COMPOSITION FOR DEHYDRATION AND DESALTING OF CRUDE OIL (EMBODIMENTS) Russian patent published in 2007 - IPC C10G33/04 C08G18/48 

FIELD: crude oil treatment.

SUBSTANCE: invention provides composition of demulsifier used to separate formation water from produced water-oil emulsion. According to first embodiment of invention, composition contains, wt %: nonionic demulsifier based on block copolymers of oxyethylated and oxypropylated propylene or ethylene glycol, 10-25; ethylene oxide/propylene oxide block copolymer based on glycerol with number of ethylene oxide units 1-30 and propylene oxide units 50-80 and having molecular mass 3000-6000, 10-25; oxyethylated polyether resin having molecular mass 4000-6000, 5-15; cross-linked alkylene oxide block copolymers, 5-15; solvent: heavy oil solvent "Nefras A-120/200" blended with superheavy oil solvent "Nefras A-150/330", 10-50; and water-soluble solvent such as methanol or isopropyl alcohol, or butyl cellosolve, 1050. According to second embodiment, composition is the same as above except nonionic demulsifier based on block copolymers of oxyethylated and oxypropylated propylene or ethylene glycol replaced by nonionic demulsifier based on polyglycol Dowfax 70 N14, 10-25%.

EFFECT: increased low-temperature demulsification efficiency, especially for high-viscosity emulsions formed by heavy oils, with preserved demulsification efficiency at elevated temperatures.

2 cl, 1 tbl, 390 ex