Calcium aluminate cement composition containing a set retarder of an organic acid and a polymeric mixture
A cement composition for use in an oil or gas well, the cement composition comprises: a calcium aluminate cement; water; an organic acid; and a polymeric mixture comprising: (A) water; (B) citric acid; (C) a first polymer, wherein the first polymer: (i) comprises a cellulose backbone and carboxymethyl functional groups; and (ii) has a molecular weight of less than 100,000; and (D) a second polymer, wherein the second polymer: (i) comprises a lignosulfonate; and (ii) has a molecular weight of less than 100,000, wherein a test composition consisting essentially of: the cement; the water; the organic acid; and the polymeric mixture, and in the same proportions as in the cement composition has a thickening time of at least 5 hours at a temperature of 300° F. (148.9° C.) and a pressure of 10,000 psi (68.9 MPa).
1. A method of cementing in a subterranean formation comprising:
introducing a cement composition into the subterranean formation, wherein the cement composition comprises:
(A) a calcium aluminate cement;
(B) water;
(C) an organic acid; and
(D) a polymeric mixture comprising:
(i) water;
(ii) citric acid;
(iii) a first polymer, wherein the first polymer:
(a) comprises a cellulose backbone and carboxymethyl functional groups; and
(b) has a molecular weight of less than 100,000; and
(iv) a second polymer, wherein the second polymer:
(a) comprises a lignosulfonate; and
(b) has a molecular weight of less than 100,000,
wherein a test composition consisting essentially of: the cement; the water; the organic acid; and the polymeric mixture, and in the same proportions as in the cement composition has a thickening time of at least 5 hours at a temperature of 300° F. (148.9° C.) and a pressure of 10,000 psi (68.9 MPa); and
allowing the cement composition to set.
2. The method according to claim 1 , wherein the water is selected from the group consisting of freshwater, brackish water, and saltwater, in any combination thereof in any proportion.
3. The method according to claim 1 , wherein the organic acid is selected from the group consisting of citric acid, tartaric acid, lactic acid, ascorbic acid, and combinations thereof.
4. The method according to claim 1 , wherein the first polymer, the second polymer, or the first and the second polymers have a molecular weight of less than about 30,000.
5. The method according to claim 1 , wherein the first polymer, the second polymer, or the first and the second polymers have a molecular weight of less than about 25,000.
6. The method according to claim 1 , wherein the organic acid and the polymeric mixture are in at least a sufficient concentration such that the test composition has a thickening time of at least 5 hours at at least one temperature in the range of about 300° F. to about 370° F. (about 148.9° C. to about 187.8° C.) and a pressure of 10,000 psi (68.9 MPa).
7. The method according to claim 1 , wherein the cement composition has a thickening time of at least 5 hours at a temperature of 300° F. (148.9° C.) and a pressure of 10,000 psi (68.9 MPa).
8. The method according to claim 7 , wherein the organic acid and the polymeric mixture are in at least a sufficient concentration such that the cement composition has a thickening time in the range of about 5 to about 15 hours at at least one temperature in the range of about 300° F. to about 370° F. (about 148.9° C. to about 187.8° C.) and a pressure of 10,000 psi (68.9 MPa).
9. The method according to claim 1 , wherein the organic acid and the polymeric mixture are in a concentration equal to or less than a sufficient concentration such that the cement composition has a setting time of less than 48 hours at a temperature of 300° F. (148.9° C.).
10. The method according to claim 1 , wherein the organic acid is in a concentration in the range of about 0.2% to about 4% by weight of the cement.
11. The method according to claim 1 , wherein the polymeric mixture is in a concentration in the range of about 0.05% to about 10% by weight of the cement.
12. The method according to claim 1 , wherein the cement composition further comprises other additives.
13. The method according to claim 12 , wherein the other additives are selected from the group consisting of a filler, a fluid loss additive, a friction reducer, a light-weight additive, a defoaming agent, a high-density additive, a mechanical property enhancing additive, a lost-circulation material, a filtration-control additive, a thixotropic additive, and combinations thereof.
14. The method according to claim 1 , wherein the cement composition has a density in the range of about 9 to about 22 ppg.
15. The method according to claim 1 , wherein the subterranean formation has a bottomhole temperature in the range of about 200° F. to about 370° F. (about 93.3° C. to about 187.8° C.).
16. The method according to claim 15 , wherein the organic acid and the polymeric mixture are in at least a sufficient concentration such that the cement composition has a thickening time in the range of about 5 to about 15 hours, at the bottomhole temperature and pressure of the well.
17. The method according to claim 1 , wherein the subterranean formation is penetrated by a well.
18. The method according to claim 17 , wherein the well is a high-temperature well, a high-pressure well, a geothermal well, a sour gas well, or an acid gas well.
19. The method according to claim 1 , further comprising at least one of the following steps: perforating, fracturing, or performing an acidizing treatment, wherein the step is performed after the step of allowing.