Viscosity reduction

1. A well treatment method, comprising:

introducing into the well an aqueous treatment fluid comprising a polysaccharide, a crosslinker, an organic peroxide, a soluble amine compound and a functional break delay agent;

wherein the soluble amine compound has the R 3 R 4 N((CR 5 R 6 ) 2 —NR 7 ) n —R 8 wherein n is from 2 to 8 and wherein R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are independently selected from hydrogen, alkyl, hydroxyalkyl, and combinations thereof;

wherein a weight ratio of the soluble amine to organic peroxide is from about 1:1 to about 20:1; and,

breaking the treatment fluid.

2. The method of claim 1 wherein the peroxide comprises peroxyester and the functional break delay agent comprises at least one of triethylamine and triethanolamine.

3. The method of claim 1 comprising fracturing a subterranean formation penetrated by the well, contacting the formation with the treatment fluid and breaking the treatment fluid in the formation.

4. A well treatment method, comprising:

introducing an aqueous treatment fluid comprising a viscosifying polymer into the well, and

contacting the fluid with a breaker package comprising an organic peroxide and an activator to lower an effective concentration of the peroxide to break the fluid, wherein a weight ratio of the activator:organic peroxide is at least about 1:20, and wherein the organic peroxide comprises a peroxyester.

5. The method of claim 4 wherein polymer is crosslinked.

6. The method of claim 4 wherein the polymer is non-crosslinked.

7. The method of claim 4 wherein the polymer comprises polysaccharide.

8. The method of claim 4 wherein the polymer comprises a water soluble synthetic polymer.

9. The method of claim 4 wherein the organic peroxide is present at an effective concentration from about 1 to about 1200 ppm by weight of water in the treatment fluid.

10. The method of claim 4 wherein the organic peroxide is selected from the group consisting of diacyl peroxides, dialkyl peroxides, diperoxyketals, hydroperoxides, peroxydicarbonates, peroxyesters and combinations thereof.

11. The method of claim 4 wherein the organic peroxide is selected from the group consisting of t-alkyl esters of peroxycarboxylic acids, t-alkyl esters of monoperoxydicarboxylic acids, di(t-alkyl) esters of diperoxydicarboxylic acids, alkylene diesters of peroxycarboxylic acids, OO-t-alkyl O -alkyl diesters of monoperoxycarbonic acids and combinations thereof.

12. The method of claim 4 wherein the organic peroxide comprises t-butyl peroxybenzoate.

13. The method of claim 4 wherein the organic peroxide is supported on a finely divided solid slurried in the treatment fluid.

14. The method of claim 4 wherein the activator comprises a polyamine according to the chemical formula R 3 R 4 N((CR 5 R 6 )2—NR 7 ) n —R 8 wherein n is at least 2 and wherein R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are independently selected from hydrogen, alkyl, hydroxyalkyl, and combinations thereof.

15. The method of claim 4 wherein the activator is selected from triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, N-methyl aniline, N,N-dimethyl aniline and combinations thereof.

16. The method of claim 4 wherein the weight ratio of activator:peroxide is from about 1:1 to about 20:1.

17. The method of claim 4 wherein the breaker package further comprises an onset delay agent.

18. The method of claim 4 wherein the breaker package further comprises an amine compound of the formula RR 1 NR 2 wherein R, R 1 , and R 2 are independently selected from hydrogen, alkyl, hydroxyalkyl, and combinations thereof.

19. The method of claim 4 wherein the breaker package further comprises triethylamine or triethanolamine.

20. The method of claim 4 wherein the treatment fluid comprises a stabilizer.

21. The method of claim 4 wherein the treatment fluid comprises sodium thiosulfate.

22. The method of claim 4 wherein the treatment comprises fracturing a formation penetrated by the well.

23. The method of claim 4 wherein the treatment fluid further comprises proppant.

24. The method of claim 4 wherein the breaker package is added to the treatment fluid before or during the introduction into the well.

25. The method of claim 4 wherein the breaker package is injected into a formation penetrated by the well in a separate fluid stage to mix with the treatment fluid in the formation.

26. The method of claim 4 wherein the breaker package is injected into the well in a separate fluid stage after the treatment fluid to initiate the contact in the well or in a formation penetrated by the well.

27. The method of claim 4 wherein the polymer is broken in a window from about 5 minutes up to less than about 150 minutes following the contact.

28. A well treatment method, comprising:

introducing an aqueous treatment fluid comprising a viscosifying polymer into the well, and

contacting the polymer with a peroxyester effective to break the fluid viscosity.

29. A well treatment method, comprising:

designing a well treatment job with a specified window to break an aqueous treatment fluid;

wherein the aqueous treatment fluid comprises a viscosifying polymer, an organic peroxide breaker and a delay agent to controllably delay the breaker;

adjusting a proportion of the peroxide breaker, delay agent or combination thereof in the treatment fluid to control the polymer break window to match the specified break window; and

introducing the aqueous treatment fluid into the well according to the treatment job design.

30. A well treatment method, comprising:

introducing an aqueous treatment fluid comprising a viscosifying polymer into the well, and

contacting the polymer with a breaker package comprising an organic peroxide and a breaker delay agent, wherein the delay agent has the formula RR 1 NR 2 wherein R, R 1 , and R 2 are independently selected from hydrogen, alkyl, hydroxyalkyl, and combinations thereof.

31. A well treatment method, comprising:

introducing an aqueous treatment fluid comprising a viscosifying polymer into the well, and

contacting the fluid with a breaker package comprising an organic peroxide and an activator to lower an effective concentration of the peroxide to break the fluid, wherein the weight ratio of activator:peroxide is from about 1:1 to about 20:1.

32. A well treatment method, comprising:

introducing an aqueous treatment fluid comprising a viscosifying polymer and a stabilizer into the well, and

contacting the fluid with a breaker package comprising an organic peroxide and an activator to lower an effective concentration of the peroxide to break the fluid, wherein a weight ratio of the activator:organic peroxide is at least about 1:20.

33. A well treatment method, comprising:

introducing an aqueous treatment fluid comprising a viscosifying polymer into the well, and

contacting the fluid with a breaker package comprising an organic peroxide and an activator to lower an effective concentration of the peroxide to break the fluid, wherein a weight ratio of the activator:organic peroxide is at least about 1:20,

wherein the polymer is broken in a window from about 5 minutes up to less than about 150 minutes following the contact.