Secondary recovery process
AssigneeTexaco Development Corporation
InventorWalter D. Hunter
Life of this patent
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Abstract
Hydrocarbons are recovered from a subterranean hydrocarbon-bearing formation penetrated by an injection well and a production well by displacing hydrocarbons toward the production well using a drive fluid such as water thickened with a copolymer of (a) vinyl sulfonic acid alkoxylated with 2,3-epoxy-1-propanol and (b) acrylamide. Optionally, the drive fluid can be saturated with carbon dioxide and/or natural gas at the injection pressure.
Claims10
A process for recovering hydrocarbons from a subterranean hydrocarbon-bearing formation penetrated by an injection well and a production well which comprises:
- (A) injecting into the formation via an injection well a drive fluid comprising water having dissolved therein about 0.01 to about 5.0 weight percent of a water-soluble copolymer comprising repeating units of (a) vinyl sulfonic acid alkoxylated with about 2 to about 100 weight percent of 2,3-epoxyl-1-propanol and (b) acrylamide, wherein in the said water-soluble copolymer the weight percent of the alkoxylated vinyl sulfonic acid units is about 5 to about 35 with the balance being units of acrylamide and wherein the number average molecular weight of the said water-soluble copolymer is from about 10,000 to about 2,000,000,
- (B) forcing the said fluid through the formation, and
- (C) recovering hydrocarbons through the production well.
A fluid for use in recovering hydrocarbons from subterranean hydrocarbon bearing formations comprising water having dissolved therein about 0.01 to about 5.0 weight percent of a water-soluble copolymer comprising repeating units of (a) alkoxylated vinyl sulfonic acid and (b) acrylamide and wherein the vinyl sulfonic units are alkoxylated with about 2 to about 100 weight percent of 2,3-epoxy-1-propanol, wherein in the said water-soluble copolymer the weight percent of alkoxylated vinyl sulfonic acid units is about 5 to about 35 with the balance being units of acrylamide and wherein the number average molecular weight of the said water-soluble copolymer is from about 10,000 to about 2,000,000.
Dependencies are inferred from the claim text.