METHOD FOR SELECTIVE ISOLATION OF HIGH-PERMEABLE INTERVALS IN WELL Russian patent published in 1997 - IPC

FIELD: mining industry. SUBSTANCE: method implies successive pumping of polymer water solutions and muriatic acid, and pumped between them is separator. Used as polymer water solution is 0.1-1.0% water solution of copolymer - product of hydrolysis of polyacrylonitrile which represents partially hydrolyzed polyacrylonitrile with rate of hydrolysis equal to 65%. Used as separator is light petroleum. Pumping of polymer water solution is carried out at pressure below threshold pressure differential at which low-permeable interval starts passing liquid through itself, and water solution of muriatic acid does this at pressure above aforesaid threshold pressure differential. EFFECT: higher efficiency. 2 cl, 1 tbl