Packing element booster
A packer is provided for sealing an annular region in a wellbore. In one embodiment, the, packer includes a boosting assembly adapted to increase a pressure on the packing element in response to an increase in a pressure surrounding the packer, for example, an increase in the annulus pressure.
1. A packer, comprising:
a mandrel;
a packing element disposed circumferentially around an outer surface of the mandrel; and
a boosting assembly disposed on the outer surface of the mandrel, wherein the boosting assembly includes a housing, a booster sleeve, and a sealed pressure chamber defined by the housing and the booster sleeve, wherein the booster sleeve is movable toward the packing element in response to an external force to exert a force on the packing element and decrease a volume of the pressure chamber, and wherein the sealed pressure chamber is separated from the mandrel.
2. The packer of claim 1 , further comprising a motion limiting member disposed between the housing and the booster sleeve.
3. The packer of claim 1 , further comprising a packing cone member disposed between the boosting assembly and the packing element.
4. The packer of claim 3 , wherein the packing cone member is selectively connected to at least one of the housing and the booster sleeve.
5. The packer of claim 3 , further comprising a seal member disposed between the packing cone member and the mandrel.
6. The packer of claim 1 , further comprising a fluid path to communicate the external pressure to the boosting assembly.
7. The packer of claim 6 , wherein the force exerted corresponds to the external pressure.
8. The packer of claim 1 , further comprising a second boosting assembly disposed on a side opposite the first boosting assembly, wherein the packing element is positioned between the first boosting assembly and the second boosting assembly.
9. The packer of claim 1 , further comprising a slip.
10. The packer of claim 9 , wherein the slip is releasable after actuation.
11. The packer of claim 9 , further comprising a slip cone member adapted to urge the slip radially outward.
12. The packer of claim 9 , wherein the slips are activated by a first force and the booster sleeve applies a second force to the slips.
13. The packer of claim 1 , wherein the pressure chamber is at about atmospheric pressure.
14. The packer of claim 1 , wherein the pressure chamber remains sealed during the operation of the packer.
15. The packer of claim 1 , wherein the packing element is movable between an initially retracted position, an expanded position and a subsequently retracted position.
16. The packer of claim 15 , wherein the pressure chamber is sealed when the packing element is in the subsequently retracted position.
17. The packer of claim 1 , wherein the chamber is sealed using at least one sealing member disposed between the housing and the booster sleeve.
18. A method of sealing a tubular in a wellbore, comprising:
placing a sealing apparatus in the tubular, the sealing apparatus including:
a mandrel;
a packing element disposed circumferentially around an outer surface of the mandrel; and
a boosting assembly disposed on the outer surface of the mandrel, wherein the boosting assembly includes a housing, a booster sleeve, and a pressure chamber enclosed by the housing and the booster sleeve, wherein the pressure chamber is isolated from a pressure in the wellbore;
expanding the packing element into engagement with the tubular while maintaining a size of the chamber; and
applying a pressure to the booster sleeve, thereby causing the pressure chamber to reduce in size and move the booster sleeve axially to exert a force against the packing element.
19. The method of claim 18 , further comprising placing a second packer in the tubular.
20. The method of claim 19 , further comprising coupling the first packer and the second packer.
21. The method of claim 18 , further comprising preventing the booster sleeve to move in an opposite axial direction.
22. The method of claim 18 , further comprising providing a packing cone member disposed between the boosting assembly and the packing element.
23. The method of claim 22 , further comprising releasably connecting the packing cone member to at least one of the housing and the booster sleeve.
24. The method of claim 18 , further comprising providing a fluid path for communicating a pressure from the annulus to the boosting assembly.
25. The method of claim 24 , wherein the pressure applied to the booster sleeve is the pressure communicated through the fluid path.
26. The method of claim 18 , further comprising providing a second boosting assembly disposed on a side opposite the first boosting assembly, wherein the packing element is positioned between first boosting assembly and the second boosting assembly.
27. The method of claim 18 , further comprising urging a slip toward the tubular.
28. The method of claim 27 , further comprising releasing the slip and retrieving the sealing apparatus.
29. The method of claim 18 , further comprising retracting the packing element such that the packing element moves out of engagement with the tubular, wherein the pressure chamber is isolated from the pressure in the wellbore during the operation of the sealing apparatus.
30. The method of claim 18 , wherein the pressure chamber is isolated from the pressure in the wellbore using at least one sealing member disposed between the housing and the booster sleeve.
31. A method of isolating a zone in a wellbore, comprising:
providing a sealing apparatus having a first packer and a second packer, wherein at least one of the first packer and the second packer includes:
a mandrel;
a packing element disposed circumferentially around an outer surface of the mandrel; and
a first boosting assembly and a second boosting assembly, wherein each of the first and second boosting assemblies include a housing, a booster sleeve, and a pressure chamber enclosed by the housing and the booster sleeve, wherein the pressure chamber is isolated from a pressure in the wellbore;
positioning the sealing apparatus in the wellbore such that the zone is between the first packer and the second packer;
moving the first boosting assembly relative to the mandrel to expand the packing element into engagement with the wellbore; and
applying a pressure to the booster sleeve of the first boosting assembly, thereby causing the pressure chamber of the first boosting assembly to reduce in size and causing the booster sleeve of the first boosting assembly to exert a force against the packing element, wherein the first boosting assembly and the second boosting assembly are actuated by applying pressure from opposite directions.
32. The method of claim 31 , further comprising retracting the packing element such that the packing element moves out of engagement with the tubular, wherein the pressure chamber is isolated from the pressure in the wellbore while retracting the packing element.
33. A method of isolating a zone in a wellbore, comprising:
providing a sealing apparatus having a first packer and a second packer, wherein at least one of the first packer and the second packer includes:
a mandrel;
a packing element disposed circumferentially around an outer surface of the mandrel; and
a boosting assembly having a housing, a booster sleeve, and a pressure chamber enclosed by the housing and the booster sleeve, wherein the pressure chamber is isolated from a pressure in the wellbore;
positioning the sealing apparatus in the wellbore such that the zone is between the first packer and the second packer;
expanding the packing element into engagement with the wellbore without changing a size of the pressure chamber; and
applying a pressure to the booster sleeve, thereby causing the pressure chamber to reduce in size and causing the booster sleeve to exert a force against the packing element, wherein the force exerted is greater than a force used to expand the packing element.
34. A packer, comprising:
a mandrel;
a packing element disposed circumferentially around an outer surface of the mandrel; and
a boosting assembly disposed on the outer surface of the mandrel, wherein the boosting assembly includes a housing, a booster sleeve, and a sealed pressure chamber defined by the housing and the booster sleeve, wherein the booster sleeve is movable toward the packing element in response to an external force to exert a force on the packing element and decrease a volume of the pressure chamber,
wherein the packing element is actuatable while maintaining a size of the pressure chamber.