TOUGH2 - The Forward Model

The Forward Model: TOUGH2

iTOUGH2 relies on the TOUGH2 code for the solution of the forward problem. TOUGH2 is a general-purpose numerical simulator for multiphase fluid and heat flow in fractured-porous media, with applications in geothermal reservoir engineering, nuclear waste disposal, and environmental contamination problems.

Visit the TOUGH2 Web Site for a detailed description of the program.

The TOUGH2 family of codes consists of a number of fluid property and process modules. A list of available modules as well as recent code developments are maintained on the TOUGH2 web site. The core of iTOUGH2 contains slightly modified versions of some of the TOUGH2 modules (see table below). Furthermore, some features have been added to all modules (printout control, secondary mesh, element-by-element properties, user-specified boundary conditions, new relative permeability and capillary pressure functions.) These modifications are described in the iTOUGH2 Command Reference.

The following table summarizes the TOUGH2 modules that are currently adapted for use with iTOUGH2.

TOUGH2 Modules available in iTOUGH2
Module Capability
T2CG1 Preconditioned conjugate gradient solvers.
EOS1 Fluid property module for non-isothermal two-phase flow of water and water with tracer.
EOS2 Fluid property module for non-isothermal two-phase flow of water and CO₂.
EOS3 Fluid property module for non-isothermal two-phase flow of water and air.
EOS3ECM Fluid property module for non-isothermal two-phase flow of water and air, with ECM formulation for fracture-matrix interaction.
EOS3NN Fluid property module for non-Newtonian two-phase flow of water and air.
EOS4 Fluid property module for non-isothermal two-phase flow of water and air, with vapor pressure lowering.
EOS5 Fluid property module for non-isothermal two-phase flow of water and hydrogen.
EOS7 Fluid property module for non-isothermal two-phase flow of water, brine, and air.
EOS7R Fluid property module for non-isothermal two-phase flow of water, brine, parent radionuclide, daughter radionuclide, and air.
EOS8 Fluid property module for non-isothermal three-phase flow of water, non-condensible gas, and black oil.
EOS9 Fluid property module for saturated/unsaturated flow according to Richards' equation (gas phase as passive bystander).
EOS9ECM Fluid property module for saturated/unsaturated flow according to Richards' equation (gas phase as passive bystander), with ECM formulation for fracture-matrix interaction.
EOS9nT Fluid property module for saturated/unsaturated flow and solute/colloid transport.
EOS10 (T2VOC) A module for non-isothermal three-phase (aqueous, gas, NAPL), three-component flow of water, air and a volatile organic compound (VOC).
EOS11 Fluid property module for non-isothermal two-phase flow of water, air, and a miscible gelling liquid
EOS13 Fluid property module for non-isothermal two-phase flow of water and methane.
EOS12 Fluid property module for non-isothermal two-phase flow of water and methane.
EOS14 (EWASG) Fluid property module for non-isothermal two-phase flow of water, water-soluble salt, and non-condensible gas; includes salt dissolution and precipitation and associated porosity and permeability changes, and vapor pressure lowering.
T2HYST Hysteretic capillary pressure and relative permeability relationships for all two-phase modules.
IFS Characterization of heterogeneity using Iterated Function Systems.

TOUGH2 Modules available in iTOUGH2
Module	Capability
T2CG1	Preconditioned conjugate gradient solvers.
EOS1	Fluid property module for non-isothermal two-phase flow of water and water with tracer.
EOS2	Fluid property module for non-isothermal two-phase flow of water and CO₂.
EOS3	Fluid property module for non-isothermal two-phase flow of water and air.
EOS3ECM	Fluid property module for non-isothermal two-phase flow of water and air, with ECM formulation for fracture-matrix interaction.
EOS3NN	Fluid property module for non-Newtonian two-phase flow of water and air.
EOS4	Fluid property module for non-isothermal two-phase flow of water and air, with vapor pressure lowering.
EOS5	Fluid property module for non-isothermal two-phase flow of water and hydrogen.
EOS7	Fluid property module for non-isothermal two-phase flow of water, brine, and air.
EOS7R	Fluid property module for non-isothermal two-phase flow of water, brine, parent radionuclide, daughter radionuclide, and air.
EOS8	Fluid property module for non-isothermal three-phase flow of water, non-condensible gas, and black oil.
EOS9	Fluid property module for saturated/unsaturated flow according to Richards' equation (gas phase as passive bystander).
EOS9ECM	Fluid property module for saturated/unsaturated flow according to Richards' equation (gas phase as passive bystander), with ECM formulation for fracture-matrix interaction.
EOS9nT	Fluid property module for saturated/unsaturated flow and solute/colloid transport.
EOS10 (T2VOC)	A module for non-isothermal three-phase (aqueous, gas, NAPL), three-component flow of water, air and a volatile organic compound (VOC).
EOS11	Fluid property module for non-isothermal two-phase flow of water, air, and a miscible gelling liquid
EOS13	Fluid property module for non-isothermal two-phase flow of water and methane.
EOS12	Fluid property module for non-isothermal two-phase flow of water and methane.
EOS14 (EWASG)	Fluid property module for non-isothermal two-phase flow of water, water-soluble salt, and non-condensible gas; includes salt dissolution and precipitation and associated porosity and permeability changes, and vapor pressure lowering.
T2HYST	Hysteretic capillary pressure and relative permeability relationships for all two-phase modules.
IFS	Characterization of heterogeneity using Iterated Function Systems.

Page updated: December 9, 2002