METHOD OF WATER-FLOODING OF OIL FORMATION Russian patent published in 2001 - IPC

FIELD: oil production; applicable for increasing oil recovery from nonuniform permeable formation and reduction of rate of water encroachment of wells. SUBSTANCE: method includes injection of aqueous suspension of polyacrylamide through injection well. Polyacrylamide is preliminarily mixed with powdery cellulose ether with degree of substitution by carboxymethyl groups of 0.65-1.45 and degree of polymerization of 600-100. Cellulose ether is used in the form of cross-linked polyacrylamide. Carboxymethyl cellulose-polyacrylamide ratio is from 1:1 to 2:98. EFFECT: higher efficiency of water-flooding process of oil formation and intensified oil recovery due to increased thermal stability of working solutions and their preset rheological properties in mixing with mineralized water. 4 cl, 2 tbl, 1 ex