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| Titel |
CO2-Storage Simulation with regard to Cold Hydro-Fracturing and Vaporization/Condensation |
| VerfasserIn |
Mohammed Amro, Frieder Häfner |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250047538
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| Zusammenfassung |
| The simulation of the process of CO2 storage in porous media requires the solution of the coupled system of differential equations of multiphase flow, transport of CO2 in liquid and gaseous (supercritical) conditions and other gases, transport of dissolved CO2 in water and transport of energy (temperature). Therefore, the implementation of the thermodynamic phase behaviour of CO2 in all possible options is necessary. Moreover, the chemical reactions between CO2 and rock material should be considered.
The main aim of developing inhouse simulation software Mod2Phase was to include the enthalpy behaviour, and pressure- and temperature dependent phase behaviour during the injection of cold liquid CO2 in deep and high temperature formations. With the new simulation software Mod2Phase-thermo the stimulation of low permeable and deep formations of Pre-Zechstein can be simulated, which will consider the high pressure – low-temperature effects during CO2 (liquid) injection. The required temperature reduction is expected to be about 100 K.
All differential equations will be solved numerically using balance method in 3D-cartesian coordinate system. The flow- and transport-equations might be solved individually or if necessary by iteration. The required time step control is based on physical background (3D-Courant-condition) referred to Picard-Iteration and is depending on the solvability of the equation system using Newton-Raphson-Iteration.
All relevant thermodynamic data of CO2 and water involved are integrated in the software. In relation to pressure and temperature the phase change of CO2 from liquid to gas, and from liquid to supercritical, respectively will be considered in capillary effects, change of saturation, concentration and temperature (evaporation-enthalpy).
The software has the option at a given time to access the geochemical software PhreeqC. An iteration of geochemistry and transport is not necessary due to different time-scales.
For the validation of the software Benchmark-Tests [Class et al., 2009] were simulated. The obtained results showed a good match with the published results. The software Mod2Phase was implemented in a study for a Pre-Zechstein CO2-Storage and for fundamental investigations of cold-hydro-fracturing with liquid CO2 in CO2-storage, in geothermal reservoirs with low permeability and in tight-gas-formations. |
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