Geological carbon storage (GCS) involves unstable drainage processes, the formation of patterns in a morphologically unstable interface between two fluids in a porous medium during drainage. The unstable drainage processes affect CO2 storage efficiency and plume distribution and can be greatly complicated by the mixed-wet nature of rock surfaces common in hydrocarbon reservoirs where supercritical CO2 (scCO2) is used in enhanced oil recovery. Here, we performed scCO2 injection (brine drainage) experiments at 8.5 MPa and 45°C in heterogeneous micromodels, two mixed-wet with varying water- and intermediate-wet patches, and one water-wet. The flow regime changes from capillary fingering through crossover to viscous fingering in the micromodels of the same pore geometry but different wetting surfaces at displacement rates with logCa (capillary number) increasing from –8.1 to –4.4. While the mixed-wet micromodel with uniformly distributed intermediate-wet patches yields ~0.15 scCO2 saturation increase at both capillary fingering and crossover flow regimes (–8.1 ≤ logCa ≤ –6.1), the one heterogeneous wetting to scCO2 results in ~0.09 saturation increase only at the crossover flow regime (–7.1 ≤ logCa ≤ –6.1). The interconnected flow paths in the former are quantified and compared to the channelized scCO2 flow through intermediate-wet patches in the latter by topological analysis. At logCa > –6.1 (near well), the effects of wettability and pore geometry are suppressed by strong viscous force. Both scCO2 saturation and distribution suggest the importance of wettability on CO2 storage efficiency and plume shape in reservoirs and capillary leakage through caprock at GCS conditions.
Chang, Chun, et al. "Impacts of Mixed-Wettability on Brine Drainage and Supercritical CO<sub>2</sub> Storage Efficiency in a 2.5-D Heterogeneous Micromodel." Water Resources Research, vol. 56, no. 7, Apr. 2020. https://doi.org/10.1029/2019wr026789
Chang, Chun, Kneafsey, Timothy J., Wan, Jiamin, Tokunaga, Tetsu K., & Nakagawa, Seiji (2020). Impacts of Mixed-Wettability on Brine Drainage and Supercritical CO<sub>2</sub> Storage Efficiency in a 2.5-D Heterogeneous Micromodel. Water Resources Research, 56(7). https://doi.org/10.1029/2019wr026789
Chang, Chun, Kneafsey, Timothy J., Wan, Jiamin, et al., "Impacts of Mixed-Wettability on Brine Drainage and Supercritical CO<sub>2</sub> Storage Efficiency in a 2.5-D Heterogeneous Micromodel," Water Resources Research 56, no. 7 (2020), https://doi.org/10.1029/2019wr026789
@article{osti_1638208,
author = {Chang, Chun and Kneafsey, Timothy J. and Wan, Jiamin and Tokunaga, Tetsu K. and Nakagawa, Seiji},
title = {Impacts of Mixed-Wettability on Brine Drainage and Supercritical CO<sub>2</sub> Storage Efficiency in a 2.5-D Heterogeneous Micromodel},
annote = {Geological carbon storage (GCS) involves unstable drainage processes, the formation of patterns in a morphologically unstable interface between two fluids in a porous medium during drainage. The unstable drainage processes affect CO2 storage efficiency and plume distribution and can be greatly complicated by the mixed-wet nature of rock surfaces common in hydrocarbon reservoirs where supercritical CO2 (scCO2) is used in enhanced oil recovery. Here, we performed scCO2 injection (brine drainage) experiments at 8.5 MPa and 45°C in heterogeneous micromodels, two mixed-wet with varying water- and intermediate-wet patches, and one water-wet. The flow regime changes from capillary fingering through crossover to viscous fingering in the micromodels of the same pore geometry but different wetting surfaces at displacement rates with logCa (capillary number) increasing from –8.1 to –4.4. While the mixed-wet micromodel with uniformly distributed intermediate-wet patches yields ~0.15 scCO2 saturation increase at both capillary fingering and crossover flow regimes (–8.1 ≤ logCa ≤ –6.1), the one heterogeneous wetting to scCO2 results in ~0.09 saturation increase only at the crossover flow regime (–7.1 ≤ logCa ≤ –6.1). The interconnected flow paths in the former are quantified and compared to the channelized scCO2 flow through intermediate-wet patches in the latter by topological analysis. At logCa > –6.1 (near well), the effects of wettability and pore geometry are suppressed by strong viscous force. Both scCO2 saturation and distribution suggest the importance of wettability on CO2 storage efficiency and plume shape in reservoirs and capillary leakage through caprock at GCS conditions.},
doi = {10.1029/2019wr026789},
url = {https://www.osti.gov/biblio/1638208},
journal = {Water Resources Research},
issn = {ISSN 0043-1397},
number = {7},
volume = {56},
place = {United States},
publisher = {American Geophysical Union (AGU)},
year = {2020},
month = {04}}
Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, Vol. 245, Issue 1242, p. 312-329https://doi.org/10.1098/rspa.1958.0085
ASME 2015 International Mechanical Engineering Congress and Exposition, Volume 10: Micro- and Nano-Systems Engineering and Packaginghttps://doi.org/10.1115/IMECE2015-50657