Sorel cements and methods of making and using same

• US 7,654,326 B1
• Filed: 07/10/2008
• Issued: 02/02/2010
• Est. Priority Date: 07/10/2008
• Status: Expired due to Fees

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company), Robert A. Kent
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Gordon, Christopher L., Pewitt, Keith D, King, Dwain, Santra, Ashok, Bour, Daniel L.
• Primary Examiner(s): SUCHFIELD, GEORGE A
• Application Number:
  US12/217,950
• Publication Number:
  US 20100006288A1
• Time in Patent Office: 572 Days
• Field of Search: None
• US Class Current: 166/292
• CPC Class Codes: C04B 14/304 Magnesia
• CPC Class Codes: C04B 2103/22 Set retarders
• CPC Class Codes: C04B 22/066 Magnesia; Magnesium hydroxide
• CPC Class Codes: C04B 22/124 Chlorides of ammonium or of the alkali or alkaline earth metals, e.g. calcium chloride
• CPC Class Codes: C04B 22/16 containing phosphorus in the anion, e.g. phosphates
• CPC Class Codes: C04B 28/32 Magnesium oxychloride cements, e.g. Sorel cement
• CPC Class Codes: C04B 40/0028 Aspects relating to the mixing step of the mortar preparation
• CPC Class Codes: C09K 8/487 Fluid loss control additives; Additives for reducing or preventing circulation loss

Abstract

A method of servicing a wellbore comprising contacting a metal oxide, a soluble chloride or phosphate salt, water, and a liquid retarder to form a cement composition via a continuous process, wherein the liquid retarder is an aqueous solution having a concentration of less than about 25 w/v %, placing the cement composition into the wellbore, and allowing the cement composition to set. A method of servicing a wellbore comprising (a) contacting an aqueous solution with a soluble salt to form a salt solution, (b) contacting an aqueous solution with a solid retarder to form a liquid retarder wherein the liquid retarder has concentration of less than about 25 w/v %, (c) contacting water, the salt solution, and the liquid retarder to form a mixture, (d) contacting the mixture with a metal oxide to form a cement slurry, wherein the cement slurry is produced with an output rate of from about 0.5 barrels per minute to about 20 barrels per minute, (e) placing the cement slurry into the wellbore, and (f) allowing the cement slurry to set.

Claims

1. A method of servicing a wellbore comprising:

(a) contacting an aqueous solution with a soluble salt to form a salt solution;

(b) contacting an aqueous solution with a solid retarder to form a liquid retarder wherein the liquid retarder has concentration of less than about 25 w/v %;

(c) contacting water, the salt solution, and the liquid retarder to form a mixture;

(d) contacting the mixture with a metal oxide to form a cement slurry, wherein the cement slurry is produced with an output rate of from about 0.5 barrels per minute to about 20 barrels per minute;

(e) placing the cement slurry into the wellbore; and

(f) allowing the cement slurry to set and form a set cement.

2. The method of claim 1 wherein the cement slurry is placed in the wellbore in a single treatment volume.

3. The method of claim 1 wherein the metal oxide, soluble chloride or phosphate salt, water, and liquid retarder are contacted simultaneously.

4. The method of claim 1 wherein the cement slurry is formed as a continuous process comprising the continuous addition of the metal oxide, soluble chloride or phosphate salt, water, and liquid retarder to a mixing device and the continuous removal of the cement slurry from the mixing device and placement thereof into the wellbore.

5. The method of claim 1 wherein the liquid retarder is selected from the group consisting of sodium hexametaphosphate, potassium magnesium phosphate hexahydrate, potassium magnesium hexametaphosphate, and combinations thereof.

6. The method of claim 1 wherein the liquid retarder comprises an aqueous solution of sodium hexametaphosphate.

7. The method of claim 1 wherein the metal oxide comprises an alkaline earth metal oxide.

8. The method of claim 7 wherein the alkaline earth metal oxide comprises magnesium oxide.

9. The method of claim 8 wherein the magnesium oxide is selected from the group consisting of dead-burned magnesium oxide, hard-burned magnesium oxide, light-burned magnesium oxide, and combinations thereof.

10. The method of claim 1 wherein the soluble salt is selected from the group consisting of an alkaline earth metal chloride, magnesium chloride, magnesium chloride hexahydrate, sodium phosphate, potassium phosphate, ammonium phosphate, and combinations thereof.

11. The method of claim 1 wherein the soluble salt is dissolved in an aqueous solution.

12. The method of claim 11, wherein the soluble salt has a concentration in the aqueous solution of from about 10 wt. % to about 70 wt. % by total weight of the aqueous solution.

13. The method of claim 1 wherein the liquid retarder is present in an amount of from about 0.05 wt. % to about 15 wt. % by weight of the magnesium oxide.

14. The method of claim 1 wherein the metal oxide and the soluble salt is present in the cement composition in a ratio of from about 2:

1 to about 1;

1.

15. The method of claim 1 wherein the water is present in an amount of from about 10 wt. % to about 200 wt. % by weight of the metal oxide and soluble salt.

16. The method of claim 1 wherein the slurry displays a right angle set.

17. The method of claim 1 wherein the set cement has a compressive strength of from about 50 psi to about 20,000 psi.

18. The method of claim 1 wherein the slurry has a thickening time of greater than about 40 minutes.

19. The method of claim 1 wherein steps (c) and (d) are carried out simultaneously in a recirculating mixer.

20. The method of claim 1 wherein the cement slurry is prepared in a treatment volume of greater than about 25 barrels.