Apparatus, compositions, and methods of breaking fracturing fluids
View Patent ↗Apparatus and compositions for reducing the viscosity of a gelled fluid is provided. In one embodiment, a viscosity reducing microbe is disposed in a capsule and added to the gelled fluid. The gelled fluid may include a thickening agent adapted to increase its viscosity. Upon release from the capsule, the microbe begins to digest the thickening agent in the gelled fluid and/or releases enzymes that that breakdown the thickening agent.
1. A composition for reducing viscosity of a gelled fluid, comprising:
a first amount of a capsule containing a viscosity reducing microbe disposed within the capsule, and
a second amount of non-encapsulated viscosity reducing microbe,
wherein the capsule is adapted to release the viscosity reducing microbe into the gelled fluid over time or in response to a change in a fluid property to release the microbes, where the first and second amounts are adjusted to produce a desired viscosity reduction profile, and where the microbes are selected from the group of hyperthermophilic bacteria and fungi.
2. The composition of claim 1 , wherein the change in the fluid property includes changing a temperature of the fluid, exposing the fluid to an aqueous fluid, changing a pH of the fluid, changing a pressure exerted on the fluid, exposing the fluid to shear, exposing the fluid to an additive designed to remove or destroy the capsule, or a combination of some or all of these deencapsulating conditions.
3. The composition of claim 1 , wherein the change in the fluid property comprises changing a temperature of the fluid to a temperature sufficient to remove or destroy the capsule.
4. The composition of claim 1 , wherein the change in the fluid property comprises exposing the fluid to an aqueous fluid, where the aqueous fluid removes or destroys the capsule.
5. The composition of claim 1 , wherein the change in the fluid property comprises changing a pH of the fluid to a pH sufficient to remove or destroy the capsule.
6. The composition of claim 1 , wherein the change in the fluid property comprises changing a pressure to a pressure sufficient to remove or destroy the capsule.
7. The composition of claim 1 , wherein the change in the fluid property comprises exposing the fluid to shear, where the shear is sufficient to remove or destroy the capsule.
8. The composition of claim 1 , wherein the change in the fluid property comprises exposing the fluid to an additive designed to remove or destroy the capsule.
9. An composition for reducing viscosity of a gelled fluid, comprising:
a first amount of an apparatus comprising:
an outer shell, and
an interior filled with a viscosity reducing microbe, and
a second amount of non-encapsulated viscosity reducing microbe,
where the outer shell is adapted to rupture in response to a change in a fluid property, where the first and second amounts are adjusted to produce a desired viscosity reduction profile, and where the microbes are selected from the group of hyperthermophilic bacteria and fungi.
10. The composition of claim 9 , wherein the change in the fluid property includes changing a temperature of the fluid, exposing the fluid to an aqueous fluid, changing a pH of the fluid, changing a pressure exerted on the fluid, exposing the fluid to shear, exposing the fluid to an additive designed to remove or destroy the outer shell, or a combination of some or all of these deencapsulating conditions.
11. The composition of claim 9 , wherein the change in the fluid property comprises changing a temperature of the fluid to a temperature sufficient to remove or destroy the outer shell.
12. The composition of claim 9 , wherein the change in the fluid property comprises exposing the fluid to an aqueous fluid, where the aqueous fluid removes or destroys the outer shell.
13. The composition of claim 9 , wherein the change in the fluid property comprises changing a pH of the fluid to a pH sufficient to remove or destroy the outer shell.
14. The composition of claim 9 , wherein the change in the fluid property comprises changing a pressure to a pressure sufficient to remove or destroy the outer shell.
15. The composition of claim 9 , wherein the change in the fluid property comprises exposing the fluid to shear, where the shear is sufficient to remove or destroy the outer shell.
16. The composition of claim 9 , wherein the change in the fluid property comprises exposing the fluid to an additive designed to remove or destroy the outer shell.
17. A fluid composition for wellbore operations, comprising:
an aqueous fluid;
a fluid thickener;
a first amount of an unecapsulated viscosity reducing microbe, and
a second amount of a capsule containing a viscosity reducing microbe,
where the capsule is designed to release the microbe in response to a change in a fluid property, where the first and second amounts are adjusted to produce a desired viscosity reduction profile, and where the microbes are selected from the group of hyperthermophilic bacteria and fungi.
18. The composition of claim 17 , wherein the change in the fluid property includes changing a temperature of the fluid, exposing the fluid to an aqueous fluid, changing a pH of the fluid, changing a pressure, exposing the fluid to shear, exposing the fluid to an additive designed to remove or destroy the encapsulating agent, or a combination of some or all of these deencapsulating conditions.
19. The composition of claim 17 , wherein the change in the fluid property comprises changing a temperature of the fluid to a temperature sufficient to remove or destroy the capsule.
20. The composition of claim 17 , wherein the change in the fluid property comprises exposing the fluid to an aqueous fluid, where the aqueous fluid removes or destroys the capsule.
21. The composition of claim 17 , wherein the change in the fluid property comprises changing a pH of the fluid to a pH sufficient to remove or destroy the capsule.
22. The composition of claim 17 , wherein the change in the fluid property comprises changing a pressure to a pressure sufficient to remove or destroy the capsule.
23. The composition of claim 17 , wherein the change in the fluid property comprises exposing the fluid to shear, where the shear is sufficient to remove or destroy the capsule.
24. The composition of claim 17 , wherein the change in the fluid property comprises exposing the fluid to an additive designed to remove or destroy the capsule.
25. The composition of claim 1 , wherein the hyperthermophilic bacteria are selected from the group consisting of Thermotogas bacteria, Bacillus bacteria, Citrobacter bacteria, and Enterococcus bacteria.
26. The composition of claim 1 , wherein the microbes and fungi are selected from the group consisting of Thermotoga neapolitana, Thermotoga maritime, Bacillus subtilis, Citrobacter freundii , and Enterococcus faecalies , and Aspergillus niger.
27. The composition of claim 9 , wherein the hyperthermophilic bacteria are selected from the group consisting of Thermotogas bacteria, Bacillus bacteria, Citrobacter bacteria, and Enterococcus bacteria.
28. The composition of claim 9 , wherein the microbes and fungi are selected from the group consisting of Thermotoga neapolitana, Thermotoga maritime, Bacillus subtilis, Citrobacter freundii , and Enterococcus faecalies , and Aspergillus niger.
29. The composition of claim 17 , wherein the hyperthermophilic bacteria are selected from the group consisting of Thermotogas bacteria, Bacillus bacteria, Citrobacter bacteria, and Enterococcus bacteria.
30. The composition of claim 17 , wherein the microbes and fungi are selected from the group consisting of Thermotoga neapolitana, Thermotoga maritime, Bacillus subtilis, Citrobacter freundii , and Enterococcus faecalies , and Aspergillus niger.