DOWNHOLE SEAL AND ANCHOR RELEASING SYSTEM AND METHOD
A downhole seal and anchor releasing device includes, a seal defeatable via a first pull, an anchor releasable via a second pull, and an energy dissipation device configured to dissipate enough energy from the first pull subsequent defeat of the seal to prevent release of the anchor in response to the first pull
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It is common in the hydrocarbon recovery industry to anchor a tool or tubular from a downhole location and to also seal off the borehole at or near the anchor point. One such example is at a whipstock where one leg of the well is sealed off while another leg remains open, for example, to allow continued production. At times, it is desirable to remove both the seal and the anchor. When doing so, however, it may be desirable to equalize any pressure differential across the seal and even release the seal itself, prior to releasing the anchor to prevent excessive movement of the tool that could result during the sudden pressure equalization process if the anchor is released prior to equalization of the pressure. Devices and methods that provide for separate pressure equalization and release control of the seal and the anchor would be well received in the art.
BRIEF DESCRIPTION OF THE INVENTIONDisclosed herein is a downhole seal and anchor releasing device. The device includes, a seal defeatable via a first pull, an anchor releasable via a second pull, and an energy dissipation device configured to dissipate enough energy from the first pull subsequent defeat of the seal to prevent release of the anchor in response to the first pull.
Further disclosed herein is a downhole seal and anchor releasing method. The method includes, defeating the seal with a first pull, dissipating energy subsequent to defeating of the seal such that energy remaining from the first pull is below an energy threshold required to release the anchor, and releasing the anchor with a second pull.
Further disclosed herein is a downhole seal and anchor releasing system. The system includes, a seal sealably engagable with a downhole structure, a valve in functional communication with the seal configured to bypass the seal in response to a first pull, an anchor engagable with the downhole structure and releasable with a second pull, and an energy dissipation device configured to dissipate energy from the first pull sufficient to prevent release of the anchor subsequent to the first pull and advance of the second pull.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
Referring to
Embodiments described herein address this issue by incorporation of the energy dissipation device 26. In the first embodiment the energy dissipation device 26 dissipates energy after initiation of pressure equalization and before release of the seal 18 and anchor 22, so that any remaining energy is unable to exert forces on the seal 18 and anchor 22 that are greater than a release force threshold necessary to release the seal 18 and anchor 22. In so doing, the device 10 allows an operator to separately control the pressure equalization process from the release of the seal 18 and release of the anchor 22. A detailed review of the device 10 follows.
In the embodiment of
Referring to
Movement of the mandrel 30 relative to the inner sleeve 78 (and the device 10) can be controlled from surface. A coupling 96, on an uphole end of the mandrel 30, can be connected to a drillstring (not shown), for example, that extends to surface. With such connection, the mandrel 30 can be pulled from the surface via the drillstring. In the present embodiment, with the seal 18 in sealing engagement with the walls 14 and the anchor 22 anchored to the walls 14, a pull on the mandrel 30, from surface, can cause the mandrel 30 to move from a position wherein fluidic communication between the annular spaces 50 and 54 is blocked to a position wherein the fluidic communication between the annular spaces 50 and 54 is allowed, as described above. Such movement of the mandrel 30 relative to the inner sleeve 78 may, however, be prevented until a force of the pull exceeds a threshold required to cause a force failing member 98 (illustrated in this embodiment as a shear ring) to fail. This shear ring 98 can prevent unintentional actuation of the bypass valve 46, until desired, by requiring a specified pull force threshold to be attained to shear the shear ring 98.
The pull force required to shear the shear ring 98, however, causes energy to be stored in the elasticity of the length of drillstring between the device 10 and surface. As the shear ring 98 fails and the drillstring recoils, some of the energy, stored in the drillstring, is converted into kinetic energy. This recoil action can create a hammering effect on a second force failing member 102, disclosed in this embodiment as a release stud 102 that is designed to release both the seal 18 and the anchor 22 in response to a pull having a force greater than a selected threshold. If not for the inclusion of the energy-dissipating device 26, disclosed in embodiments herein, the dynamic nature of the hammering action from the recoil could result in sufficient force (applied over a short time duration) to exceed the threshold force of the release stud 102 causing an undesirable failure and premature release of the seal 18 and the anchor 22. It is the inclusion of the energy-dissipating device 26; therefore, that prevents such premature and undesirable failure.
A review of
Continuing reference to
After the release stud 102 has failed, additional movement of the mandrel 30, in an uphole direction, causes a shoulder 122 on the mandrel 30 to contact a key 126 that is fixed to the inner sleeve 78, thereby causing the inner sleeve 78 to move in an uphole direction. Engagement of the inner sleeve 78 with a shoulder 80 of the upper seal housing causes the upper seal housing 66, to move uphole also. Movement of the upper seal housing 66 in an uphole direction moves an upper guide ring 130, attached thereto, in an uphole direction and away from a lower guide ring 134, located on a downhole side of the seal 18. This separational movement of the two guide rings 130, 134 reduces axial compression of the packing elements 34 of the seal 18 from the two guide rings 130, 134 causing the packing elements 34 to reduce a radial dimension thereof until the seal 18 is no longer in sealing engagement with the walls 14. Alternate embodiments of the present invention can rely directly upon disengagement of the seal 18 from the walls 14 to equalize any pressure differential thereacross instead of utilizing the bypass valve 46 described above. Such an embodiment is described below with reference to
Referring to
Referring to
Referring to
As the shear ring 98 fails in response to the force of the pull, the energy stored in the elasticity of the drillstring is released in recoil. The recoil urges the mandrel 30 to move upward at a high rate that is prevented by the energy dissipation device 166. The energy dissipation device 166 includes a piston 170 that is attached to the release stud 158 through threadable engagement or welding, for example. The piston 170 is housed within a chamber 174 defined by the lower cone 178. One or more opening(s) 182 in the lower cone 178 allow the fluid 118 located in the chamber 174 to be pumped from the chamber 174 at a controlled rate. The controlled flow rate of fluid 118 slows the rate of upward movement of the piston 170 thereby decreasing the hammering effect as a travel distance of the piston 170 is exhausted, thereby preventing failure of the release stud 158 and the shear screws 162 from the first pull.
Referring to
While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
Claims
1. A downhole seal and anchor releasing device, comprising:
- a seal defeatable via a first pull;
- an anchor releasable via a second pull; and
- an energy dissipation device configured to dissipate enough energy from the first pull subsequent defeat of the seal to prevent release of the anchor in response to the first pull.
2. The downhole seal and anchor releasing device of claim 1, wherein the seal and anchor are in operable communication with a whipstock.
3. The downhole seal and anchor releasing device of claim 1, further comprising a bypass valve configured to equalize pressure across the seal prior to release of the seal from sealing engagement with a tubular.
4. The downhole seal and anchor releasing device of claim 1, wherein the seal is configured to equalize pressure thereacross in response to being released prior to release of the anchor.
5. The downhole seal and anchor releasing device of claim 1, wherein a force threshold to release the anchor less than twice a force threshold to defeat the seal.
6. The downhole seal and anchor releasing device of claim 1, wherein the energy dissipation device includes at least one of a spring, a fluid dampener and a crushable member.
7. The downhole seal and anchor releasing device of claim 6, wherein the spring is a cupped spring washer.
8. The downhole seal and anchor releasing device of claim 6, wherein the fluid dampener includes a chamber with fluid therein and at least one opening in the chamber for escape of the fluid from the chamber in response to a piston moving within the chamber.
9. The downhole seal and anchor releasing device of claim 8, wherein the fluid is at least one of, oil, grease and water.
10. The downhole seal and anchor releasing device of claim 1, further comprising a first force failing member for releasably positioning the seal and a second force failing member for releasably positioning the anchor.
11. The downhole seal and anchor releasing device of claim 1, wherein at least one of the first pull and the second pull are from surface.
12. A downhole seal and anchor releasing method, comprising:
- defeating the seal with a first pull;
- dissipating energy subsequent to defeating of the seal such that energy remaining from the first pull is below an energy threshold required to release the anchor; and
- releasing the anchor with a second pull.
13. The downhole seal and anchor releasing method of claim 12, wherein the dissipating energy includes increasing stored energy of an energy storing member.
14. The downhole seal and anchor releasing method of claim 12, wherein the dissipating energy includes pressurizing a fluid and flowing at least a portion of the pressurized fluid through at least one opening.
15. The downhole seal and anchor releasing method of claim 12, wherein the dissipating energy includes crushing a crushable member.
16. The downhole seal and anchor releasing method of claim 12, further comprising decreasing a pressure differential across the seal subsequent to release of the seal and prior to release of the anchor.
17. The downhole seal and anchor releasing method of claim 12, wherein a force of the second pull is less than twice a force of the first pull.
18. The downhole seal and anchor releasing method of claim 12, wherein defeating the seal includes failing a force failing member.
19. The downhole seal and anchor releasing method of claim 12, wherein releasing the anchor includes failing a force failing member.
20. A downhole seal and anchor releasing system comprising:
- a seal sealably engagable with a downhole structure;
- a valve in functional communication with the seal being configured to bypass the seal in response to a first pull;
- an anchor engagable with the downhole structure and releasable with a second pull; and
- an energy dissipation device configured to dissipate energy from the first pull sufficient to prevent release of the anchor subsequent to the first pull and advance of the second pull.
Type: Application
Filed: Oct 6, 2008
Publication Date: Apr 8, 2010
Applicant: BAKER HUGHES INCORPORATED (Houston, TX)
Inventors: Gregory L. Hern (Porter, TX), Charles W. Pleasants (Cypress, TX)
Application Number: 12/246,180
International Classification: E21B 23/00 (20060101);