TY - JOUR
T1 - A network flow model for the genesis and migration of gas phase
AU - Chang, Koukung Alex
AU - Lindquist, W. Brent
N1 - Funding Information:
Acknowledgements This research was started when the first author was on leave from the National Pingtung University of Education, Taiwan; the university’s support is gratefully acknowledged. The hospitality of the Department of Applied Mathematics and Statistics, State University of New York at Stony Brook is gratefully acknowledged. This research was partially funded by the National Sciences Council of the Republic of China under grant NSC96WFA0G00043.
PY - 2013/2
Y1 - 2013/2
N2 - We present a network flow model to compute transport, through a pore network, of a compositional fluid consisting of water with a dissolved hydrocarbon gas. The model captures single-phase flow (below local bubble point conditions) as well as the genesis and migration of the gas phase when bubble point conditions are achieved locally. Constant temperature computational tests were run on simulated 2D and 3D micro-networks near bubble point pressure conditions. In the 2D simulations which employed a homogeneous network, negligible capillary pressure, and linear relative permeability relations, the observed concentration of CO2 dissolved in the liquid phase throughout the medium was linearly related to the liquid pressure. In the case of no gravity, the saturation of the gas phase throughout the medium was also linearly related to the liquid pressure; under gravity, the relationship became nonlinear in regions where buoyancy forces were significant. The 3D heterogeneous network model had nonnegligible capillary pressure and nonlinear relative permeability functions. While 100 % of the CO2 entered the 3D network dissolved in the liquid phase, 25 % of the void space was occupied by gas phase and 47 % of the CO2 exiting the outlet face did so via the gaseous phase after 500 s of simulation time.
AB - We present a network flow model to compute transport, through a pore network, of a compositional fluid consisting of water with a dissolved hydrocarbon gas. The model captures single-phase flow (below local bubble point conditions) as well as the genesis and migration of the gas phase when bubble point conditions are achieved locally. Constant temperature computational tests were run on simulated 2D and 3D micro-networks near bubble point pressure conditions. In the 2D simulations which employed a homogeneous network, negligible capillary pressure, and linear relative permeability relations, the observed concentration of CO2 dissolved in the liquid phase throughout the medium was linearly related to the liquid pressure. In the case of no gravity, the saturation of the gas phase throughout the medium was also linearly related to the liquid pressure; under gravity, the relationship became nonlinear in regions where buoyancy forces were significant. The 3D heterogeneous network model had nonnegligible capillary pressure and nonlinear relative permeability functions. While 100 % of the CO2 entered the 3D network dissolved in the liquid phase, 25 % of the void space was occupied by gas phase and 47 % of the CO2 exiting the outlet face did so via the gaseous phase after 500 s of simulation time.
KW - Carbon dioxide sequestration
KW - Compositional flow
KW - Gas genesis
KW - Network flow model
UR - http://www.scopus.com/inward/record.url?scp=84872275761&partnerID=8YFLogxK
U2 - 10.1007/s10596-012-9314-2
DO - 10.1007/s10596-012-9314-2
M3 - Article
AN - SCOPUS:84872275761
VL - 17
SP - 67
EP - 81
JO - Computational Geosciences
JF - Computational Geosciences
SN - 1420-0597
IS - 1
ER -