METHOD FOR TREATMENT OF NONUNIFORM OIL BED Russian patent published in 1998 - IPC

FIELD: oil production industry. SUBSTANCE: method implies successive injection into oil bed of hydrocarbon solution of surface-active substance and acid composition. Used in function of surface-active substance are oxyethylated isononilphenols with degree of oxyethylation of 3-5 and/or monoalkyl ester of polyethyleneglycol on basis of primary fatty alcohols of general formula C_nH_2n+1O(C₂H₄O)H,, where n = 10-18, = 3-5, and used in function of acid composition is water solution of muriatic acid, sulfite liquor, surface-active substance and solvent or water solution of lignosulfonate, acid-containing solvent, surface-active substance and muriatic acid or composition of water solution of muriatic and hydrofluoric acids, solvent, surface-active substance and inorganic salts or muriatic acid, or mixture of muriatic and hydrofluoric acids. In preferable version of realizing aforesaid method, hydrocarbon solution of surface-active substance and acid composition are taken in ratio of 3:1 - 1:5. Application of aforesaid method ensures reduction of flooding of recovered product and increase of oil recovery. EFFECT: higher efficiency. 1 cl, 1 tbl, 3 ex