Claims
- 1. A method of cementing within a wellbore, comprising:
introducing a cement slurry comprising a hydraulic cement base and a natural mineral fiber into said wellbore; and allowing said cement slurry to cure within said wellbore to form a hardened cement composition within said wellbore; wherein a temperature of at least a first portion of said well bore is greater than about 180° F.; wherein said natural mineral fiber is present in said cement slurry in an amount greater than about 10% by weight of cement, and is also present in said cement slurry in an amount selected to be effective to result in at least a portion of said cured cement composition having a ratio of flexural strength to compressive strength that is greater than or equal to about 0.35 at said temperature of said at least a first portion of said well bore that is greater than about 180° F.; and wherein said natural mineral fiber comprises at least one calcium silicate natural mineral fiber.
- 2. The method of claim 1, wherein said calcium silicate natural mineral fiber comprises at least one of wollastonite, pyrophillite, algamatolite, or a mixture thereof.
- 3. The method of claim 1, wherein a temperature of said at least a first portion of said well bore is greater than about 200° F.; and wherein said natural mineral fiber is present in said cement slurry in an amount selected to be effective to result in at least a portion of said cured cement composition having a ratio of flexural strength to compressive strength that is greater than or equal to about 0.35 at said temperature of said at least a first portion of said wellbore that is greater than about 200° F.
- 4. The method of claim 1, wherein a temperature of said at least a first portion of said well bore is greater than about 240° F.; and wherein said natural mineral fiber is present in said cement slurry in an amount selected to be effective to result in at least a portion of said cured cement composition having a ratio of flexural strength to compressive strength that is greater than or equal to about 0.35 at said temperature of said at least a first portion of said wellbore that is greater than about 240° F.
- 5. The method of claim 1, wherein a temperature of said at least a first portion of said well bore is greater than about 380° F.; and wherein said natural mineral fiber is present in said cement slurry in an amount selected to be effective to result in at least a portion of said cured cement composition having a ratio of flexural strength to compressive strength that is greater than or equal to about 0.5 at said temperature of said at least a first portion of said wellbore that is greater than about 380° F.
- 6. The method of claim 1, wherein said natural mineral fiber is present in said cement slurry in an amount selected to be effective to result in at least a portion of said cured cement composition having a ratio of flexural strength to compressive strength that is greater than or equal to about 50% higher than the ratio of flexural strength to compressive strength of a cured conventional cement composition having substantially the same composition, but without said natural mineral fiber component, at said temperature of said at least a first portion of said wellbore that is greater than about 180° F.
- 7. The method of claim 1, wherein a temperature of said at least a first portion of said well bore is less than about 180° F. when said cement slurry is introduced into said wellbore and allowed to cure; and further comprising allowing the temperature of said at least a first portion of said wellbore to rise above about 180° F.; wherein said natural mineral fiber is present in said cement slurry in an amount selected to be effective to result in an increase in the compressive strength of at least a portion of said cured cement composition when said temperature of said at least a first portion of said wellbore is allowed to rise above about 180° F.
- 8. The method of claim 1, wherein said natural mineral fiber is present in said cement slurry in an amount of from greater than about 10% by weight of cement to about 150% by weight of cement.
- 9. The method of claim 1, wherein said well bore is a geothermal well or a steam injection well.
- 10. The method of claim 1, wherein said hydraulic cement base comprises Portland Cement.
- 11. A method of cementing within a wellbore, comprising:
introducing a cement slurry comprising a hydraulic cement base and wollastonite into said wellbore; and allowing said cement slurry to cure within said wellbore to form a hardened cement composition within said wellbore; wherein a temperature of at least a first portion of said well bore is greater than about 180° F.; wherein said wollastonite is present in said cement slurry in an amount greater than about 10% by weight of cement, and is also present in said cement slurry in an amount selected to be effective to result in at least a portion of said cured cement composition having a ratio of flexural strength to compressive strength that is greater than or equal to about 0.35 at said temperature of said at least a first portion of said well bore that is greater than about 180° F.
- 12. The method of claim 11, wherein said hydraulic cement base comprises Portland Cement.
- 13. The method of claim 12, wherein a temperature of said at least a portion of said well bore is greater than about 200° F.; and wherein said wollastonite is present in said cement slurry in an amount selected to be effective to result in at least a portion of said cured cement composition having a ratio of flexural strength to compressive strength that is greater than or equal to about 0.35 at said temperature of said at least a first portion of said wellbore that is greater than about 200° F.
- 14. The method of claim 12, wherein a temperature of said at least a portion of said well bore is greater than about 240° F.; and wherein said wollastonite is present in said cement slurry in an amount selected to be effective to result in at least a portion of said cured cement composition having a ratio of flexural strength to compressive strength that is greater than or equal to about 0.35 at said temperature of said at least a first portion of said wellbore that is greater than about 240° F.
- 15. The method of claim 12, wherein a temperature of said at least a first portion of said well bore is greater than about 380° F.; and wherein said wollastonite is present in said cement slurry in an amount selected to be effective to result in at least a portion of said cured cement composition having a ratio of flexural strength to compressive strength that is greater than or equal to about 0.5 at said temperature of said at least a first portion of said wellbore that is greater than about 380° F.
- 16. The method of claim 12, wherein said wollastonite is present in said cement slurry in an amount selected to be effective to result in at least a portion of said cured cement composition having a ratio of flexural strength to compressive strength that is greater than or equal to about 50% higher than the ratio of flexural strength to compressive strength of a cured conventional cement composition having substantially the same composition, but without said wollastonite component, at said temperature of said at least a first portion of said wellbore that is greater than about 180° F.
- 17. The method of claim 12, wherein a temperature of said at least a first portion of said well bore is less than about 180° F. when said cement slurry is introduced into said wellbore and allowed to cure; and further comprising allowing the temperature of said at least a first portion of said wellbore to rise above about 180° F.; wherein said wollastonite is present in said cement slurry in an amount selected to be effective to result in an increase in the compressive strength of at least a portion of said cured cement composition when said temperature of said at least a first portion of said wellbore is allowed to rise above about 180° F.
- 18. The method of claim 12, wherein said wollastonite is present in said cement slurry in an amount of from greater than about 10% by weight of cement to about 150% by weight of cement.
- 19. The method of claim 12, wherein said well bore is a geothermal well or a steam injection well.
- 20. A fiber-containing cement composition, comprising a hydraulic cement base and a natural mineral fiber; wherein said natural mineral fiber is present in an amount greater than about 10% by weight of cement; wherein said natural mineral fiber is also present in said fiber-containing cement composition in an amount selected to be effective so as to result in a cement slurry and a cured cement composition formed from said cement slurry having a ratio of flexural strength to compressive strength that is greater than or equal to about 0.35 when said cement slurry is exposed to a temperature of greater than about 180° F.; and wherein said natural mineral fiber comprises at least one calcium silicate natural mineral fiber.
- 21. The fiber-containing cement composition of claim 20, wherein said calcium silicate natural mineral fiber comprises at least one of wollastonite, pyrophillite, algamatolite, or a mixture thereof.
- 22. The fiber-containing cement composition of claim 20, wherein said calcium silicate natural mineral fiber comprises wollastonite.
- 23. The fiber-containing cement composition of claim 22, wherein said hydraulic cement base comprises Portland Cement.
Parent Case Info
[0001] This application claims priority on co-pending U.S. provisional patent application serial No. 60/269,153 filed on Feb. 15, 2001, the disclosure of which is incorporated herein by reference in its entirety.
Provisional Applications (1)
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Number |
Date |
Country |
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60269153 |
Feb 2001 |
US |