| In order to better understand thestability mechanism of heavy oil produced liquid in Tahe reservoir and provide theoretical guidance for efficient demulsification,this thesis used viscoelastic interface instrument,interfacial tensionmeasurement,Zeta potentialnano particle analyzer to study the interfacial shear viscosity and interfacial tension(IFT)between simulated water and simulated oil withasphaltene,resin or wax isolated from Tahe heavy oil,the Zeta potential and stability of the emulsion,The results show thattheasphaltene and resin components contained many surface active substances,therefore their IFT was low,Interfacial shear viscosity is higher and interfacial films with certain structures ccould form.Therefore,colloid and asphaltene can form a stable O/W emulsion and W/O emulsion,wax component can not form a stable emulsion.Because the asphaltene is the key factors affecting tahe crude oil emulsion stability and It has a strong association,At the state of dispersion and the associated state,it has important significance in Viscosity reduction and emulsificationOf heavy oil.By dissolving different concentrationsof asphaltene in mixtures of xylene and kerosene with different mixed ratios,the influence of interfacial properties between simulated water and simulated oil on emulsionstability was investigated in detail.When the asphaltene was dissolved in different simulated oil,its dispersion state was different..The asphaltene could totally be dissolved in xylene.As the concentration of asphaltene increased,the IFT decreased,and the interfacial shear viscosity and the strength of interfacial film increased,suggesting that as the concentration of asphaltene increased,the amount of asphaltene assembling at the interface increased,that is to say,there were more surface active substances.In the asphaltene,xylene and kerosene system(the volume ratio of xylene and kerosene was 3:7),when the concentration of asphaltene was 20.0 mg/L,the interficial stracture was most compact and the interficial film was the strongest,indicating that the interficial adsorption of asphaltene was not only related to the concentration of asphaltene,but also to its micromorphology in oil and the microstructure at the oil/water interface.When the amount of kerosene was reduced,the solubility of asphaltene increased,while its adsorption at the interface decreased,which demonstrates that the oil property could affect the adsorption of asphaltene at the interface and the structure and strength of the interficial film.the dispersion state of the asphaltene in organic solvent has a great influence on the interfacial properties of oil and waterTheoreticallyand furtheraffectedthe stability of the emulsion.The stability of emulsionis not only related to the property of oil/water interface,but also to the dispersed state and associating state of asphaltene. |
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