Flujo agua-gas en fracturas de rocas rugosas: conocimientos a partir de experimentos de compresión triaxial acoplada

Translated title of the contribution: Water-gas flow in rough rock fractures: insights from coupled triaxial compression experiments

Yakun Wang, Zhenyu Zhang, Pathegama Gamage Ranjith, Yong Luo

Research output: Contribution to journalArticleResearchpeer-review

8 Citations (Scopus)

Abstract

To investigate two-phase fluid flow processes influenced by phase interference, pressure drop, fracture roughness and environmental stress, a nitrogen-water two-phase flow experiment was carried out on highly rough granite fractures in an experimental triaxial cell. Pressure was used to control the two-phase fluid in the fracture. The results show that each fluid phase has a separate flow channel, even through rock fractures of large roughness. Correlation of the superficial velocities of the two-phase fluids identifies the annular flow at a high pressure drop due to the high kinetic energy of the gas phase; however, annular flow transitioned to complex flow with increasing fracture roughness and confining pressure. The relative permeability of water is greater than that of gas. The sum of the relative permeabilities of the two phases is less than unity due to phase interference. With increasing pressure head, confining pressure, and fracture roughness, the relative permeability of water shows a general decreasing trend and the sum of relative permeability continuously reduced, demonstrating that the localized flow paths of the different phases changed and the phase interference increased. The experimental relative permeability of gas is greater here than that determined by the nonlinear viscous coupling model and Corey model, but less than the straight-line relative permeability model (X-model). Among them, the viscous coupling model provides the closest approximation, indicating that the physical process of two-phase flow through highly rough and tight rock fractures is more like that through a pipe, rather than through porous media and parallel-plate channels.

Translated title of the contributionWater-gas flow in rough rock fractures: insights from coupled triaxial compression experiments
Original languageSpanish
Pages (from-to)1569-1581
Number of pages13
JournalHydrogeology Journal
Volume30
Issue number5
DOIs
Publication statusPublished - Aug 2022

Keywords

  • Flow structure transition
  • Fractured rocks
  • Laboratory experiments
  • Multiphase flow
  • Relative permeability

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