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U.S. Department of Energy
Office of Scientific and Technical Information

Process for the secondary recovery of petroleum

Patent ·
OSTI ID:7093217
The amount of polymer in a polymer flood required for good mobility control was reduced by the use of two aqueous polymer slugs, where the polymer concentrations in the second slug was less than about one-third that of the initial concentrated slug but not in excess of 100 ppM. A Berea sandstone core (permeability 250 md) was flooded with brine (4 percent sodium chloride, 0.3 percent calcium chloride dehydrate), saturated with a refined oil (viscosity 6.5 cps), and waterflooded with the brine. Tertiary oil recovery treatment consisted of two polymer slugs composed of aqueous solutions of Pusher P 700 (the sodium salt of about 20 percent hydrolyzed, substantially linear, high molecular weight polyacrylamide). For a five-fold reduction in polymer concentration, over 70 percent of the initial mobility factor was retained. At a ten-fold dilution, the mobility factor was about 50 percent that of the original concentrated slug.
Assignee:
Dow Chemical Co.
Patent Number(s):
US 3687199
OSTI ID:
7093217
Country of Publication:
United States
Language:
English