Reduced-basis methods (RB) have demonstrated their efficiency for a wide variety of problems, most of which are elliptic PDEs solved by finite element methods. In this work, we attempt to apply the RB philosophy to a simple “real-life” model for two-phase flows in porous media, whose reference scheme is a finite volume method. This model is parameterized by the viscosity of water. Because of the mixed parabolic-elliptic nature of the system, we first propose to restrict the RB approach to the pressure subsystem corresponding to the end time. The resulting parametric dependence is, however, much more intricate than in the classical examples. This difficulty will be discussed and illustrated by numerical results.