CPC C09K 8/588 (2013.01) [E21B 43/168 (2013.01)] | 20 Claims |
1. A method of recovering oil from a hydrocarbon-bearing subterranean geologic formation, the method comprising:
producing a first hydrocarbon composition from the hydrocarbon-bearing subterranean geologic formation;
injecting a first injection fluid comprising a first viscoelastic polymer and a first brine solution into the hydrocarbon-bearing subterranean geologic formation,
wherein the first viscoelastic polymer has a shear viscosity from 500 to 700 cP at a shear rate of 0.5 to 2 s−1,
producing a second hydrocarbon composition from the hydrocarbon-bearing subterranean geologic formation;
injecting a second injection fluid comprising a viscous polymer and a second brine solution into the hydrocarbon-bearing subterranean geologic formation,
wherein the viscous polymer has a shear viscosity greater than the first viscoelastic polymer,
producing a third hydrocarbon composition from the hydrocarbon-bearing subterranean geologic formation;
injecting a third injection fluid comprising a second viscoelastic polymer and a third brine solution into the hydrocarbon-bearing subterranean geologic formation,
wherein the second viscoelastic polymer has a shear viscosity less than the viscous polymer,
producing a fourth hydrocarbon composition from the hydrocarbon-bearing subterranean geologic formation.
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