Study On Oil-water Interface Behavior Of Surfactant In Crude Oil Emulsion

Surfactant is a unique type of organic compound,suitable surfactant can greatly reduce the interfacial tension of oil and water,and is one of the best choice to improve the transportation efficiency of crude oil.In the long-distance pipeline using emulsification,In the surfactant-polymer-crude oil mixed production fluid,the study of surfactant oil-water interface behavior and the effect of polymer on the surfactant oil-water interface behavior are all worthy of our deep research Subject.In this paper,anionic surfactant Daqing petroleum sulfonate PS,Xinjiang petroleum sulfonate KPS,zwitterionic surfactant alkylsulfobetaine ASB,xylene substituted alkylsulfobetaine 5.26-1,etc.were used as model compounds Taking Daqing crude oil and Xinjiang crude oil as the research objects;taking the crude oil produced liquid containing polymer as the research background,through the rotary drop interface tension meter Texas-500 c,the oscillatory dilational rheometer Data Physics OCA20,and the emulsion stability analyzer Turbiscan LAB and other experimental equipment,the parameters of interfacial tension,dilational modulus,phase angle,dilational elasticity,dilational viscosity,stability index and other parameters were measured,and a more reliable understanding of the construction of surfactant oil-water interface self-assembled film,detailed The research contents and achievements are as follows:(1)The effect of salinity on the interfacial tension of the mixed system of zwitterionic surfactant(ASB)and anionic surfactant(PS)was explored.It was proved that the electrostatic attraction of ASB molecules and PS molecules can produce a synergistic effect to reduce interfacial tension.Increase the Na Cl concentration to adjust the molecular size of PS to control the synergy between PS and ASB.Under high Na Cl concentration,the compound system can achieve ultra-low interfacial tension in a wide concentration range.(2)The effects of two polymers,partially hydrolyzed polyacrylamide(PHPAM)and hydrophobically modified polyacrylamide(HMPAM),on the oil-water interface behavior of surfactants were investigated,and a reasonable explanation for the difference between the two oil-water interface films was obtained.PHPAM affects the properties of the interface film through the insertion of polymer molecular chains in the surfactant interface adsorption layer.The presence of PHPAM may cause a decrease in dilational modulus and dilational elasticity;while HMPAM affects the properties of the interface film by forming an interface two-dimensional network structure with surfactant molecules,and its addition has a greater impact on the properties of the interface film.(3)The factors affecting the stability of the emulsion were explored,and the respective roles of surfactants and polymers in improving the stability of the emulsion were found.Surfactants can reduce the energy required for the formation of O/W emulsions.Polymers can reduce the collision probability of emulsion droplets by increasing the viscosity of the bulk phase,and increase the drainage resistance of the liquid film.Among them,the two-dimensional spatial network structure formed by the HMPAM and surfactant molecules at the oil-water interface and near the interface can also significantly enhance the liquid film strength of the emulsion.