COMPOSITION FOR OIL RECOVERY FROM NONUNIFORM OIL FORMATION Russian patent published in 2003 - IPC

FIELD: oil producing industry, particularly, oil recovery from nonuniform oil formation by means of injection of polymer solutions into formation. SUBSTANCE: composition includes mixture of anionic polymer and salt of polyvalent cation and water with content of salts of up to 280 g/l. Mixture has equivalent ratio of said cation to anionic link of polymer of 0.01-1.07 and pH 4-10, with the following amounts of components, wt.%: anionic polymer 0.001-0.08; salt of polyvalent cation 0.0005-0.002; the balance, said water. EFFECT: increased efficiency of development of nonuniform oil formation due to improved rheological properties of composition, extended field of application owing to utilization of mineralized water, and simplified technology of preparation of composition due to excluded alkalization. 2 tbl