Investigation of Two-Component Hydrocarbon Mixture Filtration in Porous Media

Natural-gas condensate is valuable raw for chemical and oil industries. In the process of gas-condensate reservoir exploitation, one has to deal with a product which changes its composition all the time. This is due to retrograde condensation phenomenon of reservoir hydrocarbon mixture during reservoir pressure decrease. With appearance of such condensate within reservoir porous space, fluid flowrate decreases and even ultimate extinction of filtration process takes place. A mathematical model is developed, which describes one-dimension filtration of two-component hydrocarbon mixture in porous media. Methane-n-butane mixture appears as model mixture for being a close approximation of real gas-condensate reservoir hydrocarbon mixture. Structurally, the model consists of two parts, namely, the hydrodynamic part, which describes the process of two-phase filtration in a porous medium in the Darcy law approximation, and the thermodynamic part, within which the equations of state for mixture are used to calculate the compressibility coefficients of the mixture and the parameters of phase equilibrium of the system in the vapor and liquid phases. The results of mathematical modeling are in good agreement with experimental research of filtration processes of methane-n-butane binary hydrocarbon mixture. Possibility of gas-condensate plug (each of dynamic and static) formation is shown. Wave impact on an active reservoir could be a way to increase production rate.