TY - JOUR
T1 - Comparison of CO2 trapping in highly heterogeneous reservoirs with Brooks-Corey and van Genuchten type capillary pressure curves
AU - Gershenzon, Naum I.
AU - Ritzi, Robert W.
AU - Dominic, David F.
AU - Mehnert, Edward
AU - Okwen, Roland T.
N1 - We thank the Editor and reviewers for comments and suggestions used to improve this manuscript. This work was supported as part of the Center for Geological Storage of CO 2 , an Energy Frontier Research Center funded by the U.S. Department of Energy , Office of Science, Basic Energy Sciences under Award # DE-SC0C12504 . We acknowledge Schlumberger Limited for the donation of ECLIPSE Reservoir Simulation Software. We thank Daniel Klen for manuscript editing. Both the data and input files necessary to reproduce the simulations are freely available from the authors upon request ([email protected]).
PY - 2016/10/1
Y1 - 2016/10/1
N2 - Geological heterogeneities affect the dynamics of carbon dioxide (CO2) plumes in subsurface environments in important ways. Previously, we showed how the dynamics of CO2 plumes are influenced by the multiscaled sedimentary architecture in deep brine fluvial-type reservoirs. The results confirm that representing small-scale features and the corresponding heterogeneity in saturation functions, along with hysteresis in saturation functions, are all critical to understanding capillary trapping processes. Here, we show that when heterogeneity and hysteresis are represented, the two conventional approaches for defining saturation functions, Brooks-Corey and van Genuchten, represent fundamentally different physical systems. The Brooks-Corey approach represents heterogeneity in entry pressures, and leads to trapping by capillary pinning. The van Genuchten approach represents a network of pores transporting the nonwetting fluid, across rock types, with negligible capillary entry pressure, and leads to capillary retardation. These differences significantly affect the large-scale characteristics of CO2 plumes (i.e., their mass, shape, and position).
AB - Geological heterogeneities affect the dynamics of carbon dioxide (CO2) plumes in subsurface environments in important ways. Previously, we showed how the dynamics of CO2 plumes are influenced by the multiscaled sedimentary architecture in deep brine fluvial-type reservoirs. The results confirm that representing small-scale features and the corresponding heterogeneity in saturation functions, along with hysteresis in saturation functions, are all critical to understanding capillary trapping processes. Here, we show that when heterogeneity and hysteresis are represented, the two conventional approaches for defining saturation functions, Brooks-Corey and van Genuchten, represent fundamentally different physical systems. The Brooks-Corey approach represents heterogeneity in entry pressures, and leads to trapping by capillary pinning. The van Genuchten approach represents a network of pores transporting the nonwetting fluid, across rock types, with negligible capillary entry pressure, and leads to capillary retardation. These differences significantly affect the large-scale characteristics of CO2 plumes (i.e., their mass, shape, and position).
KW - Brooks-Corey
KW - CO geosequestration
KW - Capillary trapping
KW - Heterogeneity
KW - Sedimentary architecture
KW - van Genuchten
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U2 - 10.1016/j.advwatres.2016.07.022
DO - 10.1016/j.advwatres.2016.07.022
M3 - Article
AN - SCOPUS:84980350882
SN - 0309-1708
VL - 96
SP - 225
EP - 236
JO - Advances in Water Resources
JF - Advances in Water Resources
ER -