Waterflood mobility control - by following aq. polymer slug with soln. of alkali metal hypochlorite

摘要

Secondary oil recovery procedure by waterflooding using (1) a slug of a dilute aq. polymer soln. and (2) a slug of a dilute aq. alkali metal hypochlorite soln., opt. followed by (3) an aq. drive. The pref. polymer is a high mol.wt. partially hydrolysed polyacrylamide; the pref. hypochlorites are Na, Li and K. Pref. concentrations are 0.01-0.15 wt.% in (1) and 0.5-2 wt.% in (2) and pref. quantities 10-35% pore volume of (1) and 10-25% pore volume of (2). Improved displacement and sweep efficiencies and higher recovery volumes are obtd.