Low density cementitious compositions using limestone
A manufactured cementitious binder includes a hydraulic binder in an amount in the range of from 40 to 75% by weight of the cementitious binder; metakaolin in an amount in the range of from 1 to 30% by weight of the cementitious binder; silica fume in an amount up to 15% by weight of the cementitious binder; limestone in an amount of from 5 to 30% by weight of the cementitious binder, and a cementitious accelerator in a controlled amount of at least 0.5% by weight of the cementitious binder, the cementitious binder providing a cementitious settable composition when added with water, wherein for a density lower than 13 pounds per gallon and of at least 11 pounds per gallon obtained without a lightweight additive, said cementitious settable composition exhibits a 24 hour compressive strength at 100 F, as hardened, of at least 500 psi.
1. A manufactured cementitious binder comprising:
a hydraulic binder in an amount in the range of from 40 to 75% by weight of the cementitious binder;
metakaolin in an amount in the range of from 1 to 30% by weight of the cementitious binder;
silica fume in an amount up to 15% by weight of the cementitious binder;
limestone in an amount of from 5 to 30% by weight of the cementitious binder, and
a cementitious accelerator in a controlled amount of at least 0.5% by weight of the cementitious binder,
the cementitious binder providing a cementitious settable composition when added with water, wherein for a density lower than 13 pounds per gallon and of at least 11 pounds per gallon obtained without a lightweight additive, said cementitious settable composition exhibits a 24 hour compressive strength at 100 F, as hardened, of at least 500 psi.
2. The binder of claim 1 , wherein the settable composition has a 24 hour compressive strength at 100 F, as hardened, of at least 700 psi.
3. The binder of claim 2 , wherein the settable composition has a 24 hour compressive strength at 100 F, as hardened, of at least 800 psi.
4. The binder of claim 1 , wherein the cementitious accelerator is in an amount from 0.6% to 3% by weight of the cementitious binder.
5. The binder of claim 4 , wherein the cementitious accelerator is in an amount from 0.8% to 2.5% by weight of the cementitious binder.
6. The binder of claim 1 , comprising microspheres in an amount less than 15% by weight of the cementitious binder, wherein the cementitious binder provides a cementitious settable composition, when added with water, that has a density lower than 11 pounds per gallon and a 24 hour compressive strength at 100 F, as hardened, of at least 500 psi.
7. The binder of claim 6 , wherein the cementitious settable composition has a density of about 10 pounds per gallon.
8. The binder of claim 6 , wherein the settable composition has a 24 hour compressive strength at 100 F, as hardened, of at least 700 psi.
9. The binder of claim 1 , comprising microspheres in an amount less than 35% by weight of the cementitious binder, wherein the cementitious binder provides a cementitious settable composition, when added with water, that has a density of about 8 pounds per gallon and a 24 hour compressive strength at 100 F, as hardened, of at least 500 psi.
10. The binder of claim 1 , wherein metakaolin is present in the cementitious binder in an amount in the range of from 8 to 25% by weight of the cementitious binder.
11. The binder of claim 1 , wherein a content of calcium carbonate CaCO 3 in the limestone is at least 60% by weight of limestone.
12. The binder of claim 1 , wherein limestone is in an amount of from 10 to 25% by weight of the cementitious binder.
13. A cementitious settable composition comprising:
water; and
a cementitious binder including
a hydraulic binder in an amount in the range of from 40 to 75% by weight of the cementitious binder;
metakaolin in an amount in the range of from 1 to 30% by weight of the cementitious binder;
silica fume in an amount-up to 15% by weight of the cementitious binder;
limestone in an amount of from 5 to 30% by weight of the cementitious binder, and
a cementitious accelerator in a controlled amount of at least 0.5% by weight of the cementitious binder,
wherein, without a lightweight additive, the cementitious settable composition has a density lower than 13 pounds per gallon and of at least 11 pounds per gallon and a 24 hour compressive strength at 100 F, as hardened, of at least 500 psi.
14. The composition of claim 13 , wherein the settable composition has a 24 hour compressive strength at 100 F, as hardened, of at least 700 psi.
15. The composition of claim 14 , wherein the settable composition has a 24 hour compressive strength at 100 F, as hardened, of at least 800 psi.
16. The composition of claim 15 , wherein the cementitious binder comprises microspheres in an amount less than 15% by weight of the cementitious binder, wherein the cementitious settable composition has a density lower than 11 pounds per gallon and a 24 hour compressive strength at 100 F, as hardened, of at least 500 psi.
17. The composition of claim 16 , wherein the settable composition has a density of about 10 pounds per gallon.
18. The composition of claim 17 , wherein the settable composition has a 24 hour compressive strength at 100 F, as hardened, of at least 700 psi.
19. The composition of claim 17 , wherein metakaolin is present in the cementitious binder in an amount in the range of from 8 to 25% by weight of the cementitious binder.
20. The composition of claim 19 , wherein metakaolin is present in the cementitious binder in an amount in the range of from 8 to 18% by weight of the cementitious binder.
21. The composition of claim 13 , wherein limestone is in an amount of from about 10 to 25% by weight of the cementitious binder.
22. A method of cementing comprising:
providing a cementitious settable composition comprising:
water; and
a cementitious binder including
a hydraulic binder in an amount in the range of from 40 to 75% by weight of the cementitious binder;
metakaolin in an amount in the range of from 1 to 30% by weight of the cementitious binder;
silica fume in an amount up to 15% by weight of the cementitious binder;
limestone in an amount of from 5 to 30% by weight of the cementitious binder, and
a cementitious accelerator in a controlled amount of at least 0.5% by weight of the cementitious binder,
wherein, without a lightweight additive, the cementitious settable composition has a density lower than 13 pounds per gallon and of at least 11 pounds per gallon and a 24 hour compressive strength at 100 F, as hardened, of at least 500 psi; and
introducing the cementitious settable composition into an underground formation.
23. The method of claim 22 , wherein the settable composition has a 24 hour compressive strength at 100 F, as hardened, of at least 700 psi.
24. The method of claim 22 , wherein the settable composition has a 24 hour compressive strength at 100 F, as hardened, of at least 800 psi.
25. The method of claim 22 , wherein the cementitious binder comprises microspheres in an amount less than 15% by weight of the cementitious binder, wherein the cementitious binder provides a cementitious settable composition, when added with water, that has a density lower than about 11 pounds per gallon and a 24 hour compressive strength at 100 F, as hardened, of at least 500 psi.
26. The method of claim 22 , wherein the underground formation is a well bore.