Determination of the Binary Diffusion Coefficients and Interaction Viscosities of the Systems Carbon Dioxide–Nitrogen and Ethane–Methane in the Dilute Gas Phase from Accurate Experimental Viscosity Data Using the Kinetic Theory of Gases

Abstract

The results of viscosity measurements at moderate densities on the two gaseous mixtures carbon dioxide–nitrogen and ethane–methane including the pure gases between 253.15 K and 473.15 K, originally performed by Humberg et al. at Ruhr University Bochum, Germany, using a rotating-cylinder viscometer between 0.1 MPa and 2.0 MPa, were employed to determine the interaction viscosity, $$\eta _{12}^{(0)}$$ η 12 ( 0 ) , and the product of molar density and diffusion coefficient, $$(\rho D_{12})^{(0)}$$ ( ρ D 12 ) ( 0 ) , each in the limit of zero density. The isothermal viscosity data were evaluated by those authors with density series restricted to the second order at most to derive the zero-density viscosities and initial density viscosity coefficients, $$\eta _\textrm{mix}^{(0)}$$ η mix ( 0 ) and $$\eta _\textrm{mix}^{(1)}$$ η mix ( 1 ) , for the mixtures, as well as, $$\eta _i^{(0)}$$ η i ( 0 ) and $$\eta _i^{(1)}$$ η i ( 1 ) ($$i=1,2$$ i = 1 , 2 ), respectively, for the pure gases. Humberg et al. have already compared their $$\eta _\textrm{mix}^{(0)}$$ η mix ( 0 ) and $$\eta _i^{(0)}$$ η i ( 0 ) data for carbon dioxide–nitrogen and ethane–methane with corresponding viscosity values theoretically computed for the nonspherical potentials of the intermolecular interaction. Now we employed $$\eta _\textrm{mix}^{(0)}$$ η mix ( 0 ) and $$\eta _\textrm{mix}^{(1)}$$ η mix ( 1 ) as well as $$\eta _i^{(0)}$$ η i ( 0 ) and $$\eta _i^{(1)}$$ η i ( 1 ) in two procedures to derive $$\eta _{12}^{(0)}$$ η 12 ( 0 ) values. For this, we needed $$A_{12}^*$$ A 12 ∗ values (ratio between effective cross-sections of viscosity and diffusion). But the second procedure applying the initial density viscosity coefficients $$\eta _\textrm{mix}^{(1)}$$ η mix ( 1 ) and $$\eta _i^{(1)}$$ η i ( 1 ) failed to yield reasonable $$\eta _{12}^{(0)}$$ η 12 ( 0 ) values. The first procedure should provide the best results when it is possible to use $$A_{12}^*$$ A 12 ∗ values computed for the nonspherical potential. The effect is comparatively small if $$\eta _{12}^{(0)}$$ η 12 ( 0 ) is determined. But if $$(\rho D_{12})^{(0)}$$ ( ρ D 12 ) ( 0 ) is calculated from $$\eta _{12}^{(0)}$$ η 12 ( 0 ) using $$A_{12}^*$$ A 12 ∗ values for the nonspherical potential, the impact is several percent. Moreover, the experimentally based $$\eta _{12}^{(0)}$$ η 12 ( 0 ) and $$(\rho D_{12})^{(0)}$$ ( ρ D 12 ) ( 0 ) data agree with theoretically calculated values for the nonspherical potentials.

Study on Characteristics of Steam Chamber and Factors Influencing Nitrogen-Assisted Vertical–Horizontal Steam Drainage Development

“…The nitrogen located at the top of the steam chamber also plays a role in displacing crude oil downward, thereby enhancing the oil drainage capacity of the reservoir. Additionally, due to the similarity in viscosity between nitrogen and dry steam, as shown in Figure 17 [22], this characteristic can reduce the viscous fingering effect, stabilize the displacement front, and improve oil displacement efficiency. Within the steam-swept region, the wettability of the reservoir rock changes from oilwet to water-wet, and the residual oil at the top of steam chamber after gravity drainage is mainly distributed as 'isolated droplets' in the pore space [23].…”