Claims
- 1. An improved environmentally acceptable well cement fluid loss control additive comprising hydroxyethylcellulose having a reduced molecular weight in the range of from about 30,000 to about 90,000 and being ethoxylated in an amount in the range of from about 1 to about 4 moles of ethylene oxide per anhydroglucose unit.
- 2. The additive of claim 1 wherein said hydroxyethylcellulose has an average molecular weight of about 60,000.
- 3. The additive of claim 1 wherein said hydroxyethylcellulose is ethoxylated in the range of from about 2.2 to about 2.7 moles of ethylene oxide per anhydroglucose unit.
- 4. The additive of claim 1 wherein said hydroxyethylcellulose is ethoxylated in an average amount of about 2.5 moles of ethylene oxide per anhydroglucose unit.
- 5. The additive of claim 1 wherein the additive is stable and effectively controls fluid loss from cement compositions at temperatures above 230° F. to at least about 260° F.
- 6. The additive of claim 1 wherein the additive can be utilized in contact with salt water containing salt up to 37.2% by weight without losing effectiveness.
- 7. The additive of claim 1 wherein the additive can be dissolved in water up to about 12.5% by weight of the resulting solution.
- 8. The additive of claim 1 further comprising a temperature stability increasing agent.
- 9. The additive of claim 8 wherein said temperature stability increasing agent is selected from the group consisting of synthetic hectorite, magnesium oxide and sodium thiosulfate.
- 10. The additive of claim 8 wherein said temperature stability increasing agent is magnesium oxide.
- 11. The additive of claim 8 wherein said temperature stability increasing agent is present in said additive in an amount in the range of from about 50% to about 500% by weight of said ethoxylated hydroxyethylcellulose.
- 12. The additive of claim 8 wherein said temperature stability increasing agent is present in an amount of about 100% by weight of said ethoxylated hydroxyethylcellulose.
- 13. An improved environmentally acceptable well cement fluid loss control additive comprising:
hydroxyethylcellulose having a reduced molecular weight in the range of from about 30,000 to about 90,000 and being ethoxylated in an amount in the range of from about 1 to about 4 moles of ethylene oxide per anhydroglucose unit; and a temperature stability increasing agent present in said additive in an amount in the range of from about 50% to about 500% by weight of said ethoxylated hydroxyethylcellulose and selected from the group consisting of synthetic hectorite, magnesium oxide and sodium thiosulfate.
- 14. The additive of claim 13 wherein said hydroxyethylcellulose has an average molecular weight of about 60,000.
- 15. The additive of claim 13 wherein said hydroxyethylcellulose is ethoxylated in the range of from about 2.2 to about 2.7 moles of ethylene oxide per anhydroglucose unit.
- 16. The additive of claim 13 wherein said hydroxyethylcellulose is ethoxylated in an average amount of about 2.5 moles of ethylene oxide per anhydroglucose unit.
- 17. The additive of claim 13 wherein the additive is stable and effectively controls fluid loss from cement compositions at temperatures above 230° F. to at least about 260° F.
- 18. The additive of claim 13 wherein the additive can be utilized in contact with salt water containing salt up to 37.2% by weight without losing effectiveness.
- 19. The additive of claim 13 wherein the additive can be dissolved in water up to about 12.5% by weight of the resulting solution.
- 20. The additive of claim 13 wherein said temperature stability increasing agent is magnesium oxide.
- 21. The additive of claim 13 wherein said temperature stability increasing agent is present in an amount of about 100% by weight of said ethoxylated hydroxyethylcellulose.
- 22. An improved environmentally acceptable well cement fluid loss control additive comprising:
hydroxyethylcellulose having a reduced molecular weight of about 60,000 and being ethoxylated in an amount in the range of from about 2.5 moles of ethylene oxide per anhydroglucose unit; and a temperature stability increasing agent present in said additive in an amount of about 100% by weight of said ethoxylated hydroxyethylcellulose and wherein said temperature stability increasing agent is magnesium oxide.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a divisional of application Ser. No. 09/732,861 filed on Dec. 8, 2000, now pending.
Divisions (1)
|
Number |
Date |
Country |
Parent |
09732861 |
Dec 2000 |
US |
Child |
10135492 |
Apr 2002 |
US |