PUMICE CONTAINING COMPOSITIONS FOR CEMENTING A WELL

• US 20090105099A1
• Filed: 10/22/2008
• Published: 04/23/2009
• Est. Priority Date: 10/22/2007
• Status: Active Grant

• Current Assignee: Sanjel Energy Services Incorporated
• Original Assignee: Sanjel Limited Partnership
• Inventors: WARRENDER, Neil, HUYNH, Nga Tu, MAHMOUDKHANI, Amir, SYLVESTRE, Charles
• Granted Patent: US 7,867,954 B2
• Time in Patent Office: Days
• US Class Current: 507/269
• CPC Class Codes: C04B 14/16 porous, e.g. pumice
• CPC Class Codes: C04B 18/08 Flue dust , i.e. fly ash
• CPC Class Codes: C04B 2103/0088 Compounds chosen for their latent hydraulic characteristics, e.g. pozzuolanes
• CPC Class Codes: C04B 28/04 Portland cements
• CPC Class Codes: C09K 8/467 containing additives for specific purposes
• CPC Class Codes: Y02W 30/91 Use of waste materials as fillers for mortars or concrete

Abstract

A cement composition comprises fine pumice particles, for use in cementing subterranean wells, and oil and gas wells in particular. The pumice containing cement blends feature enhanced compressive strength, and favourable compressive strength to Young'"'"'s Modulus ratios. Lightweight cement blends containing pumice, and their use in cementing oil and gas wells are also described.

Claims

1. A cement composition for use in the manufacture of a subterranean well, the cement composition comprising:

(a) about 5-100% (wt) of an amorphous reactive pozzolan; and

(b) about 0-95% (wt) of a mixture of API Portland cement and Fly ash in a ratio of about 100;

0 to about 50;

50.

2. The cement of claim 1 wherein the amorphous reactive pozzolan comprises pumice.

3. The cement of claim 1 or 2 wherein the API Portland cement comprises Class A cement.

4. The cement of claim 1 or 2 wherein the API Portland cement comprises Class G cement.

5. The cement of claim 2 wherein the cement has a compressive strength to Young'"'"'s Modulus ratio of greater than about 5.0×

10<sup>−

3</sup>, with a compressive strength of greater than about 3.5 MPa.

6. The cement of claim 2 wherein the cement has a density of less than about 1400 kg/m³.

7. The cement of claim 6 wherein the cement has a density of less than about 1300 kg/m³.

8. The cement of claim 7 wherein the cement has a density of less than about 1200 kg/m³.

9. The cement of claim 8 wherein the cement has a density of less than about 1100 kg/m³.

10. The cement of claim 2 wherein the cement has a transition time of less than about 15 minutes.

11. The cement of claim 10 wherein the cement has a transition time of less than about 12 minutes.

12. The cement of claim 2 wherein the pumice has a reasonably uniform particle size of less than about 120 um.

13. The cement of claim 2 wherein the pumice has a reasonably uniform particle size of less than about 100 um.

14. The cement of claim 2 wherein the pumice has a reasonably uniform particle size of less than about 80 um.

15. The cement of claim 2 wherein the pumice has a reasonably uniform particle size of less than about 70 um.

16. A method of cementing a subterranean well, comprising the steps of preparing a cement composition of one of claims 1-15, placing the cement composition in the well, allowing the cement composition to set.

17. Use of the cement composition of one of claims 1-15 in cementing a subterranean well.