Welan gum in cement compositions

• US 5,004,506 A
• Filed: 04/02/1990
• Issued: 04/02/1991
• Est. Priority Date: 05/07/1987
• Status: Expired due to Term

• Current Assignee: Cp Kelco (JM Huber Corporation)
• Original Assignee: Merck & Co., Inc.
• Inventors: Lindroth, Thomas A., Best, Glen H., Allen, Floyd L.
• Primary Examiner(s): Griffin, Ronald W.
• Assistant Examiner(s): White, Everett
• Application Number:
  US07/502,974
• Time in Patent Office: 365 Days
• Field of Search: 536/114, 536/124, 536/119, 523/130, 166/293, 166/294, 106/720, 106/804, 106/819, 106/823
• US Class Current: 106/729
• CPC Class Codes: C04B 24/38 Polysaccharides or derivatives thereof C04B24/243 takes precedence
• CPC Class Codes: C12P 19/04 Polysaccharides, i.e. compounds containing more than five saccharide radicals attached to each other by glycosidic bonds

Abstract

Cement compositions, i.e., mortar, structured concrete, pre-cast concrete, and oilfield cement, comprising 0.01-0.9% (wt/wt) welan gum are described.

Claims

1. A hydraulic cement composition comprising dry cement and 0.01-0.9% (wt) welan gum, based on the weight of the dry cement, whereby a cement slurry made therefrom is an improved suspension.

2. A cement of claim 1 comprising 0.1-0.5% welan gum.

3. A cement composition of claim 1 wherein the welan gum 5% viscosity ranges from 10,000 cP to about 100 cP is measured at 60 rpm, on an LVT Brookfield viscometer, spindles 4 and 2 respectively, at about 20-25°

C.

4. A cement composition of claim 1, further comprising 0.1 to 1.5% dispersant, based on the weight of the dry cement.

5. A process for controlling water loss from cement slurries which comprises incorporating into said slurries 0.01-0.9% welan gum, based on the weight of the dry cement.

6. A process for controlling water loss from cement slurries according to claim 5 which comprises incorporating into said slurries 0.1-0.5% welan gum, based on the weight of the dry cement.

7. A process for improving the suspension of cement slurries which comprises incorporating into said slurries 0.01-0.9% welan gum, based on the weight of the dry cement.

8. A process of claim 7 wherein the slurry further comprises 0.1 to 1.5% dispersant, based on the weight of the dry cement.

9. A process for improving the suspension of cement slurries according to claim 7 which comprises incorporating into said slurries 0.1-0.5% welan gum, based on the weight of the dry cement.

10. A process of claim 9 wherein the slurry further comprises 0.1 to 1.5% dispersant, based on the weight of the dry cement.