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US 6,019,835 AGranted
Cement compositions and biodegradable dispersants therefor
AssigneesHalliburton Energy Services, Inc., LignoTech USA, Inc.
InventorsJiten Chatterji, D. Chad Brenneis, Dennis W. Gray, Stuart E. Lebo, Stephen L. Dickman
Life of this patent
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Abstract
This invention provides improved cement composition and biodegradable dispersants therefor. The biodegradable dispersants are basically comprised of a high molecular weight, phenolic hydroxy group blocked, alkali metal lignosulfonate.
Claims19
A cement composition comprising:
- a hydraulic cement;
- sufficient water to form a pumpable slurry;
- and
- a biodegradable dispersant comprised of a phenolic hydroxyl group blocked alkali metal lignosulfonate having a molecular weight in the range of from about 60,000 to about 120,000 daltons present in said composition in an amount effective to reduce the apparent viscosity of said cement composition.
1 more element
A cement composition comprising:
- a hydraulic cement;
- water present in an amount of about 38% by weight of cement in said composition;
- and
- a biodegradable dispersant comprised of a phenolic hydroxyl group blocked sodium lignosulfonate having a molecular weight of about 80,000 daltons present in an amount of about 0.75% by weight of cement in said composition.
1 more element
A method of preparing a biodegradable cement composition which has reduced viscosity prior to when the cement composition gels and sets comprising the steps of:
- preparing a cement composition comprised of a hydraulic cement and sufficient water to form a pumpable slurry;
- and
- combining a biodegradable dispersant with said cement composition in an amount effective to reduce the viscosity thereof comprised of a phenolic hydroxyl group blocked alkali metal lignosulfonate having a molecular weight in the range of from about 60,000 to about 120,000 daltons and having a phenolic hydroxyl group content in the range of from about 0.01% to about 0.1% by weight of said dispersant.
Dependencies are inferred from the claim text.