YQ-02.
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Appendix: Nomenclature
Appendix: Nomenclature
- A :
-
Linear coefficient
- B :
-
Nonlinear coefficient
- C :
-
Constant
- e :
-
Aperture of fracture
- E :
-
Non-Darcy effect factor
- JRC:
-
Joint roughness coefficient
- k :
-
Turbulent kinetic energy
- l :
-
Length of fracture
- P :
-
Fluid pressure
- ∆Pi:
-
Pressure drop
- Q :
-
Volume flow rate
- Re:
-
Reynolds number
- Rr:
-
Influence scale of intersection
- v, U:
-
Flow velocity
- w :
-
Width of fracture
Greek symbols
- β :
-
Non-Darcy coefficient
- ε :
-
Turbulence dissipation rate
- θ :
-
Angle between branches or intersecting angle
- μ :
-
Dynamic viscosity of fluids
- ρ :
-
Fluid density
- σ :
-
Prandtl number
- τ :
-
Reynolds stress tensor
Subscripts
- c:
-
Critical
- i, j :
-
Number of branches
- m, n:
-
Number of rows and columns of matrix
- t :
-
Branch number of the square term of \( {Q}_t^2 \)
- T:
-
Turbulence
- ε :
-
Turbulence dissipation rate
- μ :
-
Dynamic viscosity
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Wang, Z., Liu, J., Qiao, L. et al. A model for nonlinear flow behavior in two-dimensional fracture intersections and the estimation of flow model coefficients. Hydrogeol J 30, 865–879 (2022). https://doi.org/10.1007/s10040-022-02453-0
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DOI: https://doi.org/10.1007/s10040-022-02453-0