Copolymer surfactants for use in downhole fluids

Patent metadata

Field	Value
Publication number	US-10066144-B2
Application number	US-201314387429-A
Country	US
Kind code	B2
Filing date	Nov 8, 2013
Priority date	Nov 8, 2013
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

Various embodiments disclosed relate to hydroxy-terminated poly(alkylene oxide) copolymer surfactants for use downhole, downhole compositions including the same, and methods of using the same. In various embodiments, the present invention provides a method of treating a subterranean formation. The method can include obtaining or providing a composition including a hydroxy-terminated poly(alkylene oxide) copolymer surfactant. The copolymer surfactant can include a first repeating unit having the structure —[R1O]—, wherein at each occurrence R1 is independently a substituted or unsubstituted (C2-C10)alkylene group. The copolymer surfactant can include a second repeating unit having the structure —[R2O]—, wherein at each occurrence R2 is independently a substituted or unsubstituted (C2-C10)alkylene group. The first repeating unit can have a lower molecular weight than the second repeating unit. The first repeating unit and the second repeating unit can have a random copolymer or block copolymer arrangement in the copolymer surfactant. The method can also include placing the composition in a subterranean formation downhole.

First claim

What is claimed is:

1. A method of treating a subterranean formation, the method comprising:
providing a water-based drilling fluid and adding a solid hydroxy-terminated poly(alkylene oxide) copolymer surfactant to the water-based drilling fluid,
wherein the hydroxy-terminated poly(alkylene oxide) copolymer surfactant comprises:
a first repeating unit having the structure —[R 1 O]—, wherein at each occurrence R 1 is an ethylene group; and
a second repeating unit having the structure —[R 2 O]—, wherein at each occurrence R 2 is a propylene group;
wherein the first repeating unit has a lower molecular weight than the second repeating unit, wherein the first repeating unit has a number-average molecular weight of about 5,000 or more, wherein the second repeating unit has a number-average molecular weight of about 2,000 or more, the first repeating unit and the second repeating unit have a random copolymer or block copolymer arrangement in the copolymer surfactant;
wherein the copolymer surfactant has a Davies HLB value of at least about 20 wherein the Davies HLB value is calculated by the following equation:
Davies HLB value=[number of OH groups in the copolymer surfactant]×1.5+[number of oxyethyl units in the copolymer surfactant]×0.33 −[number of oxypropyl units in the copolymer surfactant]×0.15, and

wherein the copolymer surfactant has a number-average molecular weight of about 5,000to about 120,000 and a total weight of the first repeating units is about 10 wt % to about 95 wt % of the copolymer surfactant and;
circulating the water-based drilling fluid through a drilling string, through a drill bit, and back above-surface through an annulus between the drill string and a wellbore.

2. The method of claim 1 , wherein the water-based drilling fluid comprises a bentonite component.

3. The method of claim 1 , wherein the hydroxy-terminated poly(alkylene oxide) copolymer surfactant is about 0.01 wt % to about 20 wt % of the composition.

4. The method of claim 1 , wherein the hydroxy-terminated poly(alkylene oxide) copolymer surfactant is linear.

5. The method of claim 1 , wherein the only repeating units of the hydroxy-terminated poly(alkylene oxide) copolymer surfactant are the first repeating unit and the second repeating unit.

6. The method of claim 1 , wherein the Davies HLB value of the hydroxy-terminated poly(alkylene oxide) copolymer surfactant is about 20 to about 150.

7. The method of claim 1 , wherein the hydroxy-terminated poly(alkylene oxide) copolymer surfactant has the structure:

wherein the repeating units have a random or block copolymer arrangement in the copolymer surfactant;
DP1 is about 150 to about 2600; and
DP2 is about 50 to about 910.

8. The method of claim 1 , wherein the hydroxy-terminated poly(alkylene oxide) copolymer surfactant has the structure:

wherein DP2A′ is about 50 to about 150, DP2A″ is about 0 to about 150, and DP1is about 150 to about 2600, and DP2A′+DP2A″=DP2; and
the first repeating unit and the second repeating units are in a block-copolymer arrangement in the order shown.

9. The method of claim 7 , wherein the hydroxy-terminated poly(alkylene oxide) copolymer surfactant has the structure:

wherein DP1′ is about 100 to about 2600, DP1″ is about 0 to about 2500, and DP1′+DP1″ =DP1; and
the first repeating unit and the second repeating units are in a block-copolymer arrangement in the order shown.

10. A method of treating a subterranean formation, the method comprising:
providing a water-based drilling fluid and adding a solid hydroxy-terminated poly(alkylene oxide) copolymer surfactant to the water-based drilling fluid,
wherein the hydroxy-terminated poly(alkylene oxide) copolymer surfactant comprises:
a first repeating unit and a second repeating unit, wherein the first repeating unit having the structure —[R 1 O]—wherein R 1 is an ethylene group, and the second repeating unit having the structure —[R 2 O]—wherein R 2 is a propylene group, wherein the first repeating unit has a lower molecular weight than the second repeating unit, wherein the first repeating unit has a number-average molecular weight of about 5,000 or more, wherein the second repeating unit has a number-average molecular weight of about 4,000 or more, wherein the first repeating unit and the second repeating unit have a random copolymer or block copolymer arrangement in the copolymer surfactant, wherein the copolymer surfactant has a number-average molecular weight of about 5,000 to about 120,000, and wherein the hydroxy-terminated poly(alkylene oxide) copolymer surfactant has a Davies HLB value of at least about 20, wherein the Davies HLB value is calculated by the following equation:
Davies HLB value=[number of OH groups in the copolymer surfactant]×1.5+[number of oxyethyl units in the copolymer surfactant]×0.33−[number of oxypropyl units in the copolymer surfactant]×0.15, and

circulating the drilling fluid through a drilling string, through a drill bit, and back above-surface through an annulus between the drill string and a wellbore.

11. The method of claim 1 , wherein the first repeating unit has a number-average molecular weight of about 7,000 or more.

12. A method of treating a subterranean formation, the method comprising:
providing a water-based drilling fluid and adding a solid hydroxy-terminated poly(alkylene oxide) copolymer surfactant to the water-based drilling fluid,
wherein the hydroxy-terminated poly(alkylene oxide) copolymer surfactant comprises:
a first repeating unit having the structure —[R 1 O]—, wherein at each occurrence R 1 is an ethylene group: and
a second repeating unit having the structure —[R 2 O]—, wherein at each occurrence R 2 is a propylene group;
wherein the first repeating unit has a lower molecular weight than the second repeating unit, wherein the first repeating unit has a number-average molecular weight of about 3,000 or more, wherein the second repeating unit has a number-average molecular weight of about 4,000or more, the first repeating unit and the second repeating unit have a random copolymer or block copolymer arrangement in the copolymer surfactant;
wherein the copolymer surfactant has a Davies HLB value of at least about 20 wherein the Davies HLB value is calculated by the following equation:
Davies HLB value=[number of OH groups in the copolymer surfactant]×1.5 +[number of oxyethvl units in the copolymer surfactant]×0.33 −[number of oxypropyl units in the copolymer surfactant]×0.15, and

wherein the copolymer surfactant has a number-average molecular weight of about 5,000to about 120,000 and a total weight of the first repeating units is about 10 wt % to about 95 wt % of the copolymer surfactant and;
circulating the water-based drilling fluid through a drilling string, through a drill bit, and back above-surface through an annulus between the drill string and a wellbore.

13. The method of claim 1 , wherein the second repeating unit has a number-average molecular weight of about 6,000 or more.

Assignees

• Halliburton Energy Services Inc

Inventors

• Stone Shantel J
• Collins Ryan Patrick

Classifications

• C09K8/68

  containing organic compounds · CPC title

• C08L71/02

  Polyalkylene oxides · CPC title

• C09K8/12 Primary

  containing synthetic organic macromolecular compounds or their precursors · CPC title

• C09K8/588

  characterised by the use of specific polymers {(polymeric surfactants C09K8/584)} · CPC title

• C09K8/52

  Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning · CPC title