Method of foaming saturated or near saturated brines with synergistic mixtures

1. A method of foaming a brine which is at least 70 percent saturated, which comprises introducing to the brine a blend comprising:

(i.) at least one foaming agent; and

(ii.) a compound of the formula:

C n H 2n+1 —N—[(CH 2 ) m COOM] 2

wherein n is 4 to 11, M is an alkali metal and m is 1 to 3; and

further wherein the foaming agent of (i.) is different from the compound of (ii.).

2. The method of claim 1 , wherein n is 7 to 8.

3. The method of claim 2 , wherein m is 2.

4. The method of claim 1 , wherein the foaming agent is a quaternary ammonium salt, an alkyl betaine, an alkylamidopropyl betaine, a sulfobetaine, a hydroxysultaine, an amphoteric perfluoroalkylamido sulfonate or an alkylether sulfate.

5. The method of claim 4 , wherein the foaming agent is a mixture of at least two of the following: dodecyliminodipropionate, amphoteric perfluoroalkylamido sulfonate, alkyltrimethyl ammonium chloride, alkylamidopropyl betaine and octyliminodipropionate.

6. The method of claim 1 , wherein the compound of formula (II) is

C 8 H 17 —N—[(CH 2 ) 2 COOM] 2

wherein M is sodium or potassium.

7. The method of claim 1 , wherein the amount of foaming agent of (i.) in the blend is between from about 10 to about 90 weight percent of the total blend.

8. A method of foaming a brine which is at least 70 percent saturated which comprises introducing to the brine a blend comprising:

(i.) at least one foaming agent; and

(ii.) a compound of the formula:

C n H 2n+1 —N—[(CH 2 ) m COOM] 2

wherein n is 4 to 11, M is an alkali metal and m is 1 to 3, and

further wherein the amount of at least one foaming agent in the blend is between from about 10 to about 90 weight percent of the blend and the foaming agent of (i.) is different from the compound of (ii.).

9. The method of claim 8 , wherein n is 7 to 8.

10. The method of claim 8 , wherein m is 2 and M is sodium or potassium.

11. The method of claim 8 , wherein the foaming agent is a quaternary ammonium salt, an alkyl betaine, an alkylamidopropyl betaine, a sulfobetaine, a hydroxysultaine, an amphoteric perfluoroalkylamido sulfonate or an alkylether sulfate.

12. The method of claim 8 , wherein the foaming agent comprises:

between from about 10 to about 70% of disodium octyliminodipropionate;

between from about 7 to about 40% of cocoamidopropyl betaine; and

between from about 10 to about 60% of cocotrimethyl ammonium chloride.

13. The method of claim 12 , wherein the foaming agent comprises:

between from about 20 to about 40% of disodium octyliminodipropionate;

between from about 15 to about 35% of cocoamidopropyl betaine; and

between from about 20 to about 30% of cocotrimethyl ammonium chloride.

14. A method of foaming saturated or near saturated a brine which is at least 70 percent saturated which comprises introducing to the brine a blend comprising:

(i.) at least one foaming agent; and

(ii.) a compound of the formula:

C n H 2n+1 —N—[(CH 2 ) m COOM] 2

wherein n is 4 to 11, M is an alkali metal and m is 1 to 3, and

further wherein the amount of at least one foaming agent in the blend is between from about 10 to about 90 weight percent of the blend and wherein the brine is selected from the group consisting of NaCl, NaBr, HCOONa, KCl, KBr, CsCl, CaCl 2 , CaBr 2 and ZnBr 2 brines; the foaming agent of (i.) being different from the compound of (ii.).

15. The method of claim 14 , wherein n is 7 to 8.

16. The method of claim 14 , wherein m is 2 and M is sodium or potassium.

17. The method of claim 15 , wherein the foaming agent is a quaternary ammonium salt, an alkyl betaine, an alkylamidopropyl betaine, a sulfabetaine, a sultaine, a hydroxysultaine, an amphoteric perfluoroalkylamido sulfonate or an alkylether sulfate.

18. The method of claim 15 , wherein the brine is calcium chloride brine.

19. The method of claim 15 , wherein the brine is sodium chloride brine.

20. The method of claim 15 , wherein the compound of formula (II.) is disodium octyliminodipropionate.