Secondary recovery process
AssigneeTexaco Development Corporation
InventorWalter D. Hunter
Life of this patent
Estimating the term…
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 acrylamide and vinyl sulfonic acid or salts thereof alkoxylated with an alkylene oxide. 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 of acrylamide-vinyl sulfonic acid or the sodium, potassium or ammonium salt thereof alkoxylated with a material selected from the group consisting of (a) ethylene oxide and (b) a mixture of ethylene oxide and propylene oxide, wherein in the said mixture the weight percent of ethylene oxide is about 60 to about 95, wherein in the said water-soluble copolymer the weight percent of the acrylamide units is about 65 to about 95 with the balance being units of vinyl sulfonic acid or the sodium, potassium or ammonium salt thereof 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 of acrylamide-vinyl sulfonic acid or the sodium, potassium or ammonium salt thereof alkoxylated with about 2 to about 100 weight percent of a material selected from the group consisting of
- (a) ethylene oxide and
- (b) a mixture of ethylene oxide and propylene
- oxide and wherein in the said mixture the weight percent of ethylene oxide is about 60 to about 95, wherein in the said water-soluble copolymer the weight percent of the acrylamide units is about 65 to about 95 with the balance being units of vinyl sulfonic acid or the sodium, potassium or ammonium salt thereof and wherein the number average molecular weight of the said water-soluble copolymer is about 10,000 to about 2,000,000.
Dependencies are inferred from the claim text.