| 摘要 |
1476940 Oil recovery MARATHON OIL CO 29 July 1974 [10 Aug 1973] 33332/74 Heading E1F A method of recovering oil from an oilbearing subterranean formation comprising injecting into the formation an aqueous composition containing at least two different petroleum sulphonates, each petroleum sulphonate having an average equivalent weight of from 395-450 and an aliphatic to aromatic proton ratio of from 4:1 to 20:1, the two sulphonates having aliphatic to aromatic proton ratios differing one from the other by at least 2.5. Preferably the aqueous composition contains 1-25% by volume of the petroleum sulphonates and is an emulsion or a micellar dispersion. A mobility buffer slug may be injected into the formation after the aqueous composition. Conventional additives may be added such as hydrocarbons, e.g. crude oil, a partially refined fraction of crude oil, a refined fraction of crude oil, synthetic hydrocarbons (including halogenated hydrocarbons) or unreacted hydrocarbon within the petroleum sulphonate; cosurfactants, e.g. an amine, ketone, alcohol, C 1-20 ester or ether, or similar compound containing one or more hydroxy, oxy, amide or halide groups; electrolytes, e.g. an inorganic acid, inorganic base or inorganic salt; viscosity increasing agents, e.g. polysaccharides; and mobility reducing agents, e.g. acrylamide polymers, copolymers of acrylamide and acrylic acid or sodium acrylate, or N-sulpho-hydrocarbon-substituted acrylamides.
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