RADIALLY SUPPORTED SEAL AND METHOD

Abstract

A seal includes a mandrel having a plurality of radially directed openings therethrough; a plurality of members disposed within the openings and radially displacable therein; and an element disposed about the mandrel and radially displacable by the plurality of members and method.

Description

BACKGROUND

In the hydrocarbon recovery industry, seals are often required in the downhole environment for a plethora of reasons that are familiar to one of ordinary skill in the art. Setting of these seals can be accomplished in a number of ways including mechanical axial compression, inflation, etc. While mechanical compression is reliable, the seals tend to be regularly annular and may not always seal well in an open hole or irregularly shaped cased hole because the setting environment is other than regularly annular. Inflatables are more conformable to the exact shape of the setting hole but suffer from temperature induced pressure changes that can, under some conditions, deleteriously affect the sealing contact pressure and therefore promote leaks. Since sealing in the downhole environment is both important and not likely to be supplanted in the foreseeable future, alternate configurations to create and maintain a seal are always well received by the art.

SUMMARY

A seal includes a mandrel having a plurality of radially directed openings therethrough; a plurality of members disposed within the openings and radially displacable therein; and an element disposed about the mandrel and radially displacable by the plurality of members.

A method for creating a seal includes running into a downhole environment a mandrel having a plurality of radially directed openings therethrough; a plurality of members disposed within the openings and radially displacable therein; and an element disposed about the mandrel and radially displacable by the plurality of members; causing the plurality of members to radially displace thereby contacting the element; and urging the element into loaded contact with a separate structure.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings wherein like elements are numbered alike in the several Figures:

FIG. 1 is a schematic cross-sectional representation of a radially supported seal as disclosed herein in a run-in position;

FIG. 2 is the configuration of FIG. 1 in a deployed position;

FIG. 3 is a schematic cross-sectional representation of a radially supported backup for a seal as disclosed herein in a run-in position; and

FIG. 4 is the configuration of FIG. 3 in a deployed position.

DETAILED DESCRIPTION

Referring to FIG. 1, a configuration 10 capable of mechanically producing a radially supported seal structure is illustrated in the run-in position. The configuration 10 includes a mandrel 12, upon which is mounted an element 14. Element 14 may be mounted upon mandrel 12 in a number of commercially recognizable ways, one of which being by end rings 16 and 18 that limit ends of the element against unintended axially or radially movement relative to the mandrel 12. The foregoing sentence should be understood to indicate that fixation can be achieved or that intended movement can be achieved while unintended movement is inhibited. It will be appreciated that in some constructions of element 14, axial shortening or the run-in length dimension between rings 16 and 18 is required for the element 14 to move radially outwardly as is necessary for sealing against an open or cased hole in which the configuration is intended to be set. Whether or not this is the case depends upon the type of element and its mode of action. More specifically, if the element itself is not substantially elastic in at least the axial direction, shortening will be necessary. Alternatively, if elasticity is available in the element 12, axial movability may be reduced or eliminated.

In either case, the configuration 10 utilizes a plurality of radially extensible members 20. The members are each positioned in openings 22 extending through the mandrel in a substantially radial direction. In one embodiment, the openings are smooth bore structures while in other embodiments, the openings are configured to allow movement of the members 20 therethrough in a single direction. As illustrated, the direction is radially outward although it will be appreciated that they could be configured for radially inward movement.

As illustrated, the members 20 are actuatable in a radially outward direction based upon the application of a force at a radially inward end 24 of each member 20. This force may be applied via a fluid pressure or may be applied via a mechanical or electrical actuator such as a ramped structure (e.g. a cone), or a solenoid, respectively, for example. In the event that a smooth bore is exhibited in openings 22, a radial force must be maintained on the members 20 to keep them in position. Alternatively, if they are not smooth but rather are configured to allow movement of the members 20 in only one direction, such as in the case of a ratchet profile and suitable ratchet following structure on the members 20, then the radial force on the members need only be maintained until the setting procedure is complete whereafter because the members 20 would not be able to retract, there is no reason to maintain the radial force thereon.

The members 20, regardless of smooth or profiled bore embodiments, are positioned to be capable of contacting an inside dimension of the element 14 and urging that element radially so that it comes into loaded contact with a casing or open hole with which the element is intended to create a seal. Reference is made to FIG. 2 wherein the deployed or sealed position of the configuration 10 is illustrated. The members 20 are intended to remain in the extended position illustrated in FIG. 2 for the duration of the life of the seal. This will ensure that the element 14 remains in contact with the casing or open hole even with changes in temperature in the wellbore.

In a variation of this embodiment, the element 14 includes at a surface 26 thereof with which the members 20 are to come in contact, a force spreading arrangement. This is because the members 20 are contemplated to be about 1 to about 2 inches in diameter meaning they are relatively small and will thus cause a significant point load on the element 14 if not used with a force spreading arrangement. At least one of the members is configured to contact the force spreading arrangement. One force spreading arrangement contemplated includes a number of traditional packer ribs, while another arrangement includes a reinforcing fabric or mesh material. Further, combinations of such force spreading arrangements are also contemplated.

Referring to FIGS. 3 and 4, an alternate embodiment is illustrated wherein the concept discussed in connection with FIGS. 1 and 2 is applied as a backup configuration for an element in a seal configuration. One seal configuration that can benefit from the embodiment of FIGS. 3 and 4 is a swellable element 114. Swellable elements are by nature composed of relatively soft material. Because, hereof, they are also subject to being swabbed off the mandrel on which they are mounted. Such a condition, of course, will defeat any seal the swellable material had previously created when set. As this is clearly undesirable, configurations capable of backing-up the swellable element are useful. The concept as described above employing radially moving members to support a material in loaded contact with a wall, is utilized for this backup purpose as is illustrated in FIGS. 3 and 4.

Several members 120 are positioned at each axial end of the configuration 110. The members 120 are actuated identically to those discussed hereinabove. Because of the mechanical backup of the backup elements 130, the element 114 cannot be extruded easily. In addition hereto, it is further noted that the element 14 may also comprise a swellable material for additional sealing capability.

While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.

Claims

1. A seal comprising;

a mandrel having a plurality of radially directed openings therethrough;

a plurality of members disposed within the openings and radially displacable therein; and

an element disposed about the mandrel and radially displacable by the plurality of members.

2. The seal as claimed in claim 1 further comprising a force spreading arrangement located as a point of contact between at least one of the plurality of members and the element.

3. The seal as claimed in claim 2 wherein the force spreading arrangement is a plurality of packer ribs.

4. The seal as claimed in claim 2 wherein the force spreading arrangement is a mesh.

5. The seal as claimed in claim 1 wherein the element comprises a material that is at least partially nonelastic.

6. The seal as claimed in claim 1 wherein the element comprises a material that is at least partially an elastic material.

7. The seal as claimed in claim 1 wherein the element comprises a swellable material.

8. The seal as claimed in claim 1 wherein the plurality of members are evenly distributed about the mandrel and over a length thereof.

9. The seal as claimed in claim 1 wherein the plurality of members are distributed about the mandrel and restricted to at least one axial region of the mandrel adjacent the element.

10. The seal as claimed in claim 1 wherein the plurality of members are distributed about the mandrel and restricted to two axial regions of the mandrel, one adjacent each axial end of the element.

11. The seal as claimed in claim 10 wherein the axial regions bound a region of the mandrel supporting a primary element.

12. The seal as claimed in claim 11 wherein the primary element is a swellable material.

13. The seal as claimed in claim 1 wherein the plurality of members are responsive to a pressure change inside the mandrel to radially extend into contact with the element.

14. The seal as claimed in claim 1 wherein the plurality of members are responsive to a ramped structure passed into the mandrel to radially extend into contact with the element.

15. The seal as claimed in claim 1 wherein the plurality of members are actuated via solenoid.

16. A method for creating a seal comprising:

running the seal of claim 1 into a downhole environment;

causing the plurality of members to radially displace thereby contacting the element; and

urging the element into loaded contact with a separate structure.

17. The method as claimed in claim 16 wherein the causing is by pressuring up on an inside dimension of the mandrel.

18. The method as claimed in claim 16 wherein the causing is by running a cone through an inside dimension of the mandrel.

19. The method as claimed in claim 16 wherein the causing is by actuating a solenoid.

20. The method as claimed in claim 16 wherein the contacting the element includes spreading a contact force of at least one of the plurality of members over a surface area of the element greater than a surface area of that member.