Journal article
Unstable, Super Critical CO2-Water Displacement in Fine Grained Porous Media under Geologic Carbon Sequestration Conditions
Haldor Topsoe AS1
Curtin University2
University of Copenhagen3
CHEC Research Centre, Department of Chemical and Biochemical Engineering, Technical University of Denmark4
Department of Chemical and Biochemical Engineering, Technical University of Denmark5
Neutrons and X-rays for Materials Physics, Department of Physics, Technical University of Denmark6
Department of Physics, Technical University of Denmark7
In this study we investigated fluid displacement water with supercritical (sc) CO2 in chalk under conditions close to those used for geologic CO2 sequestration (GCS), to answer two main questions: How much volume is available for scCO2 injection? And what is the main mechanism of displacement over a range of temperatures? Characterization of immiscible scCO2 displacement, at the pore scale in the complex microstructure in chalk reservoirs, offers a pathway to better understand the macroscopic processes at the continuum scale.
Fluid behavior was simulated by solving the Navier-Stokes equations, using finite-volume methods within a pore network. The pore network was extracted from a high resolution 3D image of chalk, obtained using X-ray nanotomography. Viscous fingering dominates scCO2 infiltration and pores remain only partially saturated.
The unstable front, developed with high capillary number, causes filling of pores aligned with the flow direction, reaching a maximum of 70% scCO2 saturation. The saturation rate increases with temperature but the final saturation state is the same for all investigated temperatures. The higher the saturation rate, the higher the dynamic capillary pressure coefficient.
A higher dynamic capillary pressure coefficient indicates that scCO2 needs more time to reach capillary equilibrium in the porous medium.
Language: | English |
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Publisher: | Nature Publishing Group UK |
Year: | 2019 |
Pages: | 11272 |
ISSN: | 20452322 |
Types: | Journal article |
DOI: | 10.1038/s41598-019-47437-5 |
ORCIDs: | 0000-0001-5560-7676 , Andersson, M. P. , Sørensen, H. O. and Stipp, S. L. S. |