US4228019A — Secondary recovery process

Claim 1

Independent Claim 156 words

A process for recovering hydrocarbons from a subterranean hydrocarbon-bearing fomration 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 a material selected from the group consisting of (I) ethylene oxide and (II) 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 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.

Claim 2

Dependent Claim 156 words

A process for recovering hydrocarbons from a subterranean hydrocarbon-bearing fomration 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 a material selected from the group consisting of (I) ethylene oxide and (II) 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 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.

Claim 3

Dependent Claim 13 words

The process of claim 1 wherein the said drive fluid contains a surfactant.

Claim 4

Dependent Claim 25 words

The process of claim 1 wherein the said drive fluid is saturated with carbon dioxide at a pressure of about 300 to about 3000 psig.

Claim 5

Dependent Claim 26 words

The process of claim 1 is wherein the said drive fluid is saturated with natural gas at a pressure of about 300 to about 3000 psig.

Claim 6

Dependent Claim 34 words

The process of claim 1 wherein the said drive fluid includes about 0.005 to 0.3 weight percent of an alkaline agent selected from the group consisting of sodium hydroxide, potassium hydroxide and sodium hypochlorite.

Claim 7

Dependent Claim 143 words

A fluid for use in recovering hydrocarbons from sub terranean 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 a material selected from the group consisting of (I) ethylene oxide and (II) 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 alkoxylated vinyl sulfonic acid units is about 5 to about 35 with the balance being units of acrylamide and wherein the average molecular weight of the said water-soluble copolymer is about 10,000 to about 2,000,000.

Claim 8

Dependent Claim 143 words

A fluid for use in recovering hydrocarbons from sub terranean 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 a material selected from the group consisting of (I) ethylene oxide and (II) 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 alkoxylated vinyl sulfonic acid units is about 5 to about 35 with the balance being units of acrylamide and wherein the average molecular weight of the said water-soluble copolymer is about 10,000 to about 2,000,000.

Claim 9

Dependent Claim 19 words

The fluid of claim 6 saturated with carbon dioxide at a pressure of about 300 to about 3000 psig.

Claim 10

Dependent Claim 19 words

The fluid of claim 6 saturated with natural gas at a pressure of about 300 to about 3000 psig.

Claim 11

Dependent Claim 32 words

The fluid of claim 6 wherein about 0.005 to about 0.3 weight percent of an alkaline agent selected from the group consisting of sodium hydroxide, potassium hydroxide and sodium hypochlorite is included.

Claim 12

Dependent Claim 30 words

The fluid of claim 6 wherein about 0.001 to about 1.0 weight percent of a surfactant selected from the group consisting of alkylaryl sulfonates and alkyl polyethoxylated sulfates is included.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1983-10-14	1984-04-14	1984-10-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1987-10-14	1988-04-14	1988-10-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1991-10-14	1992-04-14	1992-10-14	$7700.00	Window Closed / Lapsed

Secondary recovery process

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag