Effect Of An Amphoteric Surfactant And An Alkali Binary Compound System On The Emulsification Of Viscous Crude Oil

With the increase of energy demand,the extraction of conventional crude oil can no longer meet the development needs.However,viscous crude oil has high contents of gums,asphaltenes,and other heavy components,and exhibits the characteristics of high viscosity,high density and poor mobility.These have brought huge challenges to the extraction and transportation of viscous crude oil.Emulsion viscosity reduction and transportation technology is one of the heavy oil pipeline technology with development prospects.Viscous crude oil emulsification is a thick oil-in-water(O/W)emulsion with viscous crude oil and surfactants to form a stable,low viscosity and low resistance liquid.How to choose a suitable surfactant system and evaluate the influence of various factors on the viscosity and stability of O/W emulsion is the key to the successful application of the emulsion viscosity reduction and delivery technology.In this paper,firstly,the physical properties of viscous crude oil produced in Liaohe Oilfield was analyzed,and the best physical conditions of the viscous crude oil emulsification were determined.On this basis,the application of surfactant emulsification for viscous crude oil were researched.and its emulsification effect on heavy oil was evaluated from the measurement of viscosity,stability and droplet size of heavy oil emulsion.The viscosity reduction and stability of the viscous crude oil emulsion were evaluated by measurement of viscosity and particle size distribution.In the experiment,different types of non /anionic / zwitterionic surfactants were selected to carry out emulsification experiments on viscous crude oil to evaluate the emulsification effect of the surfactants.The surfactants were preferred,and the best mass fraction of the surfactants was preferred.The synergistic effects of inorganic bases and organic bases with the preferred surfactants were studied to determine the stability and viscosity of viscous crude oil O/W emulsions.The results showed that when the mass fraction of CAB-35 was0.75%,the emulsion viscosity was 17.79 m Pa·s.With the addition of TEOA,the electrostatic attraction between the positively charged quaternary amine and the negatively charged carboxyl group can improve the stability of the viscous crude oil emulsion,the water separation rate was reduced to 11.3%,and the viscosity reduction rate reaches 95.24%.In the CAB-35 compound system,with the addition of TEOA,the interface is the most active.Emulsion is easier to emulsify and its viscosity reduction rate is increased.The droplet particle size distribution study showed that the CAB-35 and TEOA binary compound system showed dynamic stability of the particle size of the emulsion over time.