Revaporization of Condensate with Methane Flood

摘要

Coreflood experiments were performed to investigate therneffectiveness of methane flood in revaporization of condensaternphase from cores. Condensate was accumulated dynamicallyrnin cores by reducing the flowing pressure below the dewpointrnof the flowing gas mixture used. Two-phase flow wasrncontinued until steady state was reached where condensaternreached its residual saturation. Methane was flooded throughrnthe core to assess the revaporization process.rnMethane flooding revaporizes condensate from the corernand restores the gas permeability to its initial value, but it is arnslow process. Experimental results showed thatrnrevaporization of heavy components by methane is very slowrnprocess and may require several 10s or 100s of pore volumesrnto achieve. The revaporization of condensate is controlled byrnthe partitioning of the hydrocarbon components into thernflowing gas phase when the pressure is below the minimumrnmiscibility pressure (MMP). Increasing methane pressure andrnflow rate expedites the revaporization of condensate.rnThe revaporization of the heavy components in therncondensate phase was slightly affected by non-equilibriumrnbehavior at the high flow rates. The return permeability ratiornincreases with methane volume injected and is relativelyrninsensitive to flow rate, indicating that non-equilibrium effectsrnare of secondary importance. The experimental studiesrnshowed promising results for field application.