Cement retarder and method of using the same

Patent metadata

Field	Value
Publication number	US-9410072-B2
Application number	US-201113172534-A
Country	US
Kind code	B2
Filing date	Jun 29, 2011
Priority date	Jun 29, 2011
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

The reaction product of a polyhydroxy compound and borax is used as a cement retarder for slurries introduced into a wellbore. The molar ratio of the polyhydroxy compound to boron, derived from the borax, is from 1:1 to about 4:1. The polyhydroxy compound may be a sugar such as a gluconic acid, gluconate or glucoheptonate or a salt thereof.

First claim

What is claimed is:

1. A method of retarding hardening time of a cementitious slurry introduced into a wellbore, comprising:
(a) introducing into the wellbore a cementitious slurry comprising water, a cement and a cement retarder, the cement retarder comprising a borate ester complex formed from a polyhydroxy compound and a borate salt in the presence of caustic, the molar ratio of the polyhydroxy compound to boron in the borate ester complex being between from 1:1 to about 4:1;
(b) disassociating the borate salt and the polyhydroxy compound from the borate ester complex at an elevated temperature to form a disassociated product; and
(c) allowing the slurry to harden to a solid mass.

2. The method of claim 1 , wherein the polyhydroxy compound is a sugar or a salt thereof.

3. The method of claim 2 , wherein the sugar is gluconic acid, gluconate or glucoheptonate or a salt thereof.

4. The method of claim 3 , wherein the sugar is gluconic acid or a salt thereof.

5. The method of claim 4 , wherein the molar ratio of gluconic acid or salt to borate salt in the disassociated product is 2:1.

6. The method of claim 3 , wherein the sugar is a sodium salt of glucoheptonate.

7. The method of claim 6 , wherein the molar ratio of the sodium salt of glucoheptonate to borate salt in the disassociated product is 1:1.

8. The method of claim 6 , wherein the molar ratio of the polyhydroxy compound to boron in the borate ester complex is 4:1.

9. The method of claim 1 , wherein the cement retarder further comprises a lignin sulfonate.

10. The method of claim 9 , wherein the weight ratio of lignin sulfonate to the borate ester complex is about 2:1.

11. The method of claim 9 , wherein the lignin sulfonate is selected from the group consisting of sodium lignosulfonate and calcium lignosulfonate.

12. The method of claim 1 , wherein the borate ester complex contains boron and di-glucoheptonate.

13. The method of claim 1 , wherein the borate salt and the polyhydroxy compound disassociate from the borate ester complex at approximately 290° F.

14. The method of claim 1 , wherein the borate salt is a metaborate.

15. The method of claim 14 , wherein the borate salt is sodium metaborate.

16. The method of claim 1 , wherein hardening of the cementitious slurry into cement is retarded until the temperature is in excess of 350° F.

17. The method of claim 16 , wherein the hardening of the cementitious slurry into cement is retarded until the temperature is in excess of 400° F.

18. The method of claim 1 , wherein the borate salt is sodium tetraborate and further wherein the molar ratio of caustic to sodium tetraborate is from about 1:1 to about 10:1.

19. The method of claim 1 , wherein the Bearden consistency of the cementitious slurry of step (a) is between from about 2 to 20 Bc.

20. The method of claim 19 , wherein the Bearden consistency of the cementitious slurry of step (a) is from about 5 to 11 Bc.

21. A method of cementing a casing within a gas or oil well, comprising:
(a) pumping into a gas or oil well a cementitious slurry comprising water, a hydraulic cement and a cement retarder, the cement retarder comprising a borate ester complex derived from a sugar or a salt thereof and sodium borate as a source of boron, the molar ratio of the sugar or salt thereof to boron in the borate ester complex being from 1:1 to about 4:1, and wherein the cementitious slurry is prepared by forming a first slurry of hydraulic cement and water and then adding the borate ester complex to the first slurry;
(b) disassociating the sodium borate and the sugar or salt thereof from the borate ester complex at a temperature of approximately 270° F. or above; and
(c) cementing the casing with the gas or oil well by allowing the slurry to harden to a solid mass.

22. The method of claim 21 , wherein the borate ester complex is prepared in the presence of caustic.

23. The method of claim 21 , wherein the cement retarder further comprises a lignin sulfonate.

24. The method of claim 23 , wherein the lignin sulfonate is selected from the group consisting of sodium lignosulfonate and calcium lignosulfonate.

25. The method of claim 21 , wherein the borate ester complex is derived from either (a) boron and a di-gluconate, (b) boron and a mono-glucoheptonate, (c) boron and a di-glucoheptonate or (d) boron and a mono-gluconate.

26. The method of claim 21 , wherein the sugar is gluconic acid, gluconate or glucoheptonate or a salt thereof.

27. The method of claim 26 , wherein the sugar is a sodium salt of glucoheptonate and further wherein the molar ratio of the sodium salt of glucoheptonate to boron in the borate ester complex is 1:1.

28. A method of preventing over-retarding of a cementitious slurry during cementing within a gas or oil well, comprising:
(a) pumping into a gas or oil well a cementitious slurry comprising water, a hydraulic cement and a cement retarder, the cement retarder comprising a borate ester complex of either (a) boron and a di-gluconate, boron and a mono-glucoheptonate, boron and a di-glucoheptonate or boron and a mono-gluconate, and wherein the cementitious slurry is prepared by forming a first slurry of hydraulic cement and water and then adding the borate ester complex to the first slurry;
(b) disassociating a borate salt from the borate ester complex at temperatures of 270° F. and above and then releasing the borate salt into the cementitious slurry
wherein over-retarding of the cementitious slurry is prevented by disassociation of the borate salt from the borate ester complex.

29. The method of claim 28 , wherein the borate ester complex is prepared in the presence of caustic.

30. The method of claim 28 , wherein the cement retarder further comprises a lignin sulfonate.

31. The method of claim 28 , wherein the borate salt is a metaborate salt.

32. The method of claim 28 , wherein the Bearden consistency of the cementitious slurry of step (a) is from about 5 to 11 Bc.

Assignees

• Scoggins William Chrys
• Baker Hughes Inc

Inventors

• Scoggins William Chrys

Classifications

• E21B33/13

  Methods or devices for cementing, for plugging holes, crevices or the like · CPC title

• C04B28/02

  containing hydraulic cements other than calcium sulfates · CPC title

• C09K8/467 Primary

  containing additives for specific purposes · CPC title

• C07F5/022

  without C-boron linkages · CPC title

• C04B2103/20

  Retarders · CPC title