The Research Of Heavy Oil Emulsification Ability And W/O Emulsion Stability

In the lifting process,heavy oil is easy to form emulsion whose viscosity can be used to choose the heating switch and the heating temperature.But the different emulsification ability of the heavy oils makes it difficult to control heating condition.So,we choose eight heavy oils of shengli oil field as research objects aiming at analyzing the reason of different heavy oil have different emulsion ability which is characterized by the moisture inverted point.The result of the research offer theoretical direction in choosing exploiting condition.Temperature and viscosity are chosen to analyze the change law of the moisture inverted point,and HLB value measuring method is established to determine and explain why different heavy oil has different inverted point from the perspective of oil-water interface.Achievements are as follows,on the one hand,heavy oil moisture inverted point gradually increase with the increase of temperature and with the decrease of heavy oil viscosity.And is the temperature boundary,under the increase rate of moisture inverted point is lager than that of upper 40?.When the viscosity is increased the emulsion viscous multiples of the same moisture content will increase and the emulsion viscous multiples of their own inverted point will decrease.On the other hand,on the basis of HLB measure mechanism,the interface is consist of asphalt aggregate,polar functional group and chain link between asphalt aggregate which is the weakest one of the three constituent parts determining the moisture inverted point.So the larger the HLB value is,the more hydrophilic the heavy oil will be,and the stronger the interaction between asphalt aggregate is,and the more hydrones the emulsion will have,and then the bigger the moisture inverted point is.Most of heavy oil extraction fluids exist in the form of W/O emulsion,which make the gathering and processing more difficult.So,all sorts of demulsification are used.But the stability of the produced fluid is different from each other,which make the demulsification method and conditions are hard to control.The reason of different heavy oils have different emulsion ability which is characterized by SV value is studied,and the suitable demulsifiers to ordinary and ultra heavy oil are screened and the demulsification mechanism are studied in order to offer theoretical direction in choosing demulsification condition.Research results are as follows,on the one hand,the smaller and more uniform the droplet size is and the more serious the multiple emulsion is the more stable the emulsion will be.Interface expansion modulus,interfacial tension and zeta potential interaction influence the stability of emulsion,and the stronger the interface expansion modulus is,the smaller the interfacial tension is,and the greater the zeta potential is,the more stable the emulsion will be.Especially the expansion of modulus has good correlation with the SV value.On the other hand,the demulsification effect of nonionic demulsifier is better than that of ionic demulsifier,which can significantly reduce the oil-water interfacial tension,interfacial expansion modulus and zeta potential.And the effect of demulsification achieved mainly by reducing the interface membrane of ordinary heavy oil and by reducing the zeta potential of ultra heavy oil.