METHOD OF REGULATING OIL FORMATION PERMEABILITY Russian patent published in 2016 - IPC E21B43/20 C01D3/04 C01D3/06 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to chemistry and oil industry, specifically to methods for displacement of residual oil from strata with inhomogeneous permeability, and can be used for salt treatment of oil-containing formation, represented by inhomogeneous permeability carbonate or terrigenous reservoirs. Method involves pumping into formations aqueous salt solutions containing chlorides, characterised by that it includes first pumping into formation solution of sodium and/or potassium, and/or calcium, and/or magnesium chloride with total content of salts of 60-200 g/l at pH 6.5-7.5, then formation is treated with sulphuric acid solution.

EFFECT: uniform treatment of all stagnant zones of formation, higher efficiency and degree of oil recovery of oil-containing formation, as well as removal of sulphur from oil directly in productive formation.

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