Patent Application
20250137337
Packers are downhole tools used in the oilfield to isolate one wellbore region from another. Generally, the packers are lowered and set in the well using a drill pipe string. Once the packer is set, the landing string is released from the packer and the landing string is then withdrawn. There are a variety of different types of packers. One specific type of packer is a storm packer. Storm packers are typically used in offshore drilling to pack off an upper section of a well from a lower section, while supporting a drill string (“tailpipe”) extending farther down into the well. By contrast, most retrievable packers/plugs are not configured to support a tailpipe. Using the storm packer, when inclement weather (hence the name “storm packer”) is approaching, or it is otherwise desirable to temporarily abandon a well, the well can be plugged and surface equipment moved without pulling the entire drill string from the well. In at least some jurisdictions, regulatory authorities may require offshore drilling rigs to have a storm packer available for such situations.
Packers which are mechanically activated currently employ permanent or temporary reversible lock segments which thread to engage or unthread to disengage if temporary. In the case of reversible temporary lock segments becoming stuck, the only current solution is to mill out the stuck packer, and retrieve it with fishing equipment. This method time-consuming and costly and comes with several risks.
A downhole tool is disclosed. The downhole tool includes an inner mandrel including external threads. The downhole tool also includes a lock ring positioned around the inner mandrel. The lock ring includes a plurality of segments that are circumferentially-offset from one another. The segments are configured to separate from one another in response to a radially-outward force. Each segment includes an inner lock segment portion including internal threads that are configured to engage the external threads of the inner mandrel. Each segment also includes an outer lock segment portion that is positioned radially-outward from the inner lock segment portion. Each segment also includes a plurality of shear elements extending at least partially radially-through the inner lock segment portion and the outer lock segment portion to couple the inner lock segment portion and the outer lock segment portion together. The shear elements are configured to shear in response to a predetermined force to decouple the inner lock segment portion from the outer lock segment portion.
A method for withdrawing a downhole tool from a well is also disclosed. The method includes moving an inner mandrel of the downhole tool in a downhole direction toward a lock ring of the downhole tool. The lock ring is positioned around the inner mandrel. The method also includes engaging external threads of the inner mandrel with internal threads of the lower lock ring. The method also includes determining that the downhole tool is stuck in the well. The method also includes exerting a predetermined force on the lock ring in response to determining that the downhole tool is stuck in the well, which causes a shear element in the lock ring to shear, thereby decoupling an inner lock segment portion of the lock ring from an outer lock segment portion of the lock ring. The inner lock segment portion includes the internal threads. The outer lock segment portion is positioned radially-outward from the inner lock segment portion.
A method for withdrawing an anchor-packer assembly from a well is also disclosed. The method includes running the anchor-packer assembly into the well. The anchor-packer assembly includes a packer having a packer slips assembly and a seal. The packer slips assembly and the seal are radially-expandable so as to engage a surrounding tubular. The anchor-packer assembly also includes an anchor coupled to and positioned above the packer. The anchor is configured to set the packer. The anchor includes an inner mandrel including external threads. The anchor also includes a lock ring positioned around the inner mandrel. The lock ring includes a plurality of segments that are circumferentially-offset from one another. The segments are configured to separate from one another in response to a radially-outward force. Each segment includes an inner lock segment portion including internal threads that are configured to engage the external threads of the inner mandrel. Each segment also includes an outer lock segment portion that is positioned radially-outward from the inner lock segment portion. Each segment also includes a plurality of shear elements extending at least partially radially-through the inner lock segment portion and the outer lock segment portion to couple the inner lock segment portion and the outer lock segment portion together. The shear elements are configured to shear in response to a predetermined force to decouple the inner lock segment portion from the outer lock segment portion. The method also includes moving the inner mandrel in a downhole direction toward the lock ring. The method also includes engaging the external threads of the inner mandrel with the internal threads of the lower lock ring. The method also includes determining that the anchor-packer assembly is stuck in the well. Determining that the anchor-packer assembly is stuck in the well comprises determining that the anchor cannot be unset by unscrewing the inner mandrel from the lock ring. Unscrewing the inner mandrel from the lock ring is part of a primary way to retract a slips assembly of the anchor. The method also includes exerting a predetermined force on the lock ring in response to determining that the anchor-packer assembly is stuck in the well, which causes the shear elements to shear, thereby decoupling the inner lock segment portion from the outer lock segment portion. The inner lock segment portion is configured to move in an uphole direction through an annulus formed around the inner mandrel after the shear elements shear. The outer lock segment portion remains in a recess formed in an outer mandrel of the anchor once the shear elements shear. Exerting the predetermined force is part of a secondary way to retract the slips assembly. The secondary way is only performed in response to determining that the anchor cannot be unset by unscrewing the inner mandrel from the lock ring. The method also includes moving the inner mandrel and the inner lock segment portion in the uphole direction with respect to the outer lock segment portion after the shear elements shear, which causes the slips assembly to retract. The method also includes withdrawing the anchor-packer assembly from the well after the slips assembly retracts.
The foregoing summary is intended merely to introduce a subset of the features more fully described of the following detailed description. Accordingly, this summary should not be considered limiting.
The accompanying drawing, which is incorporated in and constitutes a part of this specification, illustrates an embodiment of the present teachings and together with the description, serves to explain the principles of the present teachings. In the figures:
It should be noted that some details of the figure have been simplified and are drawn to facilitate understanding of the embodiments rather than to maintain strict structural accuracy, detail, and scale.
Reference will now be made in detail to embodiments of the present teachings, examples of which are illustrated in the accompanying drawing. In the drawings, like reference numerals have been used throughout to designate identical elements, where convenient. The following description is merely a representative example of such teachings.
A slips assembly 207 may also be positioned around the inner mandrel 202. The slips assembly 207 may include a first cone 208, a second cone 210, and one or more slips 212. The slips assembly 207 may also include a cage 214 that connects to and extends between the first and second cones 208, 210. The cage 214 also extends over the slips 212 and provides windows through which the slips 212 may extend radially outward. The slips 212 may be driven radially outward by moving the cones 208, 210 axially closer together, e.g., by moving one or both cones 208, 210 relative to the inner mandrel 202 and the slips 212.
In an embodiment, the first cone 208 may be positioned axially against an end of the upper sub 204. A cover 216 may be provided over an interface between first cone 208 and the upper sub 204 and may be secured against movement in at least one direction by connection to the upper sub 204. The first cone 208 may be prevented from moving relative to the inner mandrel 202 via engagement with the upper sub 204 and the cover 216 and/or by direct fastening thereof to the inner mandrel 202. In the illustrated anchor running position, the slips 212 are retracted radially inward, and are held generally within the cage 214, near the inner mandrel 202. Upon actuation to an anchor set position the slips 212 may extend radially outwards so as to engage with and anchor in a surrounding tubular.
The anchor 200 also includes a lower sub 218 that is received around a lower portion of the inner mandrel 202. The lower sub 218 may not be secured directly to the inner mandrel 202; rather, the inner mandrel 202 may be configured to rotate and/or axially translate relative to the lower sub 218 so as to actuate the anchor 200. The lower sub 218 may also provide a lower connection 220, which may be a threaded, male “pin end” connection that is configured to be connected directly to the packer 300. Thus, the connection between the lower sub 218 and the packer 300 may be configured to transmit axial loads and torque therebetween, which may permit the anchor 200 not only to set the packer 300 in the well, but also to use the packer 300 to set the anchor 200, as will be described in greater detail below.
The anchor 200 also includes a torque mandrel 224 that is secured to the lower sub 218 such that the torque mandrel 224 and the lower sub 218 are not rotatable or axially movable relative to one another. For example, the torque mandrel 224 may be threaded, fastened, or otherwise secured to the lower sub 218. In some embodiments, the torque mandrel 224 may be integral to the lower sub 218.
A setting control assembly 222 may be positioned between the upper sub 204 and the lower sub 218. The setting control assembly 222 may be configured to selectively transfer torque, applied at the upper sub 204 to the lower sub 218, and to the packer 300, to facilitate rotating a portion of the packer 300 to unlock and set the slips thereof, as will be described in greater detail below. Once the packer slips are set, the setting control assembly 222 may allow for differential rotation of the upper sub 204 and inner mandrel 202 relative to the lower sub 218 of the anchor 200 and the packer 300, which may permit selectively setting the anchor 200 in the well.
In an embodiment, the setting control assembly 222 includes a lower lock ring 226 that may be positioned in a groove formed between the inner shoulders of the torque mandrel 224 and the lower sub 218 when the outer shoulders of the torque mandrel 224 and lower sub 218 are abutted against each other. For example, as shown, the torque mandrel 224 may overlap the lower sub 218, such that the torque mandrel 224 not only axially abuts the lower lock ring 226, but also extends over and entrains the lower lock ring 226 radially between the torque mandrel 224 and the inner mandrel 202. When the anchor 200 is in the set position, the lower lock ring 226 engages threads of the inner mandrel 202, as will be described in greater detail below. Axial movement of the inner mandrel 202 in at least one axial direction (e.g., both directions) relative to the lower lock ring 226 is prevented (e.g., only rotation is permitted) while the anchor 200 is in the running position by engagement between the upper lock ring 232 and mating threads on the inner mandrel 202. In the illustrated anchor running position, the lower lock ring 226 may not engage threads of the inner mandrel 202, but may be axially offset therefrom, which permits such sliding axial movement required to set the anchor in the wellbore.
The setting control assembly 222 may further include a clutch connector 230 which may be received around the inner mandrel 202. The clutch connector 230 may be rotationally secured to the inner mandrel 202, such that the clutch connector 230 is constrained from rotating with respect thereto. The connection between the clutch connector 230 and the inner mandrel 202 may, however, permit the inner mandrel 202 to slide or “shift” axially by a distance with respect to the clutch connector 230. For example, the clutch connector 230 may be secured to the inner mandrel 202 via one or more keys, pins, blocks, etc., which may be received into corresponding axially-extending grooves (not visible in this view) formed in the inner mandrel 202. Additionally or alternatively, the keys, blocks, etc., may be formed in or connected to the inner mandrel 202 and received into corresponding grooves in the clutch connector 230. Since the inner mandrel 202 and the clutch connector 230 are rotationally locked together, torque applied to the inner mandrel 202 (via the upper sub 204) is transmitted to the clutch connector 230.
An upper lock ring 232 of the setting control assembly 222 may be disposed axially adjacent to at least a portion of the clutch connector 230. Like the lower lock ring 226, the upper lock ring 232 may be configured to engage an upper set of threads formed in the inner mandrel 202. Further, a cone connector 234 may be coupled with the clutch connector 230, which may entrain the upper lock ring 232 axially within a groove formed between the cone connector 234 and the clutch connector 230, and radially between the inner mandrel 202 and the cone connector 234. In the illustrated anchor running position, the upper lock ring 232 may engage threads of the inner mandrel 202, such that the inner mandrel 202 is prevented from sliding relative to the clutch connector 230 in at least one axial direction. Accordingly, the combination of the lock rings 226, 232 and the components that interact therewith in the anchor 200 form an embodiment of a “locking mechanism”, as they may be configured to selectively restrain the anchor 200. In other embodiments, one or more of these components may be omitted or other components added in order to perform the function of the locking mechanism. In this embodiment, the upper lock ring 232 restrains the anchor 200 in the running position, and the lower lock ring 226 restrains the anchor 200 in the set position, as will be described in greater detail below. Additionally, the term “selectively” refers to something done at the selection of the designer and/or the operator, and not conducted incidentally. For example, the locking mechanism may “selectively” restrain (or permit movement of) the anchor 200 depending on the operations conducted by the intentional operations of the operator.
The setting control assembly 222 may also include a clutch 240, which may be configured to selectively prevent or permit relative rotation between the inner mandrel 202 and the components positioned around the inner mandrel 202 that are non-rotatable relative to the lower sub 218. For example, the clutch 240 may prevent rotation between the inner mandrel 202 and the torque mandrel 224, unless a predetermined amount of torque is applied. When the packer 300 is not set, this predetermined amount of torque may not be experienced, because the packer 300 may be generally permitted to rotate in the wellbore, as will be described in greater detail below. In other words, rotating the inner mandrel 202 may cause the lower sub 218 that is connected to the packer 300 to rotate unless there is a resistance to such rotation that requires at least a predetermined amount of torque to overcome. When such resistance is present, the clutch 240 does not transmit additional torque, but instead permits the inner mandrel 202 to rotate relative to the lower sub 218 (and the packer 300).
In an embodiment, the clutch 240 includes an upper clutch jaw 242 that is coupled to the clutch connector 230 and rotationally locked to the inner mandrel 202. The clutch 240 also includes a lower clutch jaw 244 that meshes with the upper clutch jaw 242 and is rotationally locked to the torque mandrel 224, which is in turn rotationally locked to the lower sub 218. The upper and lower clutch jaws 242, 244 are biased into engagement by a biasing member 246, e.g., a spring. In the illustrated embodiment, the biasing member 246 is positioned axially between the torque mandrel 224 and the lower clutch jaw 244, thereby biasing the lower clutch jaw 244 into torque-transmitting connection with the upper clutch jaw 242; however, it will be appreciated that the biasing member 246 could be configured to apply a biasing force on the upper clutch jaw 242. A clutch cover 248 may extend between the torque mandrel 224 and the clutch connector 230 and may cover the upper and lower clutch jaws 242, 244 and the biasing members 246, while permitting relative rotation of the clutch connector 230 and the torque mandrel 224.
The inner mandrel 202 has upper threads 250 and lower threads 252. The upper and lower threads 250, 252 may be configured to be threaded into the upper and lower lock rings 232, 226 respectively, by rotating the inner mandrel 202 relative thereto. Further, as shown, the upper lock ring 232 may be formed from a plurality of arcuate segments 254, which may be held together, end-to-end to form an annular structure that extends around the inner mandrel 202. The arcuate segments 254 may be held together via one or more springs, which may be received into circumferential grooves 256, 258 formed in the segments 254. The lower lock ring 226 may be similarly formed from segments 260, with springs received into grooves 262, 263 holding the segments 260 together around the inner mandrel 202. Accordingly, the thread form on the lock rings 232, 226 and inner mandrel 202 may be configured to allow for “jumping” the respective threads 250, 252, as the segments 254, 260 thereof separate apart, such that each permits axial sliding (i.e., without requiring rotation) movement of the inner mandrel 202 in one axial direction. In an embodiment, the lock rings 232, 226 may be configured to permit axial movement of the inner mandrel 202 in opposite directions, while each resists movement in the opposite direction, when engaged with the threads 250 or 252. The helical orientation of the threads 250, 252 may also be reversed, such that selective rotation of the inner mandrel 202 in the same rotational direction (e.g., right-hand rotation) causes the lock rings 232, 226 to disengage from the threads 250, 252 in opposite axial directions.
When the anchor 202 is released from the set position in the wellbore the upper sub 204 and inner mandrel 202 are lowered relative to the clutch connector 230, torque mandrel 224 and lower sub 218. As the inner mandrel 202 is lowered, the segments of the upper lock ring 232 are ratcheted radially outward over the upper threads 250 without rotation of either the inner mandrel and the upper lock ring 232. The anchor 200 is retained in the running position by way of reengagement between the upper threads 250 and the upper lock ring 232. This action resets the anchor 200 to the running position, which allows the anchor and anchor-packer assembly 100 to be withdrawn from the wellbore.
It will be appreciated that the positioning of the lower lock ring 232 may be swapped with the upper lock ring 232, along with swapping the orientation of the threads 250, 252, without departing from the scope of the present disclosure. Moreover, the upper and lower lock rings 226, 232 may be on a same axial side of the clutch 240. In other embodiments, other connections that permit rotation but control (e.g., selectively permit and block) axial translation of the inner mandrel 202 may be employed.
Referring again to
Accordingly, teeth of the lower clutch jaw 244 may be permitted to momentarily back out of engagement with complementary wedge-shaped teeth of the upper clutch jaw 242, by application of a torque from the inner mandrel 202 to the upper clutch jaw 242 that is above a predetermined amount of torque (e.g., predetermined torque threshold). This clutch arrangement allows torque below the predetermined torque threshold to be transmitted from the inner mandrel 202 and upper clutch jaw 242 to the lower clutch jaw 244, torque mandrel 224, the lower sub 218 and the packer 300 below. Once the packer 300 is set and rotationally secured into engagement with the wellbore the upper sub 204, clutch connector 230, and inner mandrel 202 are allowed to rotate relative to the torque mandrel 224 and lower sub 218 via the ratcheting action of the lower clutch jaw 242. It will be appreciated that other clutch 240 designs, configured to transmit torque up to a certain predetermined torque setting may be employed, without departing from the scope of the present disclosure.
The packer 300 may further include a hold down mandrel 306, including hold down buttons 308 and straps 310, which will be described in greater detail below. A packer mandrel 312 may extend from the hold down mandrel 306, and may be coupled thereto such that the packer mandrel 312 rotates with the mandrel 306, which is rotated by torque applied to the upper sub 302. The torque mandrel 224 (
A slips assembly 316 may also be positioned around the packer mandrel 312. The slips assembly 316 may include a plurality of (e.g., unidirectional) slips 317, which may, on one axial side, engage a tapered cone 318. Thus, when the slips assembly 316 is axially compressed, e.g., by pressing or allowing the packer mandrel 312 to move downwards with respect thereto, the slips assembly 316 may expand radially outward by driving the cone 318 downward relative to slips 317.
Once the slips 317 are anchored into the surrounding tubular, and the sealing element 314 is in sealing position (the packer 300 is set), the hold down buttons 308 are hydraulically pressed radially outward into a gripping engagement with the surrounding tubular when a differential between the pressure from below the packer 300 is greater than the pressure from above the packer 300. The hold down buttons 308 may have angled teeth, and the teeth of the slips 317 are angled in an opposite direction. Thus, when the buttons 308 are pressed outward, the combination of the slips 317 and the buttons 308 may prevent an upward force from below the packer 300 dislodging the packer 300 from its set position.
Drag blocks 320 may be positioned below the slips assembly 316 and around the packer mandrel 312. The drag blocks 320 are configured to bear against the surrounding tubular, so as to provide friction therewith that resists movement and permits the packer mandrel 312 to be moved relative thereto. Further, a control body 322 may be positioned below and coupled to (e.g., secured in position relative to) the drag blocks 320. A J-pin retainer 323 may be secured to a lower end of the control body 322.
The control body 322 and the J-pin retainer 323 may thus be movable relative to the packer mandrel 312, e.g., to set the packer 300. For example,
Combined operation of the anchor 200 and the packer 300 can be understood in view of the foregoing description of the components and the following discussion. In particular,
The method 800 may include connecting the anchor 200 to the packer 300, as at 802. The anchor 200 may, for example, be connected to the top of the packer 300 by threading the lower connection 220 into the upper connection 304 of the packer 300, such that a tubular string that runs the assembly 100 into the well is connected to the anchor 200 and not directly to the packer 300. In some embodiments, the packer 300 may be configured to be connected at its lower end to a tailpipe, but may not be connected to such tailpipe. In other embodiments, a tailpipe may be present. The anchor 200 may then be connected to a tubular string, as at 804, and the anchor-packer assembly 100 may be deployed (“run”) into a well, as at 806. Eventually the anchor-packer assembly 100 may reach a location where the anchor-packer assembly 100 is to be set.
Referring to
As noted above and shown in
Upon the anchor-packer assembly 100 reaching the desired setting location, the method 800 may include rotating the packer mandrel 312 by rotating the tubular string and the anchor 200 through transmission of a first torque, as at 808. This first torque received at the anchor 200 from the tubular string is transmitted through the inner mandrel 202 to the clutch 240. The lower sub 218 is able to rotate along with the inner mandrel 202 by torque transmission through the clutch 240. The drag blocks 320 of the packer 300 resist this rotation, but do not react a torque greater than the predetermined torque setting of the clutch 240. Accordingly, the lower sub 218, and thus the packer mandrel 312 rotate relative to the control body 322, thereby moving the pin 324 into the axially-extending portion of the J-slot 326.
Next, as at 810, the slips 317 and seals 314 of the packer 300 are set by applying a downward force (weight) to the anchor 200 via the tubular string, e.g., a “first” axial force. The downward force is applied to the inner mandrel 202 via the upper sub 204. As noted above, the locking mechanism is in the first locked condition, with the upper lock ring 232 transmitting downward axial force from the inner mandrel 202 to the clutch connector 230, the torque mandrel 224 and the lower sub 218. Thus, this downward axial force is transmitted to the packer mandrel 312. The drag blocks 320 resist the axial movement, and as a result, the packer mandrel 312 moves downward relative to the control body 322, thereby moving the pin 324 in the axially-extending portion of the J-slot 326, and expanding the slips assembly 316 and the seals 314. The packer 300 is now set (i.e., actuated into the packer set position).
The packer 300 however, as mentioned above, may be a storm packer, and thus may be designed to stay in the packer set position under downward axial load on its packer mandrel 312 provided by the tailpipe. In the absence of a tailpipe (e.g., when the packer 300 is being used as a retrievable plug and is connected to the anchor 200), the packer 300 may not include any devices that, independently of the anchor 200, are configured to prevent the packer mandrel 312 from rising in the well, e.g., due to a transient pressure differential, and releasing the slips 317. The anchor 200, however, provides this functionality.
At this point, the anchor 200 remains in the anchor running position, with its locking mechanism in the first locked condition. Specifically, the upper lock ring 232 is engaging the upper threads 250 and preventing downward movement of the inner mandrel 202.
Accordingly, the method 800 may include, as at 812, rotating (e.g., a “second” torque) the tubular string so as to rotate the upper portion of the anchor 200 relative to the packer 300. The direction of rotation may remain the same, e.g., right-handed, so as to preserve integrity of the threaded connections in the tubular string and in the anchor-packer assembly 100. This second torque is applied to the upper sub 204 of the anchor 200, and is transmitted to the inner mandrel 202. The packer 300, which is set as noted above and has its pin 324 is in the axially-extending portion of the J-slot 326, thus resists rotation relative to the wellbore. The torque applied to the inner mandrel 202 is applied to the upper clutch jaw 242 of the clutch 240, but the lower clutch jaw 244 is rotationally locked to the lower sub 218 and thus the packer mandrel 312, which is prevented from rotating because the packer 300 is set. Once the torque applied to the inner mandrel 202 reaches the predetermined torque setting of the clutch 240, the upper clutch jaw 242 rotates relative to the lower clutch jaw 244, permitting the inner mandrel 202 to rotate relative to the upper lock ring 232 in the first rotational direction. Continued rotation results in the upper threads 250 becoming unmeshed from the threads 266 of the upper lock ring 232, which unlocks or “releases” the locking mechanism of the anchor 200. In other words, the anchor 200 is now in the unlocked condition, as the inner mandrel 202 may be permitted to move axially downward from its position in the anchor set position.
The method 800 may then include setting the slips 212 of the anchor 200 by lowering the inner mandrel 202 axially in the first axial direction (downhole), e.g., by moving the tubular string in the first axial (downhole) direction (e.g., via application of a “second” axial force), as at 814. The upper cone 208 may not be axially movable with respect to the inner mandrel 202, and thus is also moved downward. In contrast, the slips 212 and lower cone 210 may be axially stationary relative to the lower sub 218. Thus, moving the inner mandrel 202 in a downhole direction moves the upper cone 208 toward the lower cone 210 and drives the slips 212 radially outward and into engagement with (e.g., so as to partially embed or “bite into”) the surrounding tubular.
This axial movement of the inner mandrel 202 may also move the locking mechanism into a second locked condition, i.e., the axial movement “locks” the previously unlocked/released locking mechanism. In particular, as shown in
With the mandrel 202 locked in place relative to the lower sub 218, the packer 300 is thus likewise locked in its packer set configuration. That is, the packer mandrel 312 is at least axially fixed in position relative to the lower sub 218 of the anchor 200. The lower sub 218 is prevented from moving axially in the uphole direction, because it is axially engaged with the slips assembly 207. To permit the lower sub 218 to move in an uphole direction, the slips assembly 207 either needs to compress or release. However, compressing the slips assembly 207 would cause the slips 212 to move outward, and the slips 212 are already engaging the surrounding tubular and thus cannot move outward. Moving the inner mandrel 202 in the uphole direction relative to the lower sub 218, which would retract the slips 212, is prevented by the lower lock ring 226 engaging the threads 252 of the inner mandrel 202. Thus, the lower sub 218 is locked in axial position by the slips assembly 207, thereby locking the packer 300 in its packer set configuration. Once the packer is set in the wellbore the landing string may be disconnected and retrieved from the wellbore. The packer 300 and anchor assembly 200 may then be considered set and the well therefore plugged. The packer 300 may retain its position in the well indefinitely. This is accomplished, as described above, through selective rotation and axial movement of the anchor 200 and/or packer 300.
At some point, it may be desired to retrieve the packer 300 from the well. Thus, the method 800 may include selectively rotating the inner mandrel 202, e.g., using the tubular string connected to the upper sub 204 of the anchor 200, so as to release the locking mechanism, as at 820. This rotation may continue to be in the same, right-hand orientation. Since the packer 300 is still set and resisting rotation, the clutch 240 permits the inner mandrel 202 to rotate relative to the lower sub 218, and thus relative to the lower lock ring 226. The rotation of the inner mandrel 202 may advance the threads 252 progressively out of engagement with the lower lock ring 226, and the mandrel 202 may be rotated until the threads 252 are fully disengaged from the lower lock ring 226. This unlocks (releases) the locking mechanism from its second locked condition.
The slips 212 may then be retracted, as at 822, by selectively moving/sliding the inner mandrel 202 and upper sub 204 axially in the second axial direction (uphole), which may permit the upper cone 208 to move away from the lower cone 210. The threads 250 of the inner mandrel 202 may be moved axially into engagement with the threads 266 of the upper lock ring 232, which permit such uphole movement but resist axial sliding movement of the inner mandrel 202 in the first axial (downhole) direction relative to the lower sub 218. Thus, the locking mechanism is once again locked, this time back in the first locked condition, and the anchor 200 is back in the anchor running position.
The method 800 may then include retracting the slips 317 and seals 314 of the packer 300 by selectively applying an upward force in the second axial direction (uphole) to the anchor 200, as at 824. This force is transmitted to the lower sub 218 via the inner mandrel 202, and the threads 250 thereof in connection with the upper lock ring 232. Since the anchor 200 is in the anchor running configuration, and is not anchored in place against the surrounding tubular, the force on the lower sub 218 is applied to the packer mandrel 312. The packer mandrel 312 thus moves relative to the pin 324, such that the pin 324 is moved back into the circumferentially-extending portion of the J-slot 326. This also retracts the slips 317 and permits the seals 314 to resiliently retract radially inward. The packer 300 is thus unset, although the drag blocks 320 still engage the surrounding tubular.
The method 800 then includes selectively rotating the packer mandrel 312 by selectively rotating the upper sub 204 of the anchor 200, as at 826. Because the packer 300 is no longer set, the resistance to rotation between the inner mandrel 202 and the lower sub 218 may not exceed the predetermined torque setting of the clutch 240. As a result, the rotation is transferred to the packer mandrel 312, which moves the pin 324 in the circumferentially-extending portion of the J-slot 326, back to its original position. The packer 300 is now back in the packer running position, and, because the anchor 200 has already been returned to the anchor running position, the assembly 100 may be removed from the well, e.g., by moving the anchor-packer assembly 100 in the second axial direction (uphole), as at 828.
In one embodiment, each lock segment 260 may include a first (e.g., inner) lock segment portion 910 and a second (e.g., outer) lock segment portion 920. The inner lock segment portions 910 may be positioned radially-inward from the outer lock segment portions 920 with respect to a central longitudinal axis through the lower lock ring 226. The inner lock segment portions 910 may include or define (e.g., buttress) threads 912 that are configured to engage the lower threads 252 on the inner mandrel 202, as described below.
The lower lock ring 226 may also include a plurality of shear elements 930 that are circumferentially-offset from one another. The shear elements 930 may be or include shear pins or shear screws. The shear elements 930 may extend at least partially radially-through the inner lock segment portions 910 and the outer lock segment portions 920. The shear elements 930 may be configured to couple the inner lock segment portions 910 and the outer lock segment portions 920 together (e.g., before shearing).
The shear elements 930 may be configured to shear when exposed to a predetermined (e.g., axial and/or rotational) force. For example, the shear elements 930 may be configured to shear in response to the inner mandrel 202 being pulled in the uphole direction, which exerts the predetermined axial force on the shear elements 930. Once sheared, the inner lock segment portions 910 and the outer lock segment portions 920 may no longer be coupled together and may thus be able to move (e.g., axially and/or rotationally) with respect to one another. More particularly, the inner mandrel 202 and the inner lock segment portions 910 may move in the uphole direction with respect to the outer lock segment portions 920. This may retract the slips 212 of the anchor 200. Once the slips 212 are retracted, the packer 300 may be unset and/or actuated back into the packer running position. The anchor-packer assembly 100 may then be removed from the casing and/or well. In addition to being implemented into the anchor-packer assembly 100, the shearable locking mechanism (e.g., lower lock ring 226 with the shear elements 930) can also or instead be implemented into a packer or retrievable bridge plug (e.g., which may not be connected to an anchor).
The lower lock ring 226 may also include a plurality of key segments 940 that are circumferentially-offset from one another. The key segments 940 may protrude radially-outward from the outer surfaces of the lock segments 260. In the embodiment shown, each lock segment 260 may include one key segment 940 positioned circumferentially-between two pairs of shear elements 930. The key segments 940 may be configured to engage with an outer tubular member (e.g., the lower sub 218 and/or the torque mandrel 224). This engagement may prevent the lower lock ring 226 from rotating and/or moving axially with respect to the outer tubular member.
As described above, the lower lock ring 226 may also include or define one or more circumferential grooves (two are shown: 262, 263). The grooves 262, 263 may be axially-offset from one another. An (e.g., elastomeric) O-ring 264, 265 may be positioned in each groove 262, 263.
The method 1000 may be performed in response to at least a portion of the anchor-packer assembly 100 (e.g., the anchor 200) becoming stuck in the well such that it is unable to be unset and/or withdrawn using the method 800 (e.g., steps 820-828). More particularly, the method 1000 (e.g., including shearing the shear elements 930) may be a backup/secondary option for withdrawing the anchor-packer assembly 100 from the well in the event that the primary option (e.g., method 800) cannot withdraw the anchor-packer assembly 100 from the well. An illustrative order of the method 1000 is provided below; however, one or more steps of the method 1000 may be performed in a different order, simultaneously, repeated, or omitted.
In one embodiment, the method 1000 may begin after step 812 (e.g., and/or before step 820) of the method 800, which is described above with reference to
The method 1000 may thus begin by moving the inner mandrel 202 axially in the downhole direction, as at 1010. This is shown in
The method 1000 may also include engaging the inner mandrel 202 with the lower lock ring 226, as at 1020. This is shown in
The method 1000 may also include determining that the anchor-packer assembly 100 (e.g., the anchor 200) is stuck in the well, as at 1030. As used herein, the term “stuck” refers to an inability to unlock and/or unset at least a portion of the anchor-packer assembly 100 and/or an inability to retrieve/withdraw a portion of the anchor-packer assembly 100 from the well. In one embodiment, this may include determining that the locking mechanism cannot be unlocked (step 820). In another embodiment, this may include determining that the anchor 200 cannot be actuated back in the anchor running position (step 822). In another embodiment, this may include determining that the packer 300 cannot be unset (step 824). In another embodiment, this may include determining that the packer 300 cannot be actuated back in the packer running position (step 826). In another embodiment, this may include determining that the anchor-packer assembly 100 cannot be moved in the uphole direction and/or be removed from the well (step 828).
The method 1000 may also include exerting a predetermined force on the lower lock ring 226, as at 1040. More particularly, the inner mandrel 202 may be pulled in the second (e.g., uphole) axial direction, which may exert the predetermined force on the lower lock ring 226. As the inner mandrel 202 is now engaged with the inner lock segment portions 910, the predetermined force may be a differential force between the inner lock segment portions 910 and the outer lock segment portions 920. The predetermined force may cause the shear elements 930 to shear, which may decouple the inner lock segment portions 910 from the outer lock segment portions 920. This is shown in
The method 1000 may also include moving the inner mandrel 202 and the inner lock segment portions 910 in the uphole direction, as at 1050. Moving the inner mandrel 202 and the inner lock segment portions 910 in the uphole direction may cause the slips 212 of the anchor 202 to retract, as described above, thereby causing the anchor 200 to become unstuck.
The inner lock segment portions 910 may be positioned in an annulus 950 between the inner mandrel 202 and the outer tubular member (e.g., the lower sub 218 and/or the torque mandrel 224), which may allow the inner lock segment portions 910 to be moved together with the inner mandrel 202. The inner mandrel 202 and the inner lock segment portions 910 may be moved with respect to the outer lock segment portions 920, the outer tubular member (e.g., the lower sub 218 and/or the torque mandrel 224), the packer 300, or a combination thereof, which may remain stationary. The outer lock segment portions 920 may be positioned in a recess in an inner surface of the outer tubular member (e.g., the lower sub 218 and/or the torque mandrel 224), which may prevent the outer lock segment portions 920 from being moved together with the inner mandrel 202 and the inner lock segment portions 910. The recess may be radially-outward from the annulus 950.
The method 1000 may also include withdrawing the anchor-packer assembly 100 from the well, as at 1060. This is also shown in
As used herein, the terms “inner” and “outer”; “up” and “down”; “upper” and “lower”; “upward” and “downward”; “above” and “below”; “inward” and “outward”; “uphole” and “downhole”; and other like terms as used herein refer to relative positions to one another and are not intended to denote a particular direction or spatial orientation. The terms “couple,” “coupled,” “connect,” “connection,” “connected,” “in connection with,” and “connecting” refer to “in direct connection with” or “in connection with via one or more intermediate elements or members.”
While the present teachings have been illustrated with respect to one or more implementations, alterations and/or modifications may be made to the illustrated examples without departing from the spirit and scope of the appended claims. In addition, while a particular feature of the present teachings may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular function. Furthermore, to the extent that the terms “including,” “includes,” “having,” “has,” “with,” or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term “comprising.” Further, in the discussion and claims herein, the term “about” indicates that the value listed may be somewhat altered, as long as the alteration does not result in nonconformance of the process or structure to the illustrated embodiment.
Other embodiments of the present teachings will be apparent to those skilled in the art from consideration of the specification and practice of the present teachings disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the present teachings being indicated by the following claims.
