Positive coupling effect in gas condensate flow: Role of capillary number, Scheludko number and Weber number

Abstract

The coupled flow in gas condensate reservoirs is investigated using a purely theoretical approach for the description of velocity effect on relative permeability in the absence of inertial effects. A combination of linear stability analysis and dynamic wetting theory is used to describe this coupled flow under the effect of viscous resistance and disjoining pressure. The role of capillary number and Scheludko number (i.e. the dimensionless ratio of disjoining pressure to capillary pressure) is clearly expressed through closed relative permeability formula for the limits of negligible and strong disjoining effect. The model predicts no velocity dependence at very low capillary numbers and a positive velocity effect at high capillary numbers but the negative velocity effect at very high velocities due to strong inertial effects is not predicted due to the model's basic assumptions. Although the model was not intended to serve as a substitute for the experiment, reasonable quantitative agreement is observed between its predictions and available experimental data as long as the Weber number (the dimensionless ratio of inertial resistance to capillary pressure) is smaller than 5 × 10−5, with an average and a maximum relative deviation of 16% and 67% respectively, for a total number of 49 data points.