FIELD: oil and gas production. SUBSTANCE: oil-containing water is treated with effective amount of water-soluble cationic polymer dispersion. The latter is prepared via polymerization of water-soluble monomers' mixture containing at least 5 mol.% of cationic monomer and at least 5 mol.% of metacrylamide in aqueous solution of inorganic salt with polyvalent anion. Polymerization is carried out in presence of polymer dispersant constituting a water- soluble cationic polymer which is soluble in the above-mentioned inorganic salt solution and contains at least 20 mol/% of cationic monomer distinguishing from that contained in monomers' mixture. EFFECT: enhanced efficiency of process. 6 cl, 2 dwg, 1 tbl
