Modeling CO2 Storage in Aquifers with a Fully-Coupled Geochemical EOS Compositional Simulator

2004 ◽  
Author(s):  
Long Nghiem ◽  
Peter Sammon ◽  
Jim Grabenstetter ◽  
Hiroshi Ohkuma
Keyword(s):  
Co2 Storage ◽  
Compositional Simulator ◽  
Fully Coupled

scholarly journals A coupling alternative to reactive transport simulations for long-term prediction of chemical reactions in heterogeneous CO<sub>2</sub> storage systems

2014 ◽  
Vol 7 (5) ◽  
pp. 6217-6261 ◽  
Author(s):  
M. De Lucia ◽  
T. Kempka ◽  
M. Kühn
Keyword(s):  
Chemical Reactions ◽  
Exposure Time ◽  
Reactive Transport ◽  
Storage Systems ◽  
Co2 Storage ◽  
Threshold Value ◽  
Co2 Injection ◽  
Coupled Models ◽  
Minimum Concentration ◽  
Fully Coupled

Abstract. Fully-coupled, multi-phase reactive transport simulations of CO2 storage systems can be approximated by a simplified one-way coupling of hydrodynamics and reactive chemistry. The main characteristics of such systems, and hypotheses underlying the proposed alternative coupling, are (i) that the presence of CO2 is the only driving force for chemical reactions and (ii) that its migration in the reservoir is only marginally affected by immobilization due to chemical reactions. In the simplified coupling, the exposure time to CO2 of each element of the hydrodynamic grid is estimated by non-reactive simulations and the reaction path of one single batch geochemical model is applied to each grid element during its exposure time. In heterogeneous settings, analytical scaling relationships provide the dependency of velocity and amount of reactions to porosity and gas saturation. The analysis of TOUGHREACT fully coupled reactive transport simulations of CO2 injection in saline aquifer, inspired to the Ketzin pilot site (Germany), both in homogeneous and heterogeneous settings, confirms that the reaction paths predicted by fully coupled simulations in every element of the grid show a high degree of self-similarity. A threshold value for the minimum concentration of dissolved CO2 considered chemically active is showed to mitigate the effects of the discrepancy between dissolved CO2 migration in non-reactive and fully coupled simulations. In real life, the optimal threshold value is unknown and has to be estimated, e.g., by means of 1-D or 2-D simulations, resulting in an uncertainty ultimately due to the process de-coupling. However, such uncertainty is more than acceptable given that the alternative coupling enables using grids in the order of million elements, profiting from much better description of heterogeneous reservoirs at a fraction of the calculation time of fully coupled models.

scholarly journals A coupling alternative to reactive transport simulations for long-term prediction of chemical reactions in heterogeneous CO<sub>2</sub> storage systems

2015 ◽  
Vol 8 (2) ◽  
pp. 279-294 ◽  
Author(s):  
M. De Lucia ◽  
T. Kempka ◽  
M. Kühn
Keyword(s):  
Chemical Reactions ◽  
Exposure Time ◽  
Reactive Transport ◽  
Storage Systems ◽  
Co2 Storage ◽  
Threshold Value ◽  
Co2 Injection ◽  
Coupled Models ◽  
Minimum Concentration ◽  
Fully Coupled

Abstract. Fully coupled, multi-phase reactive transport simulations of CO2 storage systems can be approximated by a simplified one-way coupling of hydrodynamics and reactive chemistry. The main characteristics of such systems, and hypotheses underlying the proposed alternative coupling, are (i) that the presence of CO2 is the only driving force for chemical reactions and (ii) that its migration in the reservoir is only marginally affected by immobilisation due to chemical reactions. In the simplified coupling, the exposure time to CO2 of each element of the hydrodynamic grid is estimated by non-reactive simulations and the reaction path of one single batch geochemical model is applied to each grid element during its exposure time. In heterogeneous settings, analytical scaling relationships provide the dependency of velocity and amount of reactions to porosity and gas saturation. The analysis of TOUGHREACT fully coupled reactive transport simulations of CO2 injection in saline aquifer, inspired to the Ketzin pilot site (Germany), both in homogeneous and heterogeneous settings, confirms that the reaction paths predicted by fully coupled simulations in every element of the grid show a high degree of self-similarity. A threshold value for the minimum concentration of dissolved CO2 considered chemically active is shown to mitigate the effects of the discrepancy between dissolved CO2 migration in non-reactive and fully coupled simulations. In real life, the optimal threshold value is unknown and has to be estimated, e.g. by means of 1-D or 2-D simulations, resulting in an uncertainty ultimately due to the process de-coupling. However, such uncertainty is more than acceptable given that the alternative coupling enables using grids of the order of millions of elements, profiting from much better description of heterogeneous reservoirs at a fraction of the calculation time of fully coupled models.

A Fully Coupled Multiphase Multicomponent Flow and Geomechanics Model for Enhanced Coalbed-Methane Recovery and CO2 Storage

SPE Journal ◽  
2013 ◽  
Vol 18 (03) ◽  
pp. 448-467 ◽  
Author(s):  
Zhijie Wei ◽  
Dongxiao Zhang
Keyword(s):  
Fluid Flow ◽  
Coalbed Methane ◽  
Co2 Storage ◽  
Stress Effect ◽  
Multicomponent Flow ◽  
Coupling Effects ◽  
Multicomponent Gas ◽  
Enhanced Coalbed Methane ◽  
The Impact ◽  
Fully Coupled

Summary Enhanced coalbed-methane (ECBM) recovery by the injection of CO2 and/or N2 is an attractive method for recovering additional natural gas resources, while at the same time sequestering CO2 in the subsurface. For the naturally fractured coalbed-methane (CBM) reservoirs, the coupled fluid-flow and geomechanics effects involving both the effective-stress effect and the matrix shrinkage/swelling, are crucial to simulate the permeability change and; thus gas migration during primary or enhanced CBM recovery. In this work, a fully coupled multiphase multicomponent flow and geomechanics model is developed. The coupling effects are modeled by introducing a set of elaborate geomechanical equations, which can provide more fundamental understanding about the solid deformation and give a more accurate permeability/porosity prediction over the existing analytical models. In addition, the fluid-flow model in our study is fully compositional; considering both multicomponent gas dissolution and water volatility. To obtain accurate gas solubility in the aqueous phase, the Peng-Robinson equation of state (EOS) is modified according to the suggestions of Søreide and Whitson (1992). An extended Langmuir isotherm is used to describe the adsorption/desorption behavior of the multicomponent gas to/from the coal surface. With a fully implicit finite-difference method, we develop: a 3D, multiphase, multicomponent, dual-porosity CBM/ECBM research code that is fully compositional and has fully coupled fluid flow and geomechanics. It has been partially validated and verified by comparison against other simulators such as GEM, Eclipse, and Coalgas. We then perform a series of simulations/investigations with our research code. First, history matching of Alberta flue-gas-injection micropilot data is performed to test the permeability model. The commonly used uniaxial-strain and constant-overburden-stress assumptions for analytical permeability models are then assessed. Finally, the coupling effects of fluid flow and geomechanics are investigated, and the impact of different mixed CO2/N2 injection scenarios is explored for both methane (CH4) production and CO2 sequestration.

Simulation of CO2 storage in a heterogeneous aquifer

2009 ◽  
Vol 223 (3) ◽  
pp. 249-267 ◽  
Author(s):  
C Ukaegbu ◽  
O Gundogan ◽  
E Mackay ◽  
G Pickup ◽  
A Todd ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Computer Modelling ◽  
Co2 Storage ◽  
Flow Simulation ◽  
Geological Structure ◽  
Gas Diffusion ◽  
Lateral Migration ◽  
Deep Saline Aquifer ◽  
System A ◽  
Compositional Simulator

The fate of carbon dioxide (CO2) injected into a deep saline aquifer depends largely on the geological structure within the aquifer. For example, low permeability layers, such as shales or mudstones, will act as barriers to vertical flow of CO2 gas, whereas high permeability channels may assist the lateral migration of CO2. It is therefore important to include permeability heterogeneity in models for numerical flow simulation As an example of a heterogeneous system, a model of fluvial-incised valley deposits was used. Flow simulations were performed using the generalized equation-of-state model—greenhouse gas software package from Computer Modelling Group, which is a compositional simulator, specially adapted for CO2 storage. The impacts of residual gas and water saturations, gas diffusion in the aqueous phase, hysteresis, and permeability anisotropy on the distribution of CO2 between the gaseous and aqueous phases were examined. Gas diffusion in the aqueous phase was found to significantly enhance solubility trapping of CO2, even when hysteretic trapping of CO2 as a residual phase is taken into account.

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