Storable cementitious slurries containing boric acid and method of using the same

• US 20050022992A1
• Filed: 07/30/2003
• Published: 02/03/2005
• Est. Priority Date: 07/30/2003
• Status: Active Grant

• Current Assignee: Baker Hughes, a GE Company, LLC (Baker Hughes Company)
• Original Assignee: BJ Services Company
• Inventors: Di Lullo Arias, Gino F., Rae, Philip James
• Granted Patent: US 6,907,928 B2
• Time in Patent Office: Days
• US Class Current: 166/285
• CPC Class Codes: C04B 14/045 Alkali-metal containing silicates, e.g. petalite waterglass C04B12/04
• CPC Class Codes: C04B 2103/408 Dispersants
• CPC Class Codes: C04B 22/0013 Boron compounds
• CPC Class Codes: C04B 22/10 containing carbon in the anion
• CPC Class Codes: C04B 22/12 containing halogen in the anion
• CPC Class Codes: C04B 22/16 containing phosphorus in the anion, e.g. phosphates
• CPC Class Codes: C04B 24/122 Hydroxy amines
• CPC Class Codes: C04B 24/2664 of ethylenically unsaturated dicarboxylic acid polymers, e.g. maleic anhydride copolymers
• CPC Class Codes: C04B 24/34 Natural resins, e.g. rosin C04B24/243 takes precedence
• CPC Class Codes: C04B 28/04 Portland cements
• CPC Class Codes: C04B 40/0658 Retarder inhibited mortars activated by the addition of accelerators or retarder-neutralising agents
• CPC Class Codes: C09K 8/467 containing additives for specific purposes

Abstract

A storable, hydraulically-active, cementitious slurry is made and used to cement within subterranean foundations for oil and gas wells. The slurry is made from a hydraulically-active cementitious material, a suspending agent, and, as a retarder, boric acid. The boric acid is present in the cementitious slurry in an amount sufficient to lower the pH of the storable cementitious slurry to at least 12.0, preferably to at least 11.0 or preferably, for reasons of longevity, to a pH of at least 9.0. Generally the amount of boric acid in the cementitious slurry is between from about 1 to about 6 percent by weight. Preferred as suspending agent are iota carrageenan as well as poly (methyl vinyl ether/maleic anhydride) decadiene copolymer. The slurry remains liquid during storage. The slurry is activated when needed for cementing and is pumped into the subterranean formation where it is allowed to set.

Claims

1. A storable, hydraulically-active, cementitious slurry comprising:

a hydraulically-active cementitious material suitable for cementing within subterranean formations for oil or gas wells;

a suspending agent; and

boric acid

wherein the amount of boric acid in the cementitious slurry is between from about 1 to about 6 percent by weight.

2. The storable, hydraulically-active, cementitious slurry of claim 1, wherein the suspending agent is iota carrageenan.

3. The storable, hydraulically-active, cementitious slurry of claim 1, wherein the suspending agent comprises poly (methyl vinyl ether/maleic anhydride) decadiene copolymer.

4. The storable, hydraulically-active, cementitious slurry of claim 1, wherein the hydraulically-active cementitious material is Portland cement.

5. The storable, hydraulically-active, cementitious slurry of claim 1, which further comprises a dispersing agent.

6. A storable, hydraulically-active, cementitious slurry comprising:

a hydraulically-active cementitious material suitable for cementing within subterranean formations for oil or gas wells;

a suspending agent; and

boric acid

wherein the amount of boric acid in the cementitious slurry is sufficient to lower the pH of the storable cementitious slurry to at least 12.0.

7. The storable, hydraulically-active, cementitious slurry of claim 6, wherein the amount of boric acid in the cementitious slurry is sufficient to lower the pH of the storable cementitious slurry to at least 11.0.

8. The storable, hydraulically-active, cementitious slurry of claim 7, wherein the slurry contains boric acid in an amount sufficient to lower the pH to at least 10.0.

9. The storable, hydraulically-active, cementitious slurry of claim 8, wherein the slurry contains boric acid in an amount sufficient to lower the pH to at least 9.0.

10. The storable, hydraulically-active, cementitious slurry of claim 9, wherein the slurry contains boric acid in an amount sufficient to lower the pH to at least 8.0.

11. The storable, hydraulically-active, cementitious slurry of claim 10, wherein the slurry contains boric acid in an amount sufficient to lower the pH to at least 7.0.

12. The storable, hydraulically-active, cementitious slurry of claim 10, wherein the slurry contains boric acid in an amount sufficient to lower the pH to at least 6.0.

13. The storable, hydraulically-active, cementitious slurry of claim 7, wherein the suspending agent is iota carrageenan.

14. The storable, hydraulically-active, cementitious slurry of claim 7, wherein the suspending agent comprises poly (methyl vinyl ether/maleic anhydride) decadiene copolymer.

15. The storable, hydraulically-active, cementitious slurry of claim 6, wherein the hydraulically-active cementitious material is Portland cement.

16. The storable, hydraulically-active, cementitious slurry of claim 7, which further comprises a dispersing agent.

17. A method of cementing within a subterranean formation for an oil or gas well, the method comprising the steps of:

formulating a storable, hydraulically-active, cementitious slurry by mixing together a hydraulically-active cementitious material of a type suitable for cementing within subterranean formations for oil or gas wells, a suspending agent and boric acid, wherein the pH of the cementitious slurry is between from about 6.0 to about 12.0;

storing the storable slurry until required for cementing;

activating the storable slurry;

pumping the activated slurry into the subterranean formation; and

allowing the activated slurry to set.

18. The method of claim 17, wherein the pH of the cementitious slurry is between from about 6.0 to about 11.0.

19. The method of claim 18, wherein the pH of the cementitious slurry is between from about 7.0 to about 10.0.

20. The method of claim 18, wherein the suspending agent is iota carrageenan.

21. The method of claim 18, wherein the suspending agent comprises poly (methyl vinyl ether/maleic anhydride) decadiene copolymer.

22. The method of claim 17, wherein the hydraulically-active cementitious material is Portland cement.

23. The method of claim 18, which further comprises a dispersing agent.

24. A method of cementing within a subterranean formation for an oil or gas well, the method comprising the steps of:

formulating a storable, hydraulically-active, cementitious slurry by mixing together a hydraulically-active cementitious material of a type suitable for cementing within subterranean formations for oil or gas wells, a suspending agent and boric acid, wherein the amount of boric acid in the cementitious slurry is between from about 1.0 to about 6.0 weight percent of the cementitious slurry;

storing the storable slurry until required for cementing;

activating the storable slurry;

pumping the activated slurry into the subterranean formation; and

allowing the activated slurry to set.

25. The method of claim 24, wherein the storable slurry contains boric acid in an amount sufficient to lower the pH to at least 11.0.

26. The method of claim 25, wherein the storable slurry contains boric acid in an amount sufficient to lower the pH to at least 10.0.

27. The method of claim 26, wherein the slurry contains boric acid in an amount sufficient to lower the pH to at least 9.0.

28. The method of claim 27, wherein the storable slurry contains boric acid in an amount sufficient to lower the pH to at least 8.0.

29. The method of claim 28, wherein the slurry contains boric acid in an amount sufficient to lower the pH to at least 7.0.

30. The method of claim 29, wherein the slurry contains boric acid in an amount sufficient to lower the pH to at least 6.0.

31. The method of claim 25, wherein the suspending agent is iota carrageenan.

32. The method of claim 25, wherein the slurry is activated by adding thereto an activator.

33. The method of claim 32, wherein the activator is an alkali halide, ammonium halide, KF, dibasic alkali phosphate, tribasic alkali phosphate, ammonium fluoride, tribasic ammonium phosphate, dibasic ammonium phosphate, ammonium bifluoride, sodium fluoride, a triethanolamine, an alkali silicate or an alkali carbonate.

34. The method of claim 33, wherein the activator is KF, dibasic potassium phosphate, tribasic potassium phosphate, ammonium fluoride, ammonium bifluoride, tribasic ammonium phosphate, dibasic ammonium phosphate, sodium fluoride, a triethanolamine, an alkali silicate or an alkali carbonate.

35. The method of claim 24, wherein the suspending agent comprises poly (methyl vinyl ether/maleic anhydride) decadiene copolymer.

36. The method of claim 24, wherein the hydraulically-active cementitious material is Portland cement

37. The method of claim 24, wherein the storable slurry further comprises a dispersing agent.

38. A method of cementing within a subterranean formation for an oil or gas well, the method comprising the steps of:

formulating a storable, hydraulically-active, cementitious material by mixing together Portland cement, a suspending agent and boric acid wherein the amount of boric acid in the cementitious material is between from about 1.0 to about 6.0 weight percent;

storing the storable slurry, until required for cementing, at a pH between from about 6.0 to about 12.0;

activating the storable slurry;

pumping the activated slurry into the subterranean formation; and

allowing the activated slurry to set.

39. The method of claim 38, wherein the pH of the storable slurry is between from about 6.0 to about 11.0.