STIMULI-DEGRADABLE GELS

• US 20070277981A1
• Filed: 06/02/2006
• Published: 12/06/2007
• Est. Priority Date: 06/02/2006
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Robb, Ian D., Saini, Rajesh K., Sarkar, Diptabhas, Todd, Bradley L., Griffin, James M.
• Granted Patent: US 7,306,040 B1
• Time in Patent Office: Days
• US Class Current: 166/300
• CPC Class Codes: C09K 8/035 Organic additives
• CPC Class Codes: C09K 8/512 containing cross-linking agents
• CPC Class Codes: C09K 8/685 containing cross-linking agents

Abstract

Some methods are provided that comprise: providing a treatment fluid comprising an aqueous fluid, and a stimuli-degradable gel formed by a reaction comprising a gelling agent, and a stimuli-degradable cross linking agent that includes at least one degradable group and two unsaturated terminal groups; placing the treatment fluid into a subterranean formation; and allowing the stimuli-degradable gel to degrade.

Claims

1. A method comprising:

providing a treatment fluid comprising an aqueous base fluid, and a stimuli-degradable gel formed by a combination of a gelling agent, and a stimuli-degradable cross linking agent described by the following formula;

R¹-[A]-[R³]—

[B]—

R²

wherein R¹ and R² may be the same or different, and comprise at least one group selected from the group consisting of;

a substituted or unsubstituted ethylenically unsaturated group, N-acryl, O-acryl, acryloyl, vinyl, allyl, melamide, a derivative thereof, and a combination thereof;

A and B comprise optional bridging units; and

R³ comprises a degradable group or polymer; and

placing the treatment fluid into a subterranean formation.

2. The method of claim 1 wherein the gelling agent comprises at least one gelling agent selected from the group consisting of:

an ethylenically unsaturated monomer of the general formula CH₂═

CXY, wherein X and Y may be hydrogen, an alkoxy amide group, or an acetamides group;

ethylene;

propylene;

butene-1;

vinyl cyclohexane;

vinyl cyclohexene;

styrene;

vinyl toluene;

an ionizable monomer;

1-N,N-diethylaminoethylmethacrylate;

diallyldimethylammonium chloride;

2-acrylamido-2-methyl propane sulfonate;

acrylic acid;

2-acrylamido-2-methyl propane sulfonate;

acrylic acid;

an allylic monomer;

di-allyl phthalate;

di-allyl maleate;

allyl diglycol carbonate;

vinyl formate;

vinyl acetate;

vinyl propionate;

vinyl butyrate;

crotonic acid;

itaconic acid;

vinyl fluoride;

vinyl chloride;

vinylidine;

fluoride;

tetrafluoroethylene;

acrylamide;

methacrylamide;

methacrylonitrile;

acrolein;

methyl vinyl ether;

ethyl vinyl ether;

vinyl ketone;

ethyl vinyl ketone;

allyl acetate;

allyl propionate;

diethyl maleate;

a diene monomer;

butadiene;

isoprene;

chloroprene;

a derivative thereof; and

a combination thereof.

3. The method of claim 1 wherein R³ comprises at least one group selected from the group consisting of:

an esters, a phosphate ester, an amide, an acetal, a ketal, an orthoester, a carbonate, an anhydride, a silyl ether, an alkene oxide, an ether, an imine, an ether ester, an ester amide, an ester urethane, a carbonate urethane, an amino acid, a derivative thereof, and a combination thereof.

4. The method of claim 1 wherein a G′

of the treatment fluid at a first time is greater than the G′

of the treatment fluid at a later second time because of the degradation of the stimuli-degradable gel.

5. The method of claim 1 wherein A or B comprises at least one group selected from the group consisting of:

a peptide chain, an aromatic substituent, an alkyl group, an alkylene group, a polar group, and a derivative thereof.

6. The method of claim 1 wherein the cross linking agent is synthesized from diketene acetals or multiketene acetals by the addition of monohydric alcohol having acrylic, vinylic, or allylic groups.

7. The method of claim 6 wherein the monohydric alcohol comprises at least one monohydric alcohol selected from the group consisting of:

hydroxyethylacrylate;

hydroxypropyl methacrylamide;

hydroxybutyl methacrylate; and

glycerol monomethacrylate.

8. The method of claim 1 wherein the cross linking agent is formed by a reaction comprising a monohydric alcohol that contains a vinyl, allyl, or allylic group and a low molecular weight orthoester of Formula I:

wherein R is H, CH₃, or C₂H₅, and R₄ is an alkyl group having from about 1 to about 6 carbon atoms.

9. The method of claim 1 wherein the cross linking agent is water soluble.

10. The method of claim 1 wherein the treatment fluid is foamed and comprises a surfactant.

11. A method comprising:

providing a treatment fluid comprising an aqueous fluid, and a stimuli- degradable gel formed by a reaction comprising a gelling agent, and a stimuli-degradable cross linking agent that includes at least one degradable group and two unsaturated terminal groups;

placing the treatment fluid into a subterranean formation; and

allowing the stimuli-degradable gel to degrade.

12. The method of claim 11 further comprising reducing the pH of the treatment fluid before allowing the stimuli-degradable gel to degrade.

13. The method of claim 11 further comprising subjecting the treatment fluid to a temperature change before allowing the stimuli-degradable gel to degrade.

14. The method of claim 11 wherein the degradable group comprises at least one degradable group selected from the group consisting of:

an ester, a phosphate ester, an amide, an acetal, a ketal, an orthoester, a carbonate, an anhydride, a silyl ether, an alkene oxide, an ether, an imine, an ether ester, an ester amide, an ester urethane, a carbonate urethane, an amino acid, a derivative thereof, and a combination thereof.

15. The method of claim 11 wherein a G′

of the treatment fluid is reduced upon degradation of the stimuli-degradable gel.

16. The method of claim 11 wherein at least one of the unsaturated terminal groups comprises at least one group selected from the group consisting of:

a substituted or unsubstituted ethylenically unsaturated group, a vinyl group, an allyl group, an acryl group, an unsaturated ester, an acrylate, a methacrylate, a butyl acrylate, an amide, an acrylamide, an ether, a vinyl ether, a combination thereof, and a derivative thereof.

17. The method of claim 11 wherein the gelling agent comprises at least one gelling agent selected from the group consisting of:

an ethylenically unsaturated monomer of the general formula CH₂═

CXY, wherein X and Y may be hydrogen, an alkyl group, an aryl group, an alkoxy group, a carboxylic acid group, an amide group, an alkoxy amide group, an acetamide group, an ester, or an ether;

ethylene;

propylene;

butene-1;

vinyl cyclohexane;

styrene;

vinyl toluene;

an ionizable monomer;

1-N,N-diethylaminoethylmethacrylate;

diallyldimethylammonium chloride;

2-acrylamido-2-methyl propane sulfonate;

acrylic acid;

2-acrylamido-2-methyl propane sulfonate;

acrylic acid;

an allylic monomer;

di-allyl phthalate;

2-acrylamido 2-methyl propane sulfonic acid, acrylic acid, di-allyl maleate;

allyl diglycol carbonate;

vinyl formate;

vinyl acetate;

vinyl propionate;

vinyl butyrate;

crotonic acid;

itaconic acid;

vinyl fluoride;

vinyl chloride;

vinylidine;

fluoride;

tetrafluoroethylene;

acrylamide;

methacrylamide;

methacrylonitrile;

acrolein;

methyl vinyl ether;

ethyl vinyl ether;

vinyl ketone;

ethyl vinyl ketone;

allyl acetate;

allyl propionate;

diethyl maleate;

a diene monomer;

butadiene;

isoprene;

chloroprene;

a derivative thereof; and

a combination thereof.

19. The method of claim 17 wherein at least one of the unsaturated terminal groups comprises at least one group selected from the group consisting of:

a substituted or unsubstituted ethylenically unsaturated group, a vinyl group, an allyl group, an acryl group, an unsaturated ester, an acrylate, a methacrylate, a butyl acrylate, an amide, an acrylamide, an ether, a vinyl ether, a combination thereof, and a derivative thereof.

20. The method of claim 17 wherein the gelling agent comprises at least one gelling agent selected from the group consisting of:

an ethylenically unsaturated monomer of the general formula CH₂═

CXY, wherein X and Y may be hydrogen, an alkyl group, an aryl group, an alkoxy group, a carboxylic acid group, an amide group, an ester, an ether, an alkoxy amide group, or an acetamide group;

ethylene;

propylene;

butene-1;

vinyl cyclohexane;

vinyl cyclohexene;

styrene;

vinyl toluene;

an ionizable monomer;

1-N,N-diethylaminoethylmethacrylate;

diallyldimethylammonium chloride;

2-acrylamido-2-methyl propane sulfonate;

acrylic acid;

an allylic monomer;

di-allyl phthalate;

di-allyl maleate;

allyl diglycol carbonate;

vinyl formate;

vinyl acetate;

vinyl propionate;

vinyl butyrate;

crotonic acid;

itaconic acid;

vinyl fluoride;

vinyl chloride;

vinylidine fluoride;

tetrafluoroethylene;

acrylamide;

methacrylamide;

methacrylonitrile;

acrolein;

methyl vinyl ether;

ethyl vinyl ether;

vinyl ketone;

ethyl vinyl ketone;

allyl acetate;

allyl propionate;

diethyl maleate;

a diene monomer;

butadiene;

isoprene;

chloroprene;

a derivative thereof; and

a combination thereof.

18. A method of providing fluid loss control in a subterranean application comprising the steps of:

providing degradable crosslinked gelled particles that are formed by a reaction comprising a gelling agent, and a stimuli-degradable cross linking agent that includes at least one degradable group and two unsaturated terminal groups;

introducing the degradable crosslinked gelled particles into a subterranean formation; and

allowing the degradable crosslinked gelled particles to reduce the loss of fluid to a portion of the subterranean formation.