Actuator Assembly for Tubular Expansion
A hydraulically powered downhole tool includes a tool mandrel (20) having an interior bore (22), and a plurality of pistons (26) each axially movable relative to the tool mandrel and mechanically interconnected by an outer sleeve (24) exterior of the tool mandrel. A plurality of mandrel sections and a plurality of outer sleeve sections each have a lower end for interconnection with an upper end of a corresponding member. A retainer (28), (29) is provided for supporting each outer sleeve section above a respective lower sleeve section, thereby exposing mandrel sections for vertical assembly.
The present invention relates to an actuator assembly for positioning in a well to actuate a downhole tool. More particularly, this invention relates to a hydraulically powered actuator assembly for suspending in the well from a workstring and producing high forces suitable for radially expanding a downhole tubular.
BACKGROUND OF THE INVENTIONVarious types of downhole actuators are used for operating specific downhole equipment in a well. Actuators may be hydraulically powered or electrically powered, or may be powered from axial or rotational forces transmitted to the actuator by a workstring. Some downhole actuators are powered by a pyrotechnic charge.
Various types of tools have been proposed for expanding a solid tubular downhole. Many of these tools utilize an expander which is moved axially through the tubular and is powered by hydraulic pressure in the tubular behind the expander. One of the problems with this technique is that the expanded tubular is inherently subject to high fluid pressure as the expander moves axially through the tubular. Leaks in the expanded tubular thus decrease the effectiveness of the technique, and the possibility of leaks reduces the recommended fluid pressure since there is a risk that a leak may prevent movement of the expander. If a leak prevents further movement of the expander, limited options are available to circumvent the problem, and the well may need to be abandoned.
Some tools have used hydraulically actuated expanders with fluid power being supplied to the actuator by a workstring separate from the tubular being expanded. As disclosed in U.S. Pat. Nos. 6,763,893, 6,814,143, 7,225,880, and 7,278,492, the actuator tool may include a series of pistons which move axially to move a tool mandrel with respect to an outer housing of the tool. The pistons are arranged hydraulically in a series, so that a significant axial force required for tubular expansion is obtained with conventional fluid pressure within the workstring and within the tool. By proper sizing, an actuator from 20 to 30 feet in length is able to generate high expansion forces over a stroke length of from 2 to 5 feet. If an additional length of tubular is to be expanded, the tool may be recocked and restroked a second or multiple times.
The disadvantages of the prior art are overcome by the present invention, in an improved actuator and a method of assembling the actuator as hereinafter disclosed.
SUMMARY OF THE INVENTIONIn one embodiment, a hydraulically powered downhole tool axially moves an expander in a well to radially expand a downhole tubular. A tool mandrel is axially secured to the expander, and a plurality of pistons are movable relative to the tool mandrel and are mechanically interconnected by an outer sleeve or housing of the tool radially exterior of the tool mandrel. One or more slips supported by the outer sleeve engage the interior wall of the well to temporarily fix an axial position of the outer sleeve in the well. Both the tool mandrel and the outer sleeve include a plurality of sections each having a lower end for interconnection with an upper end of another section. A retainer is provided for supporting each of the outer sleeve sections axially above a respective lower outer sleeve section, thereby exposing mandrel sections for assembly.
According to one embodiment of a method of the invention, the tool is assembled by supporting each of the outer sleeve sections axially above a respective lower sleeve section, thereafter assembling the exposed mandrel section, thereafter axially lowering the outer sleeve section over the mandrel, and thereafter assembling the outer sleeve section and respective lower sleeve section.
These and further features and advantages of the present invention will become apparent from the following detailed description, wherein reference is made to the figures in the accompanying drawings.
In various applications, expanders are used to radially expand a length of a downhole tubular so that, for example, the tubular is expanded from a run-in internal diameter of 6⅞ inch to an expanded internal diameter of 8.4 inches. Expansion of a downhole tubular may be desirable for a mono-bore well system, and may also be used to expand shorter lengths of a tubular for a seal patch, or for a liner hanger operation. In some mono-bore applications, a relatively short length of a tubular may be expanded by a hydraulically powered downhole tool, and thereafter a substantially longer length of the tubular is expanded by exerting an upward pull on the drill pipe workstring.
If the tubular being expanded is deep in the well, and particularly if the well has deviations which cause the workstring to engage the side of the well during an axial pulling operation, tubular expansion by pulling on the workstring may not be feasible. In other applications, the drilling rig or the workstring itself is not able to withstand the high pulling force that must be exerted on the expander to cause the desired tubular expansion.
According to the present invention, an improved actuator is provided for axially moving an expander a substantial axial distance of greater than about 1 meter during stroking of the hydraulic actuator. If the longer expansion of the tubular is required, the tool may be actuated, the tool moved and reset, and the actuator tool again stroked so that a combined length of expanded tubular may be more than 6 meters. Any desired longer length of tubular may be expanded by repeated stroking operations.
Referring now to
An intermediate portion of the tool as shown in
In
The running tool mandrel, the outer sleeve, and the pistons thus define variable size hydraulic cavities. A series of mandrel sections, outer sleeve sections, and inner and outer pistons may be provided in the hydraulic sections of the tool, so that axial forces effective stack to create a desired high expansion force. It is a particular feature of the invention that the tool as disclosed herein may generate a hydraulically generated axial force in excess of 1 million pounds, and preferably in excess of 1.5 million pounds, over a relatively long length of approximately 7 meters.
Slips 56 are prevented from moving downward due to engagement with sleeve 74. Collet mechanism 76 is provided between the OD of mandrel 20 and the ID of sleeve 74. Sleeve 74 thus includes suitable windows each for receiving a respective slip. Collet mechanism 76 may include upper and lower heads, and prevents the slips and sleeve 74 from moving downward with the outer sleeve 24 and slip housing 52 during the slip setting operation. The collets 76 are positioned about the mandrel 20 and releasably engage a groove or stop on the mandrel to hold the slips 54 in an upward position, so that the slips do not move downward while being set. The collets 76 may open radially outward after the slips are set, and allow the tool to be reset when the setting assembly is raised. The action of the collet mechanism is thus repeatable, thereby allowing the tool to be repeatedly stroked, recocked, and then restroked.
Keys 53 are provided in the slip housing 52 and cooperate axially between slips 56 and sleeve 74 to allow for rotation of sleeve 74 relative to slip housing 52. Keys 80 are also provided at the lower end of sleeve 74, and slide within axially extending slots or grooves 72 in the inner mandrel 20 to ensure rotation of the sleeve 74 relative to the mandrel 20. Thus, rotation applied to outer sleeve 24 is transmitted to mandrel 20. The slips may be set by dropping a ball on a seat 188 to raise the internal pressure within the mandrel 20 until the increased pressure forces the pistons axially apart, thereby generating a high axial force to set the slips and move the expander. Once the slips are set, the mandrel 20 may be moved upward relative to the slips during the tubing expansion operation.
A safety joint (not shown) with left-hand threads may allow for latching of the tool with the downhole expander at the lower end of the tool. Left-hand threads allow right-hand rotation of the workstring for drilling operations and, if necessary, left hand rotation to disengage the tool from the downhole expander. The upper half of the safety joint 173 is threaded to inner mandrel 72 and the safety joint lower half threaded at 172 to mandrel 170.
The lower end of tube 204, when positioned as shown in
Sleeve 174 threaded to mandrel 170 has lower clutch teeth 176 circumferentially arranged thereon. The clutch teeth 176 mate with and thus engage clutch teeth 177 at the upper end of mandrel 200. A radially external surface of the mandrel 200 includes axially extending splines 182, which mate with similar splines 180 on the modified liner section 178. The splines 180 on the liner section 178 similarly extend axially, and the upper and lower ends of the splines may include conventional tapers so that the mandrel 200 effectively slides along the splines while torque is transferred from the mandrel 170 to the mandrel 200, and from the mandrel 200 to the liner 12 to be subsequently expanded, thereby allowing the unexpanded liner and the tool to be rotated together as an assembly. High torque in the drill pipe workstring 14 and thus in the mandrel 20 may be transmitted radially outward from the inner mandrel to the tubular 12. The mandrel 170 includes a central bore 186, and a selectively sized seat 188 for subsequently receiving a ball or other plug member.
Mandrel 170 in turn is threaded at 192 to mandrel 190. When the tool is latched into the liner as shown in
Tube 204 may thus be threaded to and sealed to mandrel 190, and accordingly moves axially with mandrel 190. Expanding members 48 are supported adjacent the lower end of liner section 178, and may be threaded to the liner section as disclosed in U.S. application Ser. No. 11/803,389, hereby incorporated by reference. Lower housing 222 sandwiches the expander 48 between lower inwardly formed section 228 of the liner 212 and housing 222. For the embodiment depicted in
Housing 222 is threaded to the lower end of mandrel 200, and to the upper end of bit housing 224. Lower threads 220 on housing 224 are provided for conventionally receiving a bit or reamer 222 for drilling the hole in response to liner rotation. Tube 204 thus includes a central bore about axis 218 which supplies fluid to the bit 222. Tube 204 remains sealed to the housing 224 during axial movement of the tube.
To conduct a tubular drilling or reaming operation, the tool as shown in
The mandrel 200 which surrounds the lower end of mandrel 170 may be threaded at 216 to housing 222. Mandrel 190 is rotated with the mandrel 170, thereby also rotating tube 204. Torque may be transmitted from the mandrel 200 to the bit or reamer 222 without torque having to be transmitted through the expander 48.
After the liner 212 or other tubular drilling operation is complete, the drill pipe 12 may be picked up, thereby lifting the mandrel 170 and disengaging the clutch 175. Thereafter, the tool may be actuated, as explained above, so that the expander 48 is forced upward while the liner 12 remains held in place by slips 56, thereby expanding a length of the liner during an actuator stroking operation. As previously discussed, the slip resetting and stroking operation may be repeated until a desired length of the liner is expanded, after which time the liner is fixed at its lower end in the well, and an upward force on a drill pipe may be used to expand upper sections of the liner without stroking the tool.
The tool as disclosed herein may be recocked during an upward stroking operation, then the hydraulic section activated to set the slips and to pull up on the expander and expand a length of the tubular. The tool may be used to expand a tubular in an open hole operation, and may also be used to press a tubular tightly against the wall of another tubular in a cladding operation. Moreover, the technique is able to reliably expand overlapping joints of pipe sections which are expanded, thereby providing a monodiameter or continuous ID bore application.
The above application discloses elongate components, such as a tool mandrel and an outer sleeve exterior of the tool mandrel, which in practice are each a series of interconnected components, so the tool mandrel and the outer sleeve are each an assembly of a plurality of interconnected tool mandrel sections and a plurality of outer sleeve sections. Accordingly, each of these terms as used herein should be understood to include a plurality of sections which together form the elongate components.
Although specific embodiments of the invention have been described herein in some detail, this has been done solely for the purposes of explaining the various aspects of the invention, and is not intended to limit the scope of the invention as defined in the claims which follow. Those skilled in the art will understand that the embodiment shown and described is exemplary, and various other substitutions, alterations and modifications, including but not limited to those design alternatives specifically discussed herein, may be made in the practice of the invention without departing from its scope.
Claims
1. A hydraulically powered downhole tool for axially moving an expander in a well to radially expand a downhole tubular, comprising:
- a tool mandrel axially secured to the expander, the tool mandrel including a plurality of mandrel sections each having a lower end for interconnection with an upper end of another tool mandrel section;
- a plurality of pistons each axially movable relative to the tool mandrel and mechanically interconnected by an outer sleeve exterior of the tool mandrel;
- one or more slips supported by the outer sleeve to temporarily fix an axial position of the outer sleeve in the well;
- the outer sleeve including the plurality of outer sleeve sections each having a lower end for interconnection to an upper end of another outer sleeve section; and
- a retainer for supporting an upper outer sleeve section axially above a lower outer sleeve section, thereby exposing upper and lower mandrel sections for assembly, the upper outer sleeve section being axially lowered over the assembled upper and lower mandrel sections for connection with the lower outer sleeve section.
2. A downhole tool as defined in claim 1, wherein hydraulic fluid is supplied to the plurality of pistons through a workstring having an interior in fluid communication with an interior bore in the tool mandrel.
3. A downhole tool as defined in claim 1, wherein the one or more slips include a plurality of circumferentially spaced slips for engaging an inner wall of the downhole tubular in the well.
4. A downhole tool as defined in claim 1, further comprising:
- another plurality of pistons each axially movable relative to the outer sleeve and mechanically interconnected to the tool mandrel.
5. A downhole tool as defined in claim 1, wherein the tool mandrel includes upper and lower sections interconnected by a threaded pin and box connection.
6. A downhole tool as defined in claim 1, wherein the outer sleeve includes upper and lower sections interconnected by a threaded connection.
7. A downhole tool as defined in claim 1, wherein the retainer comprises threads secured to the mandrel; and
- through ports in the mandrel supply fluid pressure to the plurality of pistons.
8. A downhole tool as defined in claim 1, wherein each of the one or more slips and the outer sleeve include cam portions to force the slips radially outward in response to axial movement of the tool mandrel relative to the outer sleeve.
9. A downhole tool as defined in claim 1, wherein the tool is assembled with a substantially vertical assembly axis at a well site.
10. A hydraulically powered downhole tool comprising:
- a tool mandrel having an interior bore;
- a plurality of pistons each axially movable relative to the tool mandrel and mechanically interconnected by an outer sleeve exterior of the tool mandrel;
- another plurality of pistons each axially movable relative to the outer sleeve and mechanically interconnected to the tool mandrel;
- a work string supplying hydraulic fluid to the plurality of pistons and the another plurality of pistons through an interior of the work string in fluid communication with the interior bore in the tool mandrel;
- the tool mandrel including a plurality of mandrel sections each having a lower end for interconnection with an upper end of another tool mandrel section;
- the outer sleeve including the plurality of outer sleeve sections each having a lower end for interconnection to an upper end of another outer sleeve section; and
- a retainer for supporting an upper outer sleeve section axially above a respective lower outer sleeve section, thereby exposing upper and lower mandrel sections for assembly, the upper outer sleeve section being axially lowered over the assembled upper and lower mandrel sections connection with the respective lower outer sleeve section.
11. A downhole tool as defined in claim 10, wherein the tool mandrel includes upper and lower sections interconnected by a threaded pin and box connection.
12. A downhole tool as defined in claim 10, wherein the outer sleeve includes upper and lower sections interconnected by a threaded connection.
13. A downhole tool as defined in claim 10, wherein the retainer comprises a latch to temporarily secure an axial position of an outer sleeve section with respect to the tool mandrel.
14. A downhole tool as defined in claim 10, wherein through ports in the mandrel supply fluid pressure to the plurality of pistons.
15. A downhole tool as defined in claim 10, further comprising:
- a plurality of circumferentially spaced slips supported by the outer sleeve for engaging the downhole tubular in the well to temporarily fix an axial position of the outer sleeve in the well.
16. A method of assembling a hydraulically powered downhole tool at a well site, comprising:
- providing a tool mandrel having an interior bore;
- providing a plurality of pistons each axially movable relative to the tool mandrel and mechanically interconnected by an outer sleeve exterior of the tool mandrel;
- the tool mandrel including a plurality of mandrel sections each having a lower end for interconnection with an upper end of another tool mandrel section;
- the outer sleeve including a plurality of outer upper sleeve sections each having a lower end for interconnection to an upper end of an outer lower sleeve section;
- temporarily supporting each of the outer sleeve sections axially above a respective lower outer sleeve section;
- thereafter interconnecting two mandrel section;
- thereafter axially lowering the outer sleeve section over the interconnected mandrel section; and
- thereafter assembling the outer sleeve section and the outer lower sleeve section.
17. A method as defined in claim 16, further comprising:
- supplying hydraulic fluid to the plurality of pistons through a workstring having an interior in fluid communication with the interior bore in the tool mandrel.
18. A method as defined in claim 16, wherein the tool mandrel includes upper and lower sections interconnected by a threaded pin and box connection.
19. A method as defined in claim 16, wherein threads on an exterior surface of the mandrel temporarily supports a respective outer sleeve section.
20. A method as defined in claim 16, further comprising:
- supporting one or more slips on the outer sleeve to temporarily fix an axial position of the outer sleeve in the well.
Type: Application
Filed: Dec 23, 2008
Publication Date: Jun 24, 2010
Inventor: Britt O. Braddick (Harris County, TX)
Application Number: 12/342,849
International Classification: E21B 23/08 (20060101); E21B 43/10 (20060101); B21D 41/02 (20060101); E21B 23/04 (20060101);