METHOD OF INCREASING OIL RECOVERY OF HYDROPHILIC FORMATIONS Russian patent published in 2016 - IPC E21B43/22 C09K8/584 C09K8/84 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to particular to methods of increasing reservoir recovery. In compliance with hydrophilic formations consisting of high-permeability and low-permeable interlayers and drilled over by injection and production wells, which involves pumping through injection well to formation during flooding of water solution of electrolyte-based solvent, a nonionic surfactant “NPAV” and water, forcing-through said solution inside formation, larger part of solution moves at high-permeability of stratum, displacing oil to face of production well, while smaller portion of said solution under action of pressure drop between highly and low-permeable interlayer is pressed in low-permeable interlayer by capillary impregnation to ensure reduction of surface tension at phase boundary residual brine water and oil in low-permeability interlayer hydrophilic header, then shutdown of injection well for process maintenance duration T_day, determined by distance of injection well to oil displacement front above water solution and piezo conductivity of formation T=l²×/2χ, where l is specified distance, m, χ - piezo conductivity of formation, m²/day, and further pumping of water flooding solution with subsequent extraction of oil through production wells as water solution of aqueous solution containing magnesium chloride as electrolyte, as liquid agent-acetone, with following ratio of components, vol%: magnesium chloride 5-10, acetone 40-60, “NPAV” 0.1, and water is balance.

EFFECT: increasing oil recovery of hydrophilic layers.

1 cl, 3 ex, 1 tbl, 5 dwg