Patent ID: 8631868

Claim:
A method of extracting oil from an oil containing subterranean formation comprising: providing, through a first borehole, a pressurized floodwater that comprises about 50 ppm to about 5,000 ppm guanidyl copolymer; and recovering oil from the subterranean formation through a second borehole; wherein the guanidyl copolymer is a condensation product of a guanidyl reactant selected from the group consisting of guanidine, guanidine salt, cyanamide, dicyanamide, biguanide, guanylurea, guanylthiourea, polycyclic guanidine, N-(4-aminobutyl)guanidine, 2-amino-5-guanidinopentanoic acid, imidodicarbonimidic diamide, (N-butylimidocarbonimidic diamide), (2-(methylguanidino) ethanoic acid), (2-[carbamimidoyl(methyl)amino]ethyl dihydrogen phosphate), cyanoguanidine, (2-guanidinoacetic acid), (3-(diaminomethylideneamino)propanoic acid), (N,N-dimethylimidodicarbonimidic diamide), (1-nitroguanidine), (4-amino-N-[amino(imino)methyl]benzenesulfonamide), (2-[10-(diaminomethylideneamino)decyl]guanidine dihydrochloride), melamine, alkyl guanidine, aryl guanidine, alkylaryl guanidine, alkyl biguanide, aryl biguanide, alkylaryl biguanide, and a mixture thereof; and a carbonyl reactant selected from the group consisting of an aldehyde, a ketone, a urea, an amide, and a mixture thereof.