251. Characterizing the Dissolution Rate of CO2-Brine in Porous Media under Gaseous and Supercritical Conditions
- Author
-
Pengfei Lv, Yu Liu, Ying Teng, Dayong Wang, Tingting Luo, Jia-nan Zheng, Wu Bohao, Xingbo Li, and Lanlan Jiang
- Subjects
Materials science ,010504 meteorology & atmospheric sciences ,02 engineering and technology ,micro–computed tomography ,lcsh:Technology ,01 natural sciences ,Physics::Geophysics ,lcsh:Chemistry ,Physics::Fluid Dynamics ,symbols.namesake ,porous media ,CO2 storage ,General Materials Science ,dissolution rate ,Porosity ,lcsh:QH301-705.5 ,Instrumentation ,Dissolution ,Astrophysics::Galaxy Astrophysics ,Physics::Atmospheric and Oceanic Physics ,0105 earth and related environmental sciences ,Fluid Flow and Transfer Processes ,lcsh:T ,Process Chemistry and Technology ,General Engineering ,Reynolds number ,Saline aquifer ,021001 nanoscience & nanotechnology ,heterogeneity ,lcsh:QC1-999 ,Supercritical fluid ,Computer Science Applications ,lcsh:Biology (General) ,lcsh:QD1-999 ,Chemical engineering ,lcsh:TA1-2040 ,symbols ,Imbibition ,Astrophysics::Earth and Planetary Astrophysics ,lcsh:Engineering (General). Civil engineering (General) ,0210 nano-technology ,Saturation (chemistry) ,Porous medium ,lcsh:Physics - Abstract
The CO2-brine dissolution homogenizes the distribution of residual CO2 and reduces the leakage risk in the saline aquifer. As a key parameter to immobilize the free CO2, the dissolution rate of CO2-brine could be accelerated through mechanisms like diffusion and dispersion, which are affected by the subsurface condition, pore structure, and background hydrological flow. This study contributed the calculated dissolution rates of both gaseous and supercritical CO2 during brine imbibition at a pore-scale. The flow development and distribution in porous media during dynamic dissolution were imaged in two-dimensional visualization using X-ray microtomography. The fingerings branching and expansion resulted in greater dissolution rates of supercritical CO2 with high contact between phases, while the brine bypassed the clusters of gaseous CO2 with a slower dissolution and longer duration due to the isolated bubbles. The dissolution rate of supercritical CO2 was about two or three orders of magnitude greater than that of gaseous CO2, while the value distributions both spanned about four orders of magnitude. The dissolution rates of gaseous CO2 increased with porosity, but the relationship was the opposite for supercritical CO2. CO2 saturation and the Reynolds number were analyzed to characterize the different impacts on gaseous and supercritical CO2 at different dissolution periods.
- Published
- 2017
- Full Text
- View/download PDF