Method of fracking using silicone surfactants

1. A method of fracking subterranean petroleum or gas formations, the method comprising

admixing liquefied carbon dioxide with a solution of an oil and a surfactant of Formula I to obtain a substantially water-free foam; and

injecting the substantially water-free foam into a well formed in the subterranean petroleum or gas formation, at a pressure sufficient to create a fissure or to open an existing fissure;

wherein the formula (I) is:

M a D x T y Q b ;

and wherein:

M is (R 1 ) 3 SiO p where p is 1/2;

D is R 2 R 3 SiO q where q is 2/2;

T is R 4 R 5 SiO r where r is 3/2;

Q is SiO s where s is 4/2;

a ranges from 2 to 10;

x ranges from 8 to 500;

y ranges from 0 to 10;

b ranges from 0 to 10;

each of R 1 , R 2 , R 3 , R 4 , and R 5 is independently, at each occurrence, C 1 -C 250 alkyl, or C 1 -C 250 alkenyl;

wherein the method is a substantially water-free fracking method.

2. The method of claim 1 , wherein the surfactant of Formula I has a structure of Formula II:

wherein

R 1 , R 2 , and R 3 are independently C 1 -C 6 alkyl;

R 4 and R 5 are independently, at each occurrence, C 1 -C 250 alkyl, provided at least one of R 4 or R 5 is C 12 -C 250 alkyl;

x ranges from 8 to 500; and

y ranges from 1 to 10;

where 10<x+y≤500.

3. The method of claim 2 , wherein the surfactant of Formula II has the structure of Formula III:

wherein

each R 1 is independently, at each occurrence, C 1 -C 6 alkyl;

x ranges from 8 to 500;

y ranges from 1 to 10;

where 10<x+y≤500; and

n ranges from 9 to 250.

4. The method of claim 3 , wherein the surfactant comprises at least 50 dimethyl siloxane repeating units.

5. The method of claim 2 , wherein each R 1 is methyl.

6. The method of claim 2 , wherein each R 2 and R 3 are methyl.

7. The method of claim 2 , wherein the surfactant comprises at least 50 dimethyl siloxane repeating units.

8. The method of claim 1 , wherein the surfactant of Formula I has a structure of Formula IV:

wherein

each R 1 is independently, at each occurrence, C 1 -C 250 alkyl;

each of R 2 and R 3 is independently, at each occurrence, C 1 -C 6 alkyl;

with the proviso that at least one R 1 is C 12 -C 250 alkyl;

and

8<x≤500.

9. The method of claim 8 , wherein the surfactant of Formula IV has a structure of Formula V:

wherein

each R 1 is independently, at each occurrence, C 1 -C 6 alkyl;

each of R 2 and R 3 is independently, at each occurrence, C 1 -C 6 alkyl;

8<x≤500; and

n ranges from 9 to 250.

10. The method of claim 1 , wherein the solution of an oil and a surfactant comprises from about 0.01 weight % to about 10 weight % of the surfactant in the oil.

11. The method of claim 1 , wherein the solution of an oil and a surfactant comprises from about 0.1 weight % to about 3 weight % of the surfactant in the oil.

12. The method of claim 1 , wherein from about 30 weight % to about 99 weight % liquefied carbon dioxide is admixed with from about 70 weight % to about 1 weight % of the solution of an oil and a surfactant.

13. The method of claim 1 , wherein from about 50 weight % to about 75 weight % liquefied carbon dioxide is admixed with from about 50 weight % to about 25 weight % of the solution of an oil and a surfactant.

14. The method of claim 1 , wherein a viscosity of the substantially water-free foam is at least about two times (2×) an initial viscosity, wherein the initial viscosity is the viscosity of the liquefied carbon dioxide prior to admixing the liquefied carbon dioxide with said solution of an oil and a surfactant.

15. The method of claim 1 , wherein the substantially water-free foam is stable for a period of up to 10 hours.

16. The method of claim 1 , wherein the substantially water-free foam is stable for a period of up to 6 hours.

17. The method of claim 1 , wherein the oil in said solution of an oil and a surfactant is crude oil, mineral oil, a plant based oil, diesel, kerosene, gasoline, jet fuel or synthetic oil.

18. The method of claim 1 , further comprising injecting proppants into the petroleum or gas well.

19. A method of fracking subterranean petroleum or gas formations, the method comprising

admixing liquefied carbon dioxide with a solution of an oil and a surfactant of Formula III to obtain a substantially water-free foam; and

injecting the substantially water-free foam into a well formed in the subterranean petroleum or gas formation, at a pressure sufficient to create a fissure or to force open an existing fissure;

wherein the formula (III) is:

wherein

each R 1 is independently, at each occurrence, C 1 -C 6 alkyl;

x ranges from 8 to 500;

y ranges from 0 to 10;

where 10<x+y≤500; and

n ranges from 10 to 30;

and further wherein from about 50 weight % to about 75 weight % liquefied carbon dioxide is admixed with from about 50 weight % to about 25 weight % of the solution of an oil and a surfactant, wherein said solution of an oil and a surfactant comprises about 0.1 weight % to about 3 weight % of the surfactant in the oil;

and wherein the method is a substantially water-free fracking method.