Surfactant waterflooding with hydrocarbon slug
AssigneeMobil Oil Corporation
InventorsJerry M. Waite, Ralph F. Burdyn
Life of this patent
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Abstract
Surfactant waterflooding process involving the injection of a hydrocarbon slug followed by a surfactant slug and a mobility control slug. The hydrocarbon slug has a viscosity less than that of the reservoir oil and is injected within the range of 0.01-0.04 pore volume. The surfactant slug is injected in an amount within the range of 0.05-0.3 pore volume and exhibits a surfactant concentration within the range of 0.5-4.0 weight percent. At least a portion of the mobility control slug has a viscosity at least as great as the viscosity of the hydrocarbon slug.
Claims12
In the recovery of oil from a subterranean oil-containing reservoir penetrated by spaced injection and production system, the method comprising:
- a. injecting into said reservoir via said injection system a slug of hydrocarbon having a viscosity less than the viscosity of the reservoir oil in an amount within the range of 0.01-0.04 pore volume,
- b. thereafter injecting into said reservoir via said injection system an aqueous surfactant slug in an amount within the range of 0.05-0.3 pore volume, said surfactant slug containing a surfactant within a range of 0.5-4.0 weight percent,
- c. thereafter injecting into said reservoir via said injection system an aqueous mobility control slug, at least a portion of said mobility control slug having a viscosity at least as great as the viscosity of said hydrocarbon slug,
- d. thereafter injecting into said reservoir via said injection system an aqueous flooding medium to displace oil to said production system, and
- e. recovering oil from said production system.
Dependencies are inferred from the claim text.