METHOD OF MUDDED FORMATIONS TREATMENT Russian patent published in 2001 - IPC

FIELD: oil-producing industry, particularly, methods of treatment of bottom-hole zones for their demudding. SUBSTANCE: method includes successive injection into well of surfactants, aqueous solutions of alkali metals and ammonium salts; their holding in formation for 8-12 h; injection of strong inorganic acid into formation of aqueous solution and holding for 2 h; subsequent completion of well. Surfactants are used in the form of anionic ones, for instance, sodium alkylarylsulfonate or sodium dodecyl sulfate, or sodium alkylbenzene sulfate, or cationic surfactants, for instance, alkylbenzeneperidinium chloride, or benzenesulfonate-1- methyl-2-heptadecyl-5-ethanol-2-imidazoline, or nonionic surfactant, for instance, hydroxyethylated monoalkylphenols, hydroxyethylated fat acids of 0.1-3-% concentration in volume of 0.3-0.6 cu. m/m of perforated thickness of producing formation. Aqueous solutions of alkali metals and ammonium salts are used in the form of sodium peroxycarbonate in amount of 6-10 wt.%, ammonium persulfate in amount of 15-30 wt.% and water, the balance. Aqueous solution of inorganic acid is used in the form of hydrochloric acid of 6-15-% concentration. EFFECT: higher efficiency of bottom-hole zone demudding. 3 cl, 1 tbl