The present work is devoted to mathematical modeling of the wave filtration process. It is shown that periodic solutions can arise in the retrograde region of the phase diagram. The article shows the existence of a pulsational character of the filtration regime of the flow of a hydrocarbon mixture, the occurrence of which in practice can be explained by the constant inflow of heavy components into the bottomhole zone, and then by their condensation, which leads to an increase in the volume of the liquid phase. Further, when a sufficient amount of liquid is accumulated and its mobility increases, it comes to the well, the saturation profile flattens out and the process repeats. The solution of the system of differential equations for the filtration of a gas-condensate mixture in a porous medium taking into account the nonequilibrium of phase transitions is made by the finite element method in the FlexPDE package.