METHOD OF INCREASE OF OIL RECOVERY FROM OIL FIELDS DEVELOPED BY FLOODING Russian patent published in 1999 - IPC

FIELD: oil-producing industry; applicable in injection wells on oil fields developed by flooding. SUBSTANCE: wells are divided into groups on the basis of results of determination of their intake capacity. Viscoelastic compounds with different structural and mechanical properties are prepared for each group of wells. Viscoelastic compound is injected into tubing string with closed well annular space. Viscoelastic compound is forced into well bottom-hole formation zone by displacing fluid. Volume of viscoelastic compound of the first type is determined by formula, and that of the second type is reduced by a factor of 2, as compared with that of the first type. Volume of the third type is equal to that of the first type. At the moment of entering of viscoelastic compound of the second type into bottom-hole formation zone, wellhead pressure is less than the initial one by 0.1-0.5 MPa, and entering of the third type of viscoelastic compound into bottom-hole formation zone results in wellhead pressure drop below that of the second type by 0.5 MPa. EFFECT: higher volumes of recovery of hydrocarbon fluids. 6 cl