COMPOSITION FOR TREATMENT OF OIL FORMATIONS Russian patent published in 2003 - IPC

FIELD: oil producing industry, particularly, compositions for treatment of oil formations to limit water inflow to producing wells and to increase oil recovery. SUBSTANCE: composition contains the following amounts of components, wt. %: bioreagent KShAS-M - product of vital activity of bacterium species of pseudomonas aeruginosa S-7 40-50; oil- soluble nonionic surfactant 9-12; demulsifier 1-3; the balance, hydrocarbon solvent. EFFECT: simple in composition and facilitated in manufacture composition, offering high efficiency for increase of oil recovery from water- encroached formations at late stage of development under conditions of formation waters of various mineralization. 2 tbl