Synthesis And Properties Of Demulsifier Based On Hydrophobic Associated Polymer Extraction

In enhanced oil recovery (EOR), polymer flooding is an effective development technology to improve oil production. It has been recognized around the world by it’s high oil recovery efficiency and high economic efficiency. Hydrophobically Associating Polymer (HAP) refers to a water-soluble polymer with a small amount of hydrophobic groups on the polymer hydrophilic macro molecules. When dissolved in water, it can exhibit special rheology and good salt resistance those are different from the general water-soluble polymer. To a certain extent, HAP with these features can overcome the shortcomings of the conventional polymer with low temperature and salt tolerance and easy shear degradation in the oil and gas exploration. So HAP is widely used in oil fields in recent years. But HAP also brought malpractice that its recovery is very stable emulsion, so that conventional demulsifier has a low efficiency, affecting the normal oil productioaFor HAP Flooding emulsion breaking problems, the effects of crude oil components and HAP on the stability of crude oil emulsion of HAP flooding were investigated by bottle-test method. Parameters such as interfacial tension, interfacial electrical, interfacial expansion rheology and interfacial shear viscosity were used to characterize the oil-water interfacial properties of the HAP flooding emulsion. Series of nonionic and cationic demulsifiers were synthesized for the simulation emulsions. Demulsification of demulsifier and complex matching for HAP produced fluid were examinedThe results showed that among the crude oil components, resin and asphaltene were the most important factors influencing the stability of the emulsion. Within a certain range of concentration, emulsion stability was enhanced as the HAP concentration increased. Microscopic interfacial properties of the test showed that HAP can absorb at oil-water interface and reduce the interfacial energy, which contributed to emulsification. It was supposed that HAP molecules can form a network structure on the oil-water interface. Thus the modulus of interfacial expansion rheology and interfacial shear viscosity were increased, and the electronegativitied of the oil-water film were enhanced, which may result in a more stable emulsion. The phenol-amine resin block polyether demulsifiers and polyethylene imine block polyether demulsifiers with initiator content 0.5%, m(EO)/m(PO)=1/1 showed the lowest interfacial tension, highest interface activity and best effect of macroscopic demulsification. The microscopic interface properties was consistent of macroscopic demulsification results. Complex matching of demulsifiers can improved crude oil emulsion by increasing the removal rate of water and oil.