Methods, well cement compositions and lightweight additives therefor

• US 6,648,961 B2
• Filed: 11/20/2002
• Issued: 11/18/2003
• Est. Priority Date: 12/03/2001
• Status: Expired due to Term

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Brothers, Lance E., Keener, Krista L., Braden, James A.
• Primary Examiner(s): MARCANTONI, PAUL D
• Application Number:
  US10/301,029
• Publication Number:
  US 20030101913A1
• Time in Patent Office: 363 Days
• Field of Search: 106/692, 106/705, 106/706, 106/707, 106/709, 106/718, 106/772, 106/803, 106/DIG.1
• US Class Current: 106/692
• CPC Class Codes: C04B 14/104 Bentonite, e.g. montmorillonite
• CPC Class Codes: C04B 18/082 Cenospheres
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: C04B 38/08 by adding porous substances
• CPC Class Codes: C09K 8/42 Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells compositions for plastering C09K8/50
• CPC Class Codes: C09K 8/46 containing inorganic binders, e.g. Portland cement
• CPC Class Codes: C09K 8/473 Density reducing additives, e.g. for obtaining foamed cement compositions
• CPC Class Codes: Y02W 30/91 Use of waste materials as fillers for mortars or concrete
• CPC Class Codes: Y10S 106/01 Fly ash
• CPC Class Codes: Y10S 106/04 Bentonite

Abstract

The present invention provides methods, lightweight well cement compositions and additives for the well cement compositions. The methods of the invention for sealing pipe in a well bore penetrating a zone or formation which readily fractures at low hydrostatic pressure is basically comprised of the steps of providing a lightweight cement composition comprised of a hydraulic cement, water and an additive comprising a suspension of microspheres in water gelled with sodium bentonite, placing the cement composition in the annulus between the pipe and the well bore and allowing the cement composition to set.

Claims

1. A cement composition comprising:

a hydraulic cement;

water; and

an additive comprised of a suspension of fly ash microspheres in water gelled with sodium bentonite.

2. The composition of claim 1 wherein said hydraulic cement is selected from the group consisting of Portland cements, slag cements, pozzolana cements, gypsum cements, aluminous cements and silica cements.

3. The composition of claim 1 wherein said hydraulic cement is Portland cement.

4. The composition of claim 1 wherein said water is selected from the group consisting of fresh water, unsaturated salt solutions and saturated salt solutions.

5. The composition of claim 1 wherein said water is present in an amount in the range of from about 60% to about 250% by weight of hydraulic cement therein.

6. The composition of claim 1 wherein said additive is present in an amount in the range of from about 30% to about 100% by weight of hydraulic cement therein.

7. The composition of claim 1 wherein said microspheres are present in said additive in an amount in the range of from about 30% to about 48% by weight of said additive.

8. The composition of claim 1 wherein said sodium bentonite is present in said additive in an amount in the range of from about 1% to about 2% by weight of said additive.

9. The composition of claim 1 wherein said water is present in said additive in an amount in the range of from about 50% to about 69% by weight of said additive.

10. A lightweight well cement composition comprising:

a hydraulic cement;

water; and

an additive present in an amount in the range of from about 30% to about 100% by weight of hydraulic cement therein, said additive comprising a suspension of fly ash microspheres in water gelled with sodium bentonite.

11. The composition of claim 10 wherein said hydraulic cement is selected from the group consisting of Portland cements, slag cements, pozzolana cements, gypsum cements, aluminous cements and silica cements.

12. The composition of claim 10 wherein said hydraulic cement is Portland cement.

13. The composition of claim 10 wherein said water is selected from the group consisting of fresh water, unsaturated salt solutions and saturated salt solutions.

14. The composition of claim 10 wherein said water is present in an amount in the range of from about 60% to about 250% by weight of hydraulic cement therein.

15. The composition of claim 10 wherein said microspheres are present in said additive in an amount in the range of from about 30% to about 48% by weight of said additive.

16. The composition of claim 10 wherein said sodium bentonite is present in said additive in an amount in the range of from about 1% to about 2% by weight of said additive.

17. The composition of claim 10 wherein said water is present in said additive in an amount in the range of from about 50% to about 69% by weight of said additive.

18. A lightweight well cement composition comprising:

a hydraulic cement selected from the group consisting of Portland cements, slag cements, pozzolana cements, gypsum cements, aluminous cements and silica cements;

water present in an amount in the range of from about 60% to about 250% by weight of hydraulic cement therein and selected from the group consisting of fresh water, unsaturated salt solutions and saturated salt solutions; and

an additive present in an amount in the range of from about 30% to about 100% by weight of hydraulic cement therein, said additive comprising a suspension of fly ash microspheres in water gelled with sodium bentonite.

19. The composition of claim 18 wherein said microspheres are present in additive in an amount in the range of from about 30% to about 48% by weight of said additive.

20. The composition of claim 18 wherein said sodium bentonite is present in said additive in an amount in the range of from about 1% to about 2% by weight of said additive.

21. The composition of claim 18 wherein said water is present in said additive in an amount in the range of from about 50% to about 69% by weight of said additive.