Transport in Porous Media

, Volume 96, Issue 1, pp 173–192 | Cite as

Simulation of Dynamic Two-Phase Flow During Multistep Air Sparging

Open Access
Article

Abstract

Air sparging is an in situ soil/groundwater remediation technology, which involves the injection of pressurized air through air sparging well below the zone of contamination. To investigate the rate-dependent flow properties during multistep air sparging, a rule-based dynamic two-phase flow model was developed and applied to a 3D pore network which is employed to characterize the void structure of porous media. The simulated dynamic two-phase flow at the pore scale or microscale was translated into functional relationships at the continuum-scale of capillary pressure–saturation (P cS) and relative permeability—saturation (K rS) relationships. A significant contribution from the air injection pressure step and duration time of each air injection pressure on both of the above relationships was observed during the multistep air sparging tests. It is observed from the simulation that at a given matric potential, larger amount of water is retained during transient flow than that during steady flow. Shorter the duration of each air injection pressure step, there is higher fraction of retained water. The relative air/water permeability values are also greatly affected by the pressure step. With large air injection pressure step, the air/water relative permeability is much higher than that with a smaller air injection pressure step at the same water saturation level. However, the impact of pressure step on relative permeability is not consistent for flows with different capillary numbers (N ca). When compared with relative air permeability, relative water permeability has a higher scatter. It was further observed that the dynamic effects on the relative permeability curve are more apparent for networks with larger pore sizes than that with smaller pore sizes. In addition, the effect of pore size on relative water permeability is higher than that on relative air permeability.

Keywords

Pore network model Dynamic two-phase flow Air sparging Capillary pressure–saturation Relative permeability–saturation 

Notes

Acknowledgments

The authors would like to acknowledge the financial support from State Key Laboratory of Hydro Science and Engineering (SKLHSE-2010-D1, SKLHSE-2012-KY-01), National Key Basic Research Program (2012CB719804), Beijing Scientific Research Program (D07050601510000), and National Natural Science Foundation of China (Project No. 50879038).

Open Access

This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.

References

  1. Arns Y.J., Robins V., Sheppard A.P., Sok R.M, Pinczewski W.V., Knackstedt M.A.: Effect of network topology on relative permeability. Transp. Porous Media 55(1), 21–46 (2004)CrossRefGoogle Scholar
  2. Bausmith D.S., Campbell D.J., Vidic R.D.: In situ air stripping. Water Environ. Technol. 8(2), 45–51 (1996)Google Scholar
  3. Blunt M.J., Jackson M.D., Piri M., Valvatne P.H.: Detailed physics, predictive capabilities and macroscopic consequences for network models of multiphase flow. Adv. Water Res. 25(8–12), 1069–1089 (2002)CrossRefGoogle Scholar
  4. Chandler R., Koplick J., Lerman K., Willemsen J.F.: Capillary displacement and percolation in porous media. J. Fluid. Mech. 119, 249–267 (1982)CrossRefGoogle Scholar
  5. Chen J.D., Wilkinson D.: Pore-scale viscous fingering in porous media. Phys. Rev. Lett. 55, 1892–1895 (1985)CrossRefGoogle Scholar
  6. Davidson J.M., Nielsen D.R., Biggar J.W.: The dependence of soil water uptake and release upon the applied pressure increment. Soil Sci. Soc. Am. Proc. 30, 298–304 (1966)CrossRefGoogle Scholar
  7. Gao, S., Meegoda, J.N., Hu, L.: Two methods for pore network of porous media. Int. J. Numer. Anal. Methods Geomech. (2011). http://dx.doi.org/10.1002/nag.1134
  8. Hu L., Wu X., Liu Y., Meegoda J., Gao S.: Physical modeling of air flow during air sparging remediation. Environ. Sci. Technol. 44(10), 3883–3888 (2010)CrossRefGoogle Scholar
  9. Hu L., Meegoda J., Du J., Gao S., Wu X.: Centrifugal study of zone of influence during air-sparging. J. Environ. Monit. 13(9), 2443–2449 (2011)CrossRefGoogle Scholar
  10. Jerauld G.R., Salter S.J.: The effect of pore-structure on hysteresis in relative permeability and capillary pressure: pore-level modeling. Transp. Porous Media 5, 103–151 (1990)CrossRefGoogle Scholar
  11. Lenormand R., Zarcone C.: Invasion percolation in an etched network: measurement of a fractal dimension. Phys. Rev. Lett. 54, 2226–2229 (1984)CrossRefGoogle Scholar
  12. Leonard, W.C., Brown, R.A.: Air sparging: an optimal solution. In: Proceedings of Petroleum Hydrocarbons and Organic Chemicals in Groundwater: Prevention, Detection and Restoration, Houston, Texas, 349–363, 4–6 Nov, 1992Google Scholar
  13. Meakin P.: Diffusion-controlled cluster formation in 2–6-dimensional space. Phys. Rev. A 27(3), 1495–1507 (1983a)CrossRefGoogle Scholar
  14. Meakin P.: Diffusion-controlled deposition on fibers and surfaces. Phys. Rev. A 27(5), 2616–2623 (1983b)CrossRefGoogle Scholar
  15. Meakin P., Stanley H.E.: Novel dimension-independent behavior for diffusive annihilation on percolation fractals. J. Phys. A Math. Gen. 17, 1173–1177 (1984)CrossRefGoogle Scholar
  16. Mohanty, K.K, Salter, S.J.: Multiphase flow in porous media. Part 2. Pore-level modeling. In: 57th AIME Society of Petroleum Engineers annual technical conference and exhibition, New Orleans, LA, USA, Sept 26, SPE-11018 (1982)Google Scholar
  17. Singh M., Mohanty K.K.: Dynamic modeling of drainage through three-dimensional porous materials. Chem. Eng. Sci. 58, 1–18 (2003)CrossRefGoogle Scholar
  18. Smiles D.E., Vachaud G., Vauclin M.: A test of the uniqueness of the soil moisture characteristic during transient, non-hysteretic flow of water in a rigid soil. Soil Sci. Soc. Am. Proc. 35, 535–539 (1971)CrossRefGoogle Scholar
  19. Topp G.C., Klute A., Peters D.B.: Comparison of water content-pressure head data obtained by equilibrium, steady-state, and unsteady-state methods. Soil Sci. Soc. Am. Proc. 31, 312–314 (1967)CrossRefGoogle Scholar
  20. Vachaud G., Vauclin M., Wakil M.: A study of the uniqueness of the soil moisture characteristic during desorption by vertical drainage. Soil Sci. Soc. Am. Proc. 36, 531–532 (1972)CrossRefGoogle Scholar
  21. Wilkinson D., Willemsen J.F.: Invasion percolation: a new form of percolation theory. J. Phys. A Math. Gen. 16(14), 3365–3376 (1983)CrossRefGoogle Scholar
  22. Witten T.A., Sander L.M.: Diffusion-limited aggregation. Phys. Rev. B 27(9), 5686–5697 (1983)CrossRefGoogle Scholar

Copyright information

© The Author(s) 2012

Authors and Affiliations

  1. 1.Department of Hydraulic Engineering, State Key Laboratory of Hydro-Science and EngineeringTsinghua UniversityBeijingPeople’s Republic of China
  2. 2.Department of Civil and Environmental EngineeringNew Jersey Institute of TechnologyNewarkUSA

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