METHOD OF WORKING A CRUDE OIL DEPOSIT Russian patent published in 1996 - IPC

FIELD: petroleum production. SUBSTANCE: method of working crude oil deposits with elevated petroleum viscosity, when internal water loading into low- drainable beds reduces petroleum mobility, comprises pumping in aqueous alkali-polymer solution and water through forcing bore hole and extracting crude oil through well. Alkali-polymer solution additionally has liquid hydrocarbon fraction originating from petroleum processing containing at least 15% aromatic hydrocarbons. Ratio of solution components ranges from 1: 1: 0.5 to 1: 1:5. Amount of pumped in solution constitutes 0.01-0.1 of the pore volume of processed bed. After pumping in of the solution is finished, forcing bore hole is left for a time necessary for reagents to interact. As a polymer polyacrylamide is used. Liquid hydrocarbon fraction may be pumped in either in mixture with alkali-polymer solution or later. Polyacrylamide-alkali-hydrocarbon mixture brought in contact with petroleum and mineralized bed water produces a stable emulsion containing suspended dispersions of metal hydroxides. EFFECT: reduced permeability of flooded bed, reduced viscosity of crude oil, increased phase permeability of rock through crude oil. 2 cl, 1 tbl