INL Science Focus Area Project

RE3: Model Application, Validation and Development

 

Lead: Hai Huang (INL)

Participants: Luanjing Guo (INL), Zhijie Xu (currently at PNNL), Alexandre Tartakovsky (PNNL)

Computer simulations are mainly used to test our understanding of the complex interactions occurring at various scales – from pore to continuum – between fluid flow, transport, reactions, and changes in media properties in porous media that will be investigated in the RE1 experiments. Pre-experimental simulations are also extremely valuable for developing testable hypotheses and constructing experiments.

 

Pore-scale Modeling

1. Simulations at pore-scale are conducted to study the interaction between mineral precipitation and changes in porosity/permeability. Both phase field and level set methods have been used.

1) Phase field

Figure Precipitation initiated from a solid seed with far-field concentration 0.5 (left), and precipitation in solid pipe with a fixed center concentration 0.5 showing the clogging effect (right); red - reactive fluid phase, blue - solid phase.

 

2) Level set

  Figure Upscaling results of relationship between permeability and porosity from pore-scale reactive flow simultaions with corresponding fracture and/or porous medium geometries for arious flow and reaction regimes. Black - diffusion dominated and slow reaction; blue - advection dominated and fast reaction; red - diffusion dominated and fast reaction.

 

 

Continuum-scale Modeling

1. Codes available

TOUGHREACT (multi-phase reactive transport simulator, LBNL) and STOMP (Subsurface Transport Over Multiple Phases, PNNL) have initially been adopted and applied to SFA program. They have been applied to conducting preliminary studies on parallel injection experiment, and on in situ reactant generation experiments (see Program Overview page). Selected Results are shown below.

  

Figure TOUGREACT simulation of calcite precipitation by parallel injection of reactant solutions.

 

Figure Conceptual model of urea injection into a physically and chemically heterogeneous porous media; and STOMP simulation results of flow paths and temporal and spatial distributions of calcite precipitation.

 

2. Code developed

RAT (ReActive Transport) simulator has been developed as part of the modeling effort of INL SFA project. It has several advantages over the conventional simulators: 1) massive parallelism and scalability; 2) fully-coupled solution approach (JFNK) suitable to the engineering systems that our SFA is focused on; and 3) adaptive mesh refinement. The simulator has been applied to investigate the in situ production experiment campaign. Selected results are shown below.

Figure Simulations of the distribution of calcium carbonate precipitates along the column. The color shows the increase in the amount, and the solid lines show the temporal distribution of precipitates.

Figure The comparison between RAT simulations and experimental measurements of the species concentration profiles for the column test of ureolytical calcium carbonate precipitation. Black line - simulation results, red dots - experimental data.

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