Condensate System In The Phase Of Theoretical Research And Application In Gas Field Development In Porous Media

At present, test and analysis methods of condensate and gas without the interfacial phenomenon affect of porous media are very perfect. However, thousandth and unseen rock pore is made up of store up and preserve space of oil and gas reservoirs. Is there variance between the phase behaviors of condensate gas in PVT and that in the porous medium? How about the difference? This is the problem that the technicians ponder over all through and the main content of this paper.This paper based on the study of phase in and aboard, especially the study of our Gas Reservoirs Engineering Lab in recent decade. Description of porous medium, affect of porous medium interfacial phenomenon on phase behaviors, and the affect of porous medium interfacial phenomenon on exploitation dynamic state are studied studied, and so on.Theoretical basis of thermodynamics on fluid phase balance is studied in this paper, and estimating rule of thermoelectrical equilibrium with interfacial phenomena is analyzed. Adsorption theoretical model is evaluated on the base of essential theory of adsorption. The theory model of cavern solution is uesd to compute adsorption of condensate gas in porous medium. Crystal lattice theroy adosrption model is used to compute adsorption of condensate oil on surface of porous medium. Adsorption of binary liquid phase is calculated according to the data of gas phase adsorption. This is the input data of multicompositinoal liquid phase adsorption. Crystal lattice theroy adosrption model is applied to study multielement liquid phase adsorption. This paper considers the mixer of gas-liquid phase adsorption at the first time, and using the critical flowing saturation of condensate oil as the judgement for deciding the adsorption caused by mixer or only liquid phase.In order to complete the example computing, adsorption potential theory of Dubinin is used to established the extend model of adsorption isotherm on the base of experimental data existing. The adsorption isotherm of all components at 90℃.In the affect of porous medium interfacial phenomenon on condensate gas phase behaviors, the model of dew point considering the adsorption and capillary force simultaneous is established, and the programmer of this work had been finished. The dew point affected by the porous had been calculated too.Original composition of oil and gas is thought to be gas-liquid phase and adsorption phase. In practice, if the pressure tested is higher than the dew point pressure, condensate is one phase in the porous medium, so we should consider the gas adsorption to calculate the original composition; if the pressure tested is lower than dew point, condensate consist in both gas and liquid phase, we should consider the mixer of gas and liquid to calculate the original composition.Constant Volume Depletion (CVD) computing is the one of the important content to study phase behaviors, so the models of CVD according to the pressure is higher or lower than the dew point respectively. When the pressure is higher than the dew point, the system of condensate gas is gas phase, so the theory model of cavern solution should be use to compute gas adsorption. When the pressure is lower than the dew point, because of the condensate oil condensating from the gas, the system consist in gas and liquid phase. Now, if the retrograde condensate saturation is lower than the critical flowing saturation of condensate oil, the model of the mixer of gas-liquid phase adsorption should be applied; if the retrograde condensate saturation is higher than the critical flowing saturation of condensate oil, the condensate oil can flow on the interface of the porous medium, at this condition, gas adsorption should not be considered, and should...