METHOD OF ACID TREATMENT OF BOTTOM-HOLE OIL FORMATION ZONE Russian patent published in 2000 - IPC

FIELD: oil producing industry; applicable in acid treatment of bottom-hole oil formation zone of producing and injection wells. SUBSTANCE: isolation of highly permeable zones with formed in formation foam solution and subsequent treatment of low permeable formation zones with acid solution are carried out by successive injection into well of neutral salt of carbonic acid and acid solution with addition of polyacrylamide in amount of 0.05-0.2 wt. %. In addition, prior to injection of acid solution into well, light oil is injected in amount of 0.05-0.1 of acid solution volume. Weight concentration of neutral salt of carbonic acid is determined on the basis of concentration of acid in acid solution from stoichiometric relations. EFFECT: higher efficiency of the method due to increased sweep in formation depth and higher selectivity of treatment. 2 cl, 2 tbl