Kinetic hydrate inhibitors with pendent amino functionality

Patent metadata

Field	Value
Publication number	US-9840654-B2
Application number	US-201213679457-A
Country	US
Kind code	B2
Filing date	Nov 16, 2012
Priority date	Nov 16, 2012
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

A kinetic gas hydrate inhibitor is provided as a polyester polymer with a plurality of amino or ammonium groups pendent directly from the backbone. A composition containing concentrated kinetic inhibitor is injected into gas wells, or into other systems involving transporting liquid gas mixtures through a conduit. Use of the kinetic inhibitor prevents formation of gas hydrates under conditions of temperature and pressure where they would otherwise occur.

First claim

What is claimed is:

1. A method for inhibiting gas hydrate formation in an aqueous phase that is in contact with a gaseous or liquid organic phase, the method comprising:
preparing a composition comprising 10-50% by weight of a kinetic inhibitor, and
injecting the composition into the aqueous phase to provide the aqueous phase with 0.01-3% by weight of the kinetic inhibitor,
wherein the kinetic inhibitor is a polyester polymer comprising a polyester backbone chain and a plurality of pendent amino groups that are directly attached to the polyester backbone chain, and
wherein the polyester polymer is produced by polymerizing a plurality of acid monomers with a plurality of polyols, each of the acid monomers comprising the pendent amino group.

2. The method according to claim 1 , wherein the aqueous phase comprises 0.01-2 weight % of the kinetic inhibitor.

3. The method according to claim 1 , wherein the inhibitor is made by polymerizing an amino functional diacid, diester, or mixed acid ester with an alkylene or oxyalkylene diol or triol.

4. The method according to claim 1 , wherein the inhibitor is made by polymerizing a diacid, diester, or mixed acid ester with an amine functional diol or triol.

5. The method according to claim 1 , wherein the acid monomers have the following structure

and the polyols have the following structure
B(OH) n

wherein X is amino, A is alkylene of 1 to 40 carbon atoms, R 1 and R 2 are independently —H or alkyl, B is selected from branched or unbranched alkylene and branched or unbranched oxa-substituted alkylene, and n is 2, 3, or 4.

6. The method according to claim 5 wherein A is C 2 -C 6 alkylene, B is C 2 -C 12 alkylene or polyoxyalkylene, and n is 2 or 3.

7. The method according to claim 5 , wherein A is C 3 alkylene or C 4 alkylene and the polyol component is ethylene glycol, diethylene glycol, or triethylene glycol.

8. The method according to claim 5 , wherein the acid monomers are selected from the group consisting of aspartic acid, glutamic acid, protected aspartic acid, and protected glutamic acid.

9. The method according to claim 8 , wherein the polyols are selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol.

10. The method according to claim 1 , further comprising providing the aqueous phase with a synergist made of C 3 to C 10 ethers of C 2 to C 4 glycols.

11. The method according to claim 10 , wherein the synergist is C 3 to C 6 ethers of C 2 to C 3 glycols.

12. The method according to claim 10 , wherein the synergist is selected from the group consisting of 2-butoxyethanol, 2-isopropoxyethanol, 1-propoxy-2-propanol, 2-(2-butoxyethoxy)ethanol, 1-butoxy-2-propanol, and 2-propoxyethanol.

13. The method according to claim 1 , wherein a solution of the kinetic inhibitor is greater than 20% biodegradable, exhibits no inherent cloud point behavior upon heating, and gives an induction time greater than 24hours at 6° C. subcooling using synthetic natural gas.

Assignees

• M-I L L C
• Schlumberger Norge As

Inventors

• Cole Rachel Anne
• Grinrod Anders
• Cely Alexandra

Classifications

• C09K2208/22

  Hydrates inhibition by using well treatment fluids containing inhibitors of hydrate formers · CPC title

• C09K8/528 Primary

  inorganic depositions, e.g. sulfates or carbonates · CPC title

• C09K8/52 Primary

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