METHOD OF PREPARING DEMULSIFIER Russian patent published in 2002 - IPC

FIELD: preparation of petroleum on oil fields for deep dehydration and demineralization of stable crude oil emulsions. SUBSTANCE: method of preparing demulsifier for dehydration of crude oil emulsion comprises condensing ethylene and propylene oxide blockcopolymer having average molecular weight of 4200 conventional units with modifying agent which is either dibasic adipic acid or phthalic anhydride at blockcopolymer to modifying agent molar ratio of 1:(0.5-1.2). Condensation product is mixed with organic solvent which is low-molecular alcohol or aromatic hydrocarbon or mixture thereof, ratios of components being as follows, wt %: condensation product 30-60 and solvent, 40-70. Solvent includes mixture of wt %: low-molecular alcohol, 10-90 and aromatic hydrocarbon, 10-90. Amount of water separated from crude oil- water emulsion is as high as 98.2 % (dehydration degree). EFFECT: greater activity of demulsifier.