LAUSR

Nonionic polyacrylamide with the weight-average molecular mass of 7 MDa was modified by sulfomethylation. The composition of sulfomethylated polyacrylamides was determined by iodometric titration, Fourier IR spectroscopy, thermal gravimetric analysis, and elemental analysis. The sulfomethylated acrylate polymers containing ≥19.9 mol % sulfo groups are resistant to brines containing up to 70 g L–1 CaCl2 at temperatures of up to 140°С and to hydrothermal treatment at 180°С. As shown by capillary turbulent rheometry under the conditions of thermal, salt, and acid aggressions, at the optimum concentrations of sulfomethylated polyacrylamide in the medium, сopt = 0.025–0.085%, the maximal extent of a decrease in the hydrodynamic resistance, DRmax, remains on the level of 71–80%, and the flow rate increment, ΔQ, is on the level of (22.01–28.85) × 10–6 m3 s–1.