摘要 |
Oil is recovered from an underground petroleum reservoir which contains a brine having a salinity of from 50 to 220 kg/m3 total dissolved solids by injecting an alkylarylpolyalkoxy sulfate or alkylpolyalkoxy sulfate surfactant that exhibits phase stability in the brine or diluted brine. The surfactant is injected in an aqueous solution which is prepared with diluted brine which has a salinity slightly less than that required to cause partitioning of the surfactant out of the aqueous phase into the oil-water interface or oil phase. The injection of surfactant is followed by the injecting of a driving slug comprised of either diluted brine or thickened diluted brine.
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