%0 Journal Article
%A Zhu, Guangpu
%A Yao, Jun
%A Li, Aifen
%A Sun, Hai
%A Zhang, Lei
%D 2017
%T Pore-Scale Investigation of Carbon Dioxide-Enhanced
Oil Recovery
%U https://acs.figshare.com/articles/journal_contribution/Pore-Scale_Investigation_of_Carbon_Dioxide-Enhanced_Oil_Recovery/4829134
%R 10.1021/acs.energyfuels.7b00058.s001
%2 https://acs.figshare.com/ndownloader/files/8010976
%K contact angle
%K CO 2 sequestration
%K Carbon Dioxide-Enhanced Oil Recovery Carbon dioxide
%K CO 2 breaks
%K phase field method
%K CO 2
%K oil recovery
%K CO 2 displacement phenomena
%K oil recovery increases
%K CO 2 flow path decreases
%X Carbon dioxide (CO2) enhanced
oil recovery is a green
and promising way to produce oil and reduce the rapid growth of carbon
dioxide released to atmosphere. A pore-scale understanding of CO2 displacement phenomena is important to enhance oil recovery
in porous media. In this work, a direct numerical simulation method
is employed to investigate the drainage process of CO2 in
an oil-wet porous medium. The interface between the oil and CO2 is tracked by the phase field method. The capacity and accuracy
of the model are validated using a classic benchmark: the process
of a bubble rising. A series of numerical experiments were performed
over a large range of values of the gravity number, capillary number,
and viscosity ratio to investigate the flooding process of CO2 in a porous medium. The results show that the pressure in
the main CO2 flow path decreases dramatically after CO2 breaks through the outlet. Oil begins to reflow into large
pores that were previously occupied by CO2. This phenomenon
has an important impact on the final saturation distribution of CO2. Increasing the viscous force is the dominant mechanism for
improving oil recovery. Selecting an appropriate depth is the primary
consideration for reaching the maximum recovery before CO2 is injected into the subsurface. Abnormal high-pressure formations
represent a good choice for CO2 sequestration. Gravity
fingers improve the sweep area of CO2 when the viscous
force is small. The oil recovery increases with increasing contact
angle. It is difficult to reach the final steady state of saturation
because of the “snap-off and supplement” dynamic balance
in porous media when both the injection velocity and the contact angle
are small.
%I ACS Publications