4 Results and Discussion: Fluid
Transport
4.1 Fluid Transport in HH
Nanopores
In this section, we report on the hydrocarbon and water velocity
profiles with different accelerations (0.0005, 0.001, and 0.002
nm/ps2) at 350 K and 400 atm. This would be analogous
to imposing advective flow on the fluid confined within the pores. The
velocity profile is obtained applying the bin method91which is shown in Supporting Information.
We present the water (Fig. 7a) and hydrocarbon (Fig. 7b) velocity
profiles at 0.0005 nm/ps2 in the 5 nm HH nanopore.
Because the hydrocarbon and water velocity profiles at the acceleration
of 0.001 nm/ps2 and 0.002 nm/ps2show similar trends with that of 0.0005 nm/ps2, they
are not shown here and provided in Fig.S4 in Supporting Information.
Fig. 7a indicates that the water velocity changes with increasing water
concentration directly as a result of the growth in the thickness of the
adsorbed layer of water as shown in Fig. 8. A thicker adsorbed layer
impedes flow. At 100% water, we observe the classical parabolic
signature of liquid flow in slit-pores.
Fig. 7b indicates that increasing water concentration promotes
hydrocarbon flow up to a point. The initial increase has been attributed
to the creation of smooth surfaces following adsorption of
water69. Subsequent increases decrease the effective
flow radius for hydrocarbon flow as shown in Fig. 8, leading to a
decline of hydrocarbon velocity.