Displacement of oil from rock formations by flooding - with aq. solns. of nonionic glyco-lipid surfactants

摘要

Oil is displaced from underground formations by flooding with aq. dispersions of non-ionic glyco-lipid surfactants of formula (I) or (II): (in which the glycosidic bonds 1,1; 1,2; 1,3; 1,4; and 1,6 are in the anomeric alpha, alpha; alpha, beta or beta, beta forms and groups R1 to R3 in positions 1,2,3 or 4 are in cis- or trans configuration; R1 to R3 are OH, alkoxy, alkylcarboxamido, or amino; R4 is -CH2OH, -CH2NHi, alkoxy-, alkyl-carbonyloxy- or alkylcarboxamide-N-methylene; COOH, CONH2, alkoxycarbonyl or N-alkyl carboxamide; the alkyl or alkoxy groups contain 8-60 c atoms). The dispersions are simple to prepare and use, requiring no addn. of oil or derivs., thickeners, etc. Viscosity is not increased by the surfactants, so that excessive injection pressure are avoided. No pption and blocking of the pores occurs in presence of Ca, Mg and/or Fe ions in the formation wateR, resulting in increased oil yieldS.