Study On The Stability Mechanism Of Foam Formation In A Complex System Of Nano-Particle-CO₂-Heavy Oil

In this paper,the nanoparticle-CO₂/light hydrocarbon-heavy oil complex system is taken as the research object,and the foam formation stability experiment and quantitative characterization of nanoparticle-CO₂-heavy oil system under non-equilibrium state are carried out and completed.The experimental results show that at a lower pressure drop rate,the volume height of the foam formed in the nanoparticle-CO₂-heavy oil system is higher and the existence time is longer.Si O₂ non-metallic oxide nanoparticles can effectively promote the formation of foam oil in CO₂-heavy oil system,and the effect of 0.2%（0.2 wt%）Si O₂ nanoparticles is the best.Mg O nanoparticles have a positive effect on foam formation,but little effect.Al₂O₃ nanoparticles are not conducive to the formation of foam.The addition of nanoparticles to the CO₂-heavy oil system can effectively improve the stability of the foam and prolong the existence time of the foam,and the metal nanoparticles have a stronger stabilizing effect on the foam than the non-metallic nanoparticles.On this basis,an exponential mathematical model for describing foam formation and rupture was established by using experimental data fitting method,and the physical significance of each parameter of the model was expounded.Meanwhile,On the basis of experiments,a new and practical method is proposed to quantify the gas dissolution and preferred mass transfer of nanoparticle-CO₂-heavy oil system under non-equilibrium conditions.More specifically,quasi-equilibrium boundary conditions,real gas equation,and Rayleigh distribution function are combined with the classical equation of motion,continuity equation,and mass transfer equation to form a novel equation matrix for quantifying gas bubble growth in foamy oil.The mathematiccal models of gas dissolution and preferred mass transfer between gas components and liquid phase in nanoparticle-CO₂-heavy oil system under non-equilibrium conditions was established theoretically.