A Study On Synergistic Demulsification Of Microwave-magnetic Nanoparticle

A large amount of emulsion is inevitably produced during the production and transportation of heavy oil,and the heavy oil emulsion usually has high stability and difficult to break.Therefore,the economic and effective demulsification technology has important practical significance for the treatment and transportation of heavy oil.In the previous research,the research group found that magnetic nanoparticles assisted microwave could significantly improve the demulsification effect of heavy oil O/W emulsion.However,the influence of microwave and magnetic nanoparticles parameters on the synergism demulsification,as well as the coalescence mechanism is still uncertainty and needs to be further studied,which provides an experimental and theoretical basis for the development and application of microwave-magnetic nanoparticle collaborative demulsification technology in heavy oil O/W emulsion.Firstly,the static stability evaluation of heavy oil O/W emulsion is evaluated based on the water diversion rate in this thesis.On this basis,the effect of the magnetic nanoparticles,the microwave,and the microwave-magnetic nanoparticles on the demulsification of heavy oil O/W emulsion is studied through laboratory experiments,and the demulsification mechanism is analyzed from the aspect of the emulsion micro-droplet and zeta potential.In addition,the magnetic nanoparticles and microwave parameters under the synergistic demulsification is optimized through experiments.Under the optimal demulsification conditions,the recycling effects of magnetic nanoparticles is studied by cyclic experiments.Finally,according to electromagnetic field theory and the heat transfer theory and the microscopic characteristics of heavy oil O/W emulsion,the mathematical model of the effect of microwave on the heavy oil O/W emulsion is established,the relevant parameters such as the electromagnetic field strength,dielectric parameters,and convective heat transfer coefficients in the model are determined through theoretical derivation and experimental measurement,and the mathematical model is numerically solved according to the fourth-order Runge-Kutta method,and the temperature distribution of the emulsion before and after the addition of magnetic nanoparticles is determined.The result of experimental and theoretical research show that: under a certain power,the water diversion rate of emulsion is significantly increased under the effect of microwave-magnetic nanoparticles cooperative demulsification.On the one hand,the promoting effect is due to the response behavior of magnetic nanoparticles under the microwave electromagnetic field,on the other hand,the magnetic nanoparticles can promote the “thermal effect ” of microwave demulsification;Under the optimal demulsification conduction,the water separation rate of the emulsion can reach 99.1% within 1 hour.The magnetic nanoparticles can be reused for 3 times and still have good demulsification performance.The corresponding water separation rate of the emulsion can reach 96.74%.It is feasible for the magnetic nanoparticles to assist microwave to achieve the efficient demulsification of heavy oil O/W emulsion;The magnetic nanoparticles can not only enhance the ability of the emulsion to absorb microwaves,but also generate a certain amount of heating through the effect of magnetic loss,resulting in higher temperature of the emulsion after the addition of the magnetic nanoparticles.Besides,synergistic demulsification can be performed at a lower temperature than the microwave demulsification alone.