Deformation Medium Condensate Gas Reservoirs Of Oil And Gas Phase Equilibrium Of Systems Theory And Applied Research

The theoretical and applied study on phase equilibrium of gas condensate system in deformable media is a leading edge theme which is of difficulty and multidisciplinary cross, but of highly theoretical and practical value.the phase equilibrium of gas condensate take place in reservoir which is defomalbe and porous media, reservoir distortion results in average pore radius,pore volume,specific surface and surface area varying with effective stress. the result is that the process of depletion is a reducing process of pore volume in physics,not a constant volume process,and the effect of capillary condensation, capillary force, interfacial adsorption varying with variation of average pore radius,specific surface and surface area too. these characters is not only different from the normal measurement and calculation method but also different from characteristic in indeformable and porous media. on the basis of experimental and theoretical research about phase equilibrium laws in porous and indeformable media, the mathematical models of phase equilibrium considering reservoir deformation ,capillary condensation, capillary force, interfacial adsorption are constructed and the program is developed. then phase behavior considering single factor is researched and the mechanism is analysed. In the end, phase behavior of gas condensate considering all of factors is researched. the main innovation work are as follows.(1)the dynamic models about physical parameters of rock are constructed, in combination with stress sensitivity measurement ,the tendency varying with effective stress about average pore radius, specific surface and surface area is analysed(2)the model of adsorption isotherm in deformable media is construcetd and adsorption isotherm of pure component is generated.(3)the dew point calculation model considering capillary condensation and reservoir deformation is constructed and the law of dew point pressure is analysed.the calculation model of CCE considering capillary force and reservoir deformation is constructed and phase behavior is analysed.(4)the mathematical model of phase equilibrium simulating depletion process considering pore volume change and capillary force is constructed and phase behavior is analysed.(5)the mathematical model of composition restoration considering interfacial adsorption in deformable media is constructed and real composition is restored.the calculation model about dew point pressure considering reservoir deformation,capillary condensation and interfacial adsorption is constructed and dew point pressure at reservoir temperature is calculated.the calculation model about depletion considering reservoir deformation,capillary force and interfacial adsorption is constructed and phase behavior of gas condensate at reservoir temperature is researched and analysed.In the end ,it comes to the conclusion that the phase behavior of gas condensate considering effect of reservoir deformation,capillary force,capillary condensation and interfacial adsorption is not only notably different from phase behavior in PVT cell but also remarkably different from phase behavior in indeformable and porous media. therefore,it is...