METHOD OF PRODUCTION AND SEPARATION OF OIL Russian patent published in 2018 - IPC E21B43/22 E21B43/40 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil production and separation method. Method of extracting oil in which mineralized raw water having total dissolved solids content (“TDS”) greater than 5000 ppm is passed through an ion filter to form treated water with reduced degree of mineralization compared to the feed water, while a portion of the feed water does not pass through the ion filter to form a retentate having an increased degree of mineralization compared to the feed water, at least a portion of the treated water having a reduced degree of mineralization is used as an aqueous fluid having an ionic strength of not more than 0.15 mol/l and the total dissolved solids content of 200 to 10,000 ppm introduced into the oil reservoir, oil and water are extracted from the formation after introduction of the aqueous fluid into the formation, mixing a demulsifier and a brine solution having a total dissolved solids content greater than 10,000 ppm, with at least a portion of the oil and water recovered from the formation, and the oil is separated from the mixture of oil, water, a demulsifier and a saline solution, wherein at least a portion of the retentate is used as at least a portion of said brine. Invention is developed in depending points of the formula.

EFFECT: increasing the efficiency of processing during oil production.

24 cl, 12 dwg