PROCESS OF STABILIZATION OF MODIFIED POLYACRYLAMIDE Russian patent published in 2004 - IPC

FIELD: oil industry, development of oil fields with use of physical and chemical methods of increase of oil recovery from oil pools, specifically, to oil-driving reagents for inhomogeneous flooded formations. SUBSTANCE: technical result of invention consists in increase of thermal oxidizing stability of modified polyacrylamide in fresh and highly mineralized water, in improvement of its rheological properties with high displacement stresses and in rise of productivity of wet method of stabilization of polymer subjected to ionizing radiation. Process of stabilization of modified polyacrylamide includes preliminary cross-linking of polyacrylamide under action of ionizing radiation and its subsequent treatment with aqueous solution of secondary amides and formaldehyde at temperature of 20-80 C. Concentration of formaldehyde in aqueous solution amounts to 1.5-5.0 per cent by mass or 0.1-0.5 mole/kg of polyacryamide and of secondary amines 0.8-2.5 per cent by mass or 0.01-0.04 mole/kg of polyacrylamide. In the capacity of secondary amines there are utilized water-soluble derivatives of diphenylamine: N-phenyl-o-phenyldiamine, or N-methyl-phenyldiamine, or N,N'-diacetyl-o- phenyldiamine, or N-acetyl-β-napthylamine. Above-mentioned treatment is conducted with medium pH 8.0-10.0 by mixing in dryers for loose materials under vacuum in the course of 1.5-2.0 h. EFFECT: increased thermal oxidizing stability of modified polyacrylamide. 3 cl, 1 dwg, 1 tbl