| abstract |
A method for improving the mobility and pipeline transport of a viscous crude oil by forming an oil-in-water emulsion with said oil and from 20 to 80% by weight of water in the presence of 170 to 4000 parts by weight per million parts by weight of oil of a surfactant blend, said blend comprising from 30 to 70 parts by weight of an anionic or amphoteric surfactant (A) selected from those of the formulae Ar(OCH2CH2)nOSO3H,Ar(OCH2CH2)nOCH2COOH, R<1)<OCH2CH2)nOCH2COOH, <IMAGE> a sodium and ammonium salt thereof, and from 30 to 70 parts by weight of a nonionic surfactant selected from (B) of the formula Ar(OCH2CH2)pOH or (C) of the formula <IMAGE> the latter having an HLB value of from 10 to 20; where Ar is octylphenyl or nonylphenyl, n is 2 to 10, p is 10 to 100, m is 20 to 40, r is 20 to 50, R<1> is C8 to C18 alkyl and R<2> is C12 to C18 alkyl. |