| abstract |
Extraction of oil by flooding with aq. dispersion of nonionic surfactants consisting of glyco-lipids of formula (I) or (II) In the formulae, glycosidic 1,2; 1,3; 1,4 and 1,6 bonds are present in anomeric alpha and beta forms; in (II) the branching in the oligo-saccharide is in anomeric alpha and beta forms; R1 and R2 in positions 2,3,4 are in cis and trans configuration; R1 and R2 are OH, alkoxy, alkoxy, alkylcarbonyloxy, alkyl carboxamido, or amino; R3 is -CH2OH, -CH2NH2, alkoxy-, alkyl carbonyloxy- or alkylcarboxamide-N-methylene, COOH, CONH2, alkoxycarbonyl or N-alkyl carboxamide; the alkyl gps. are 6-80C; n is 1.5-5; m is 1-3. No deposit causing blocking of the pores is formed with Ca, Mg or Fe ions in the formation water. Little or no increase in viscosity, requiring excessive injection pressure, is caused. The dispersions are easily prepd. and micro-emulsion additives are not needed. |