METHOD FOR TREATMENT OF INJECTION WELL Russian patent published in 1995 - IPC

FIELD: oil producing industry. SUBSTANCE: method for treatment of injection well includes alternate injection into formation of process solutions possessing alkali, neutral and acid medium reactions, at constant pressure with subsequent injection of spacer fluid with medium reaction close to neutral equalling 0.2-2.0 volumes of process solution, and then, spacer fluid is withdrawn in the volume equalling its injected volume, and treatment of well with process solution, which is injected according to stabilization of injection flow rate. In so doing, process solution possessing acid reaction is used in form of compound containing sodium bisulfate, potassium oxygen-containing salts, surfactant and water, or mineral acids or their salts, surfactant and water, or salts of sulfur-oxygen containing acids, surfactant and water. Process solution possessing alkali reaction is used in form of compound containing sodium and/or potassium and/or ammonium hydrocarbonate, surfactant and water, and in the end, removed from well are process solution and spacer fluids up to obtaining the formation fluid. EFFECT: efficient action on mud fill of inorganic and organic compositions of technogenic origin. 7 cl, 10 tbl