METHOD OF PREPARING DEMULSIFIER FOR DEHYDRATION AND DEMULSIFICATION OF WATER-OIL EMULSIONS Russian patent published in 2001 - IPC

FIELD: crude oil treatment. SUBSTANCE: invention, in particular, relates to demulsifier for extensive dehydration and desalting of persistent emulsions of high-viscosity crude oils with elevated content of suspended impurities. Demulsifier is prepared by interaction of branched polyether with p-toluylenediisocyanate and starch at molar ratio 1:(1-2):1, respectively, at stirring, said polyether being in turn prepared by alcoholate polymerization of propylene oxide or ethylene oxide/propylene oxide with glycerol or by alcoholate polymerization of propylene oxide with glycerol followed by block copolymerization with ethylene oxide. Interaction product is then mixed with phosphorylated linear polyether prepared by phosphorylation of polyether with dimethyl phosphite optionally followed by amination at weight ratio of interaction product to linear polyether (0.5-10):(10-0.5). Phosphorylated linear polyether is preferably used in the form of 50±5 wt % solution in aqueous methanol. Demulsifier is used in the form of solution in organic solvent. EFFECT: increased efficiency of dehydration and desalting providing simultaneous protection against corrosion. 3 cl, 3 tbl, 64 ex