Generalized Welge Construction for Two-Phase Flow in Porous Media in System with Limited Miscibility
F. Helfferich · SPE Annual Technical Conference and Exhibition · 1982
ABSTRACT The Welge construction to establish saturation profiles or histories in one-dimensional displacement of two completely immiscible phases in porous media is generalized for systems with limited miscibility of the two phases. The extension is applicable to any number of components, all of which may partition between the two phases. Instead of a diagram of fractional flow versus saturation of either phase in the conventional Welge construction, the extension uses a diagram of overall fractional flow versus overall volume fraction of an arbitrary component. The principle of construction remains the same. However, the different nature of the curve, in particular the discontinuities in slope, give rise to a more complex behavior. The various types of behavior which can occur in systems with S-shaped fractional flow curves within the two-phase region are discussed.