Title: On the dynamics and kinematics of two-fluid-phase flow in porous media

Abstract

A model formulated in terms of both conservation and kinematic equations for phases and interfaces in two-fluid-phase flow in a porous medium system is summarized. Macroscale kinematic equations are derived as extensions of averaging theorems and do not rely on conservation principles. Models based on both conservation and kinematic equations can describe multiphase flow with varying fidelity.When only phase-based equations are considered, a model similar in form to the traditional model for two-fluid-phase flow results. When interface conservation and kinematic equations are also included, a novel formulation results that naturally includes evolution equations that express dynamic changes in fluid saturations, pressures, the capillary pressure, and the fluid-fluid interfacial area density in a two-fluid-system. This dynamic equation set is unique to this work, and the importance of the modeled physics is shown through both microfluidic experiments and high-resolution lattice Boltzmann simulations. The validation work shows that the relaxation of interface distribution and shape toward an equilibrium state is a slow process relativeto the time scale typically allowed for a system to approach an apparent equilibrium state based upon observations of fluid saturations and external pressure measurements. Consequently, most pressure-saturation data intended to denote an equilibrium state are likely a sampling frommore » a dynamic system under-going changes of interfacial curvatures that are not typically monitored. The results confirm the importance of kinematic analysis in combination with conservation equations for faithful modeling of system physics.« less

Authors:

Gray, W. G. ^[1]; Dye, A. L. ^[1]; McClure, J. E. ^[2]; Pyrak-Nolte, L. J. ^[3]; Miller, C. T. ^[1]

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+ Show Author Affiliations

1. Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Environmental Sciences and Engineering
2. Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States). Advanced Research Computing
3. Purdue Univ., West Lafayette, IN (United States). Dept. of Physics and Astronomy, Dept. of Earth, Atmospheric and Planetary Science, and Lyles School of Civil Engineering

Publication Date:

Tue Jun 16 00:00:00 EDT 2015

Research Org.:

Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); University of North Carolina, Chapel Hill, NC (United States)

Sponsoring Org.:

USDOE Office of Science (SC); National Science Foundation (NSF); US Army Research Office (ARO)

OSTI Identifier:

1565263

Grant/Contract Number:  

SC0002163; W911NF‐14‐1‐0287; 0941235; 1314663‐EAR

Resource Type:

Accepted Manuscript

Journal Name:

Water Resources Research

Additional Journal Information:

Journal Volume: 51; Journal Issue: 7; Journal ID: ISSN 0043-1397

Publisher:

American Geophysical Union (AGU)

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources; multiphase flow; porous media; lattice Boltzmann; micromodels; kinematics