| Geomechanics and Engineering Volume 13, Number 1, July 2017, pages 1-23 DOI: https://doi.org/10.12989/gae.2017.13.1.001 | |
Modeling of coupled liquid-gas-solid three-phase processes due to fluid injection
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Yong-Ge Zang, Dong-Mei Sun, Ping Feng and Semprich Stephan
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| Abstract [Buy Article] | |
| A coupled liquid-gas-solid three-phase model, linking two numerical codes (TOUGH2/EOS3 and FLAC3D), was firstly established and validated by simulating an in-situ air flow test in Essen. Then the coupled model was employed to investigate responses of multiphase flow and soil skeleton deformation to compressed air or freshwater injection using the same simulation conditions in an aquifer of Tianjin, China. The simulation results show that with injecting pressurized fluids, the vertical effective stress in some area decreases owing to the pore pressure increasing, an expansion of soil skeleton appears, and land uplift occurs due to support actions from lower deformed soils. After fluids injection stops, soil deformation decreases overall due to injecting fluids dissipating. With the same applied pressure, changes in multiphase flow and geo-mechanical deformation caused by compressed air injection are relatively greater than those by freshwater injection. Furthermore, the expansion of soil skeleton induced by compressed air injection transfers upward and laterally continuously with time, while during and after freshwater injection, this expansion reaches rapidly a quasi-steady state. These differences induced by two fluids injection are mainly because air could spread upward and laterally easily for its lower density and phase state transition appears for compressed air injection. | |
| Key Words | |
| coupled liquid-gas-solid three-phase model; compressed air injection; freshwater injection; geo-mechanical analysis; effective stress | |
| Address | |
| (1) Yong-Ge Zang, Dong-Mei Sun, Ping Feng: State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300072, China; (2) Semprich Stephan: Institute of Soil Mechanics and Foundation Engineering, Graz University of Technology, 8010 Graz, Austria. | |
