Coreflood experiments were performed to investigate the effectiveness of methane flood in revaporization of condensate phase from cores. Condensate was accumulated dynamically in cores by reducing the flowing pressure below the dewpoint of the flowing gas mixture used. Two-phase flow was continued until steady state was reached where condensate reached its residual saturation. Methane was flooded through the core to assess the revaporization process.

Methane flooding revaporizes condensate from the core and restores the gas permeability to its initial value, but it is a slow process. Experimental results showed that revaporization of heavy components by methane is very slow process and may require several 10s or 100s of pore volumes to achieve. The revaporization of condensate is controlled by the partitioning of the hydrocarbon components into the flowing gas phase when the pressure is below the minimum miscibility pressure (MMP). Increasing methane pressure and flow rate expedites the revaporization of condensate.

The revaporization of the heavy components in the condensate phase was slightly affected by non-equilibrium behavior at the high flow rates. The return permeability ratio increases with methane volume injected and is relatively insensitive to flow rate, indicating that non-equilibrium effects are of secondary importance. The experimental studies showed promising results for field application.