TOGA: A TOUGH code for modeling three-phase, multi-component, and non-isothermal processes involved in CO2-based Enhanced Oil Recovery
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
TOGA is a numerical reservoir simulator for modeling non-isothermal flow and transport of water, CO2, multicomponent oil, and related gas components for applications including CO2-enhanced oil recovery (CO2-EOR) and geologic carbon sequestration in depleted oil and gas reservoirs. TOGA uses an approach based on the Peng-Robinson equation of state (PR-EOS) to calculate the thermophysical properties of the gas and oil phases including the gas/oil components dissolved in the aqueous phase, and uses a mixing model to estimate the thermophysical properties of the aqueous phase. The phase behavior (e.g., occurrence and disappearance of the three phases, gas + oil + aqueous) and the partitioning of non-aqueous components (e.g., CO2, CH4, and n-oil components) between coexisting phases are modeled using K-values derived from assumptions of equal-fugacity that have been demonstrated to be very accurate as shown by comparison to measured data. Models for saturated (water) vapor pressure and water solubility (in the oil phase) are used to calculate the partitioning of the water (H2O) component between the gas and oil phases. All components (e.g., CO2, H2O, and n hydrocarbon components) are allowed to be present in all phases (aqueous, gaseous, and oil). TOGA uses a multiphase version of Darcy’s Law to model flow and transport through porous media of mixtures with up to three phases over a range of pressures and temperatures appropriate to hydrocarbon recovery and geologic carbon sequestration systems. Transport of the gaseous and dissolved components is by advection and Fickian molecular diffusion. New methods for phase partitioning and thermophysical property modeling in TOGA have been validated against experimental data published in the literature for describing phase partitioning and phase behavior. Flow and transport has been verified by testing against related TOUGH2 EOS modules and CMG. The code has also been validated against a CO2-EOR experimental core flood involving flow of three phases and 12 components. Results of simulations of a hypothetical 3D CO2-EOR problem involving three phases and multiple components are presented to demonstrate the field-scale capabilities of the new code. This user guide provides instructions for use and sample problems for verification and demonstration.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 1332134
- Report Number(s):
- LBNL--1006472; ir:1006472
- Country of Publication:
- United States
- Language:
- English
Similar Records
Development and Application of Preliminary TOGA Model for CO2-EOR with Comparison to Resistivity Data
Retardation of dissolved oxygen due to a trapped gas phase in porous media