Flow control device retrieval tool and method

Information

  • Patent Grant
  • 6230797
  • Patent Number
    6,230,797
  • Date Filed
    Friday, July 16, 1999
    25 years ago
  • Date Issued
    Tuesday, May 15, 2001
    23 years ago
Abstract
A retrieval tool provides enhanced functionality for retrieving an item of equipment from within a tubular string in a subterranean well. In a described embodiment, a retrieval tool includes an anchoring device. The anchoring device releasably secures the retrieval tool in the tubular string relative to the item of equipment to be retrieved. An actuator of the retrieval tool may then displace a latching mechanism relative to the anchoring device, thereby displacing the item of equipment relative to the tubular string. The latching device may latchingly engage the item of equipment in response to displacement of the latching mechanism by the actuator.
Description




BACKGROUND OF THE INVENTION




The present invention relates generally to operations performed in conjunction with subterranean wells and, in an embodiment described herein, more particularly provides a tool for retrieving items of equipment from within tubular strings in subterranean wells.




It is common for items of equipment to be releasably secured within tubular strings in subterranean wells. For example, a flow control device, such as a safety valve, may be releasably secured in a tubing string by means of a lock mandrel attached thereto. The lock mandrel typically includes an anchoring mechanism, which prevents displacement of the mandrel relative to the tubing string, and at least one seal, which engages a seal bore of the tubing string.




Over time, it may become very difficult to release the lock mandrel from its engagement with the tubing string in order to retrieve the lock mandrel and safety valve for service, replacement, etc. Often, the lock mandrel is difficult to displace relative to the tubing string due to the seal adhering to the seal bore. Thus, it is sometimes necessary to apply a very large amount of force to the lock mandrel to get it free from the tubing string. This may be accomplished by, for example, using jars to repetitively apply an impact to the lock mandrel. However, where the lock mandrel and/or safety valve are relatively heavy, where it is desired to prevent damage to the lock mandrel from impact, or where the lock mandrel is very stuck in the tubing string, it may not be desirable or effective to use the jarring method to retrieve the lock mandrel and safety valve.




Therefore, it may be seen that it would be very desirable to provide another method for retrieving an item of equipment from within a tubular string in a subterranean well. It is accordingly an object of the present invention to provide such a method and an associated retrieval tool.




SUMMARY OF THE INVENTION




In carrying out the principles of the present invention, in accordance with an embodiment thereof, a retrieval tool is provided which solves the problem of retrieving items of equipment from within tubular strings in subterranean wells. The retrieval tool does not require any jarring or any excessive force to be applied thereto in order to retrieve heavy or stuck items of equipment. Associated methods of retrieving items of equipment are also provided.




In one aspect of the present invention, a retrieval tool is provided which includes an actuator for applying a controlled force to the item of equipment. The retrieval tool also includes an anchoring device and a latching mechanism. The anchoring device releasably secures the retrieval tool in a tubing string relative to the item of equipment. The latching mechanism latches the retrieval tool to the item of equipment. The actuator displaces at least a portion of the latching mechanism relative to the anchoring device to thereby displace the item of equipment relative to the tubing string.




In another aspect of the present invention, a retrieval tool is provided which includes a releasing device. The releasing device is configured to release an item of equipment from securement to a tubular string. For example, the item of equipment may include a portion thereof which maintains the item of equipment secured in position in a tubing string. The releasing device displaces the item of equipment portion, thereby permitting release of the item of equipment from the tubing string.




Various methods are provided for accomplishing the release of the item of equipment from securement to the tubing string. In one embodiment, the releasing device displaces the item of equipment portion when the retrieval tool is inserted into the item of equipment. In another embodiment, the releasing device is included in a latching mechanism of the retrieval tool, such that the item of equipment is released for displacement relative to the tubing string when at least a portion of the latching mechanism is displaced to latch the retrieval tool to the item of equipment.




In yet another aspect of the present invention, a method of retrieving an item of equipment from within a tubular string is provided by the present invention. The method includes the steps of conveying a retrieval tool into the tubular string, anchoring the retrieval tool within the tubular string, latching the retrieval tool to the item of equipment and displacing at least a portion of a latching mechanism of the retrieval tool relative to an anchoring device of the retrieval tool. An actuator may be included in the retrieval tool for displacing the latching mechanism in the method.




These and other features, advantages, benefits and objects of the present invention will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the invention hereinbelow and the accompanying drawings.











BRIEF DESCRIPTION OF THE DRAWINGS





FIGS. 1A&B

are cross-sectional views through a first retrieval tool embodying principles of the present invention, the tool being shown in a configuration in which it is conveyed into engagement with a lock mandrel for a flow control device;





FIGS. 2A&B

are cross-sectional views of the retrieval tool of

FIG. 1

, the tool being shown in a configuration in which it is engaged with a nipple interconnected in a tubular string above the mandrel and has released the mandrel for displacement relative to the tubular string;





FIGS. 3A&B

are cross-sectional views of the retrieval tool of

FIG. 1

, the tool being shown in a configuration in which it has latchingly engaged the mandrel;





FIGS. 4A&B

are cross-sectional views of the retrieval tool of

FIG. 1

, the tool being shown in a configuration in which it is retrieving the mandrel;





FIG. 5

is a cross-sectional view of a second retrieval tool embodying principles of the present invention, the tool being shown in a configuration in which it is conveyed into engagement with a lock mandrel for a flow control device;





FIG. 6

is a cross-sectional view of the second retrieval tool, the tool being shown in a configuration in which lugs thereof have been engaged with the mandrel;





FIG. 7

is a cross-sectional view of the second retrieval tool, the tool being shown in a configuration in which the mandrel has been released for displacement relative to a tubular string; and





FIG. 8

is a cross-sectional view of the second retrieval tool, the tool being shown in a configuration in which it is retrieving the mandrel.











DETAILED DESCRIPTION




Representatively illustrated in

FIGS. 1A&B

is a method


10


of retrieving an item of equipment


12


which method embodies principles of the present invention. In the following description of the method


10


and other apparatus and methods described herein, directional terms, such as “above”, “below”, “upper”, “lower”, etc., are used for convenience in referring to the accompanying drawings. Additionally, it is to be understood that the various embodiments of the present invention described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., without departing from the principles of the present invention.




In the method


10


as described herein, a retrieval tool


14


is used to retrieve the item of equipment


12


from within a tubing string


16


to which the item of equipment is releasably secured. The item of equipment


12


is representatively a lock mandrel, also known as a locating and locking mandrel, which may be attached to a safety valve (not shown) as described in a copending patent application entitled LOCATING AND LOCKING MANDREL FOR FLOW CONTROL DEVICE, having Leo G. Collins as an inventor thereof, U.S. application Ser. No. 09/353,722, filed Jul. 14, 1999. The disclosure of the copending application is incorporated herein by this reference. However, it is to be clearly understood that the method


10


may be used to retrieve other items of equipment and other types of equipment, and the retrieval tool


14


may be used in other methods, without departing from the principles of the present invention.




The mandrel


12


includes one or more keys


18


(only one of which is visible in FIG.


1


B), which is engaged with an internal profile


20


of the tubing string


16


. Such engagement between the key


18


and the profile


20


releasably secures the mandrel


12


relative to the tubing string


16


. The key


18


is maintained in engagement with the profile


20


by a locking sleeve


22


which radially outwardly supports the key. Thus, in order to release the mandrel


12


from its securement to the tubing string


16


, the sleeve


22


must be displaced so that it no longer maintains the key


18


in engagement with the profile


20


.




The mandrel


12


also includes a seal


24


sealingly engaged with a seal bore


26


formed in the tubing string


16


. Over time, the seal


24


may become adhered to the seal bore


26


, or it may otherwise become difficult to remove the seal from the seal bore. Therefore, it is desirable for the retrieval tool


14


to apply a large, controlled force to the mandrel


12


after the key


18


is released from its engagement with the profile


20


, in order to displace the mandrel relative to the tubing string


16


. Of course, there may be other reasons, such as debris collected about the mandrel


12


, etc., for applying the large, controlled force to the mandrel to displace it relative to the tubing string


16


.




The retrieval tool


14


includes an actuator


28


, an anchoring device


30


, a latching mechanism


32


and a releasing device


34


. The releasing device


34


includes multiple release members or dogs


36


(only one of which is visible in FIG.


1


A), each of which is radially outwardly biased by a spring


38


. The dog


36


extends radially outward through a sidewall of an outer tubular housing


40


. The spring


38


is retained between the outer housing


40


and an inner tubular housing


42


. The inner and outer housings


40


,


42


are threadedly attached to each other at the bottom end of the releasing device


34


, and the outer housing


40


is attached to the actuator


28


and the latching mechanism


32


by one or more shear members


44


, although in normal operation the outer housing is not released by shearing the shear members.




The actuator


28


may be any actuator capable of applying a force to the latching mechanism


32


, and displacing the latching mechanism relative to the anchoring device


30


. The representatively illustrated actuator


28


is a conventional Downhole Power Unit (DPU) available from Halliburton Energy Services, Inc. The DPU is typically conveyed on slickline and operates on battery power. However, it is to be clearly understood that other actuators, and other types of actuators, may be used in the retrieval tool


14


, without departing from the principles of the present invention. For example, the actuator


28


may instead be conveyed on coiled tubing, segmented tubing, electric line, wireline, etc., and the actuator may be hydraulically, mechanically, chemically, electrically, or otherwise operated.




The actuator


28


is connected to the latching mechanism


32


by an adapter


46


. Of course, if an actuator other than the DPU is used in the tool


14


, the adapter


46


may accordingly have a different configuration. The adapter


46


is releasably secured to the latching mechanism


32


and the releasing device


34


by the shear members


44


.




The latching mechanism


32


includes multiple lugs


48


(only one of which is visible in FIG.


1


A), which are radially outwardly extendable through a sidewall of an outer sleeve


50


. Note that, as shown in

FIG. 1A

, the lug


48


is received in an annular recess


52


formed externally on a tubular extension


54


. In this configuration, the lug


48


is in its radially retracted position, permitting it to enter into an upper head or fishing neck


56


of the mandrel


12


. The extension


54


is attached to the anchoring device


30


by means of a split ring or C-ring


58


.




The anchoring device


30


includes upper and lower housings


60


,


62


, respectively. The housings


60


,


62


are threaded to each other, thereby capturing the C-ring


58


therebetween and attaching the extension


54


to the anchoring device


30


. The threaded engagement between the housings


60


,


62


also retains a colletted member


64


axially therebetween. The colletted member


64


has multiple resilient collets


66


formed thereon, which are complementarily shaped relative to an annular profile


68


formed internally on a tubular nipple


70


interconnected in the tubing string


16


.




Engagement between the collets


66


and the profile


68


is used to position the retrieval tool


14


relative to the mandrel


12


and resist a force applied by the actuator


28


to the mandrel, as described in more detail below. However, it is to be clearly understood that other means of anchoring the retrieval tool


14


relative to the tubing string


16


may be utilized, without departing from the principles of the present invention. For example, the anchoring device


30


could include one or more slips, of the type used on packers, hangers, etc., which could be grippingly engaged with the interior of the tubing string


16


. Therefore, it is not necessary for the anchoring device


30


to include the collets


66


, or for the tubing string


16


to include the profile


68


.




As depicted in

FIG. 1A

, the retrieval tool


14


has not yet displaced downward far enough for the collets


66


to engage the profile


68


, and so it appears that an interference fit is experienced between the collets and the nipple


70


. In actual practice, the collets


66


are bowed inward when such a potential interference fit is experienced, thereby permitting the anchoring device


30


to pass through such restrictions. However, when the collets


66


displace downward sufficiently for the collets to align with the profile


68


, they will spring outward into engagement with the profile and prevent further downward displacement of the retrieval tool


30


.




The method


10


is representatively depicted in

FIG. 1A

as the retrieval tool


14


is being inserted into the mandrel


12


. At this point, the dogs


36


of the releasing device


34


have engaged the top of the locking sleeve


22


. Further downward displacement of the retrieval tool


14


will, thus, cause the locking sleeve


22


to be displaced downwardly therewith, thereby permitting the keys


18


to disengage from the profile


20


.




Referring additionally now to

FIGS. 2A&B

, the retrieval tool


14


is depicted in a configuration in which it has been downwardly displaced sufficiently far for the collets


66


to engage the profile


68


and, therefore, the tool is prevented from displacing further downward. Note, also, that downward displacement of the tool


14


has caused the dogs


36


to displace the locking sleeve


22


downward, so that the sleeve no longer radially outwardly supports the keys


18


in engagement with the profile


20


. Thus, the mandrel


12


is now released for displacement relative to the tubing string


16


. However, note that the seal


24


remains engaged within the seal bore


26


and may hinder retrieval of the mandrel


12


from the tubing string


16


.




Referring additionally now to

FIGS. 3A&B

, the retrieval tool


14


is depicted in a configuration in which it is latchingly engaged with the is mandrel


12


, so that an upward force may be applied to the mandrel to free it from the tubing string


16


. The actuator


28


has been operated to displace the sleeve


50


and lugs


48


upward, while the extension


54


remains anchored relative to the tubing string


16


. Such upward displacement of the sleeve


50


and lugs


48


causes the lugs to displace radially outward out of the recess


52


. Thus, the extension


54


now radially outwardly supports the lugs


48


in engagement with an internal annular profile


72


formed in the fishing neck


56


. Note that the releasing device


34


is displaced upwardly by the actuator


28


along with the sleeve


50


and the lugs


48


, but displacement of the releasing device has no effect at this time, since the keys


18


remain disengaged from the profile


20


.




Referring additionally now to

FIGS. 4A&B

, the retrieval tool


14


is depicted in a configuration in which the actuator


28


has applied sufficient force to the mandrel


12


to raise it upwardly relative to the tubing string


16


. The seal


24


has now been displaced relative to the seal bore


26


and, if the seal was previously adhered to the seal bore, such adhesion has been overcome by the force exerted by the actuator


28


. The retrieval tool


14


, the mandrel


12


and any other equipment which may be attached thereto, such as a safety valve, may now be conveyed upwardly out of the tubing string


16


.




Referring additionally now to

FIGS. 5-8

, another embodiment of a method


80


for retrieving an item of equipment


82


from a tubular string is representatively illustrated. The method


80


is similar in many respects to the method


10


described above, and utilizes a retrieval tool


84


similar in many respects to the retrieval tool


14


described above. Accordingly, the same reference numbers are used in

FIGS. 5-8

to indicate elements which are similar to elements previously described.




The item of equipment


82


in the representatively illustrated method


80


is a lock mandrel similar to the mandrel


12


described above, but which differs in at least one significant respect. The mandrel


82


is alternately secured and released for displacement relative to the tubing string


16


by displacing a locking sleeve


86


, which is attached to a fishing neck


88


of the mandrel, instead of by displacing the separate locking sleeve


22


independently of the fishing neck


56


. In

FIG. 5

, it may be seen that a radially enlarged surface


90


formed externally on the sleeve


86


radially outwardly supports the keys


18


in engagement with the profile


20


.




The retrieval tool


84


does not displace the locking sleeve


86


when the tool is inserted into the mandrel


82


. Instead, the locking sleeve


86


is displaced by a latching mechanism


92


which, in turn, is displaced by the actuator


28


. Thus, the latching mechanism


92


can, in this sense, be said to include a releasing device, since it operates to release the mandrel


82


from its securement to the tubing string


16


.




In

FIG. 5

, the retrieval tool


84


is shown in a configuration in which it has been conveyed into the tubing string


16


and downwardly displaced therein until the collets


66


engage the profile


68


. Further downward displacement of the retrieval tool


84


is, therefore, prevented. Note that a sleeve


94


of the latching mechanism


92


also contacts an interior surface of the fishing neck


88


.




Referring additionally now to

FIG. 6

, the retrieval tool


84


is shown in a configuration in which the actuator


28


has been operated to displace the sleeve


94


and lugs


48


upwardly relative to the extension


54


. In this manner, the lugs


48


are displaced radially outward out of the recess


52


and into engagement with the profile


72


in the fishing neck


88


. The lugs


48


are radially outwardly supported in engagement with the profile


72


by the extension


54


.




Referring additionally now to

FIG. 7

, the retrieval tool


84


is shown in a configuration in which the actuator


28


has been operated to displace the sleeve


94


, lugs


48


, fishing neck


88


and locking sleeve


86


upwardly, the lugs remaining engaged in the profile


72


. At this point, the keys


18


are no longer radially outwardly supported by the sleeve


86


and the mandrel


82


is released for displacement relative to the tubing string


16


. Note that, although it appears in

FIG. 7

that the lugs


48


are no longer radially outwardly supported by the extension


54


, the visible lug


48


is shown rotated out of its actual position and, in actual practice, the lugs remain supported by the extension when the retrieval tool


84


is in this configuration.




Referring additionally now to

FIG. 8

, the retrieval tool


84


is depicted in a configuration in which the actuator


28


has applied sufficient force to the mandrel


82


to raise it upwardly relative to the tubing string


16


. The seal


24


has now been displaced relative to the seal bore


26


and, if the seal was previously adhered to the seal bore, such adhesion has been overcome by the force exerted by the actuator


28


. The retrieval tool


84


, the mandrel


82


and any other equipment which may be attached thereto, such as a safety valve, may now be conveyed upwardly out of the tubing string


16


.




If, after the retrieval tool


14


or


84


has been engaged with the mandrel


12


or


82


, and the actuator


28


applies force to the mandrel to displace it relative to the tubing string


16


, but the mandrel remains stuck in the tubing string, the actuator will eventually apply a sufficiently large force to shear the shear members


44


. In this manner, the actuator


28


and anchoring device


30


may then be retrieved from the tubing string


16


. If the actuator


28


should malfunction, for example, so that it cannot apply a sufficient force to displace the mandrel


12


or


82


, or shear the shear members


44


, and if the retrieval tool


14


or


84


cannot be disengaged from the mandrel, the shear members


44


may then be sheared by applying an upwardly directed force to the actuator


28


.




Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the invention, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to these specific embodiments, and such changes are contemplated by the principles of the present invention. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims.



Claims
  • 1. A tool for retrieving an item of equipment from within a tubular string disposed within a subterranean well, the tool comprising:an actuator; an anchoring device configured for releasably securing the actuator within the tubular string; and a latching mechanism engageable downhole with the item of equipment, whereby the actuator applies a force to the item of equipment via the latching mechanism to retrieve the item of equipment from the tubular string, the force being resisted by the anchoring device, when the retrieval tool is engaged with the item of equipment downhole, wherein the actuator displaces at least a portion of the latching mechanism relative to the anchoring device, and wherein the portion of the latching mechanism displaced by the actuator latchingly engages the item of equipment in response to the displacement of the latching mechanism portion by the actuator.
  • 2. A tool for retrieving an item of equipment from within a tubular string disposed within a subterranean well, the tool comprising:an actuator; an anchoring device configured for releasably securing the actuator within the tubular string; and a latching mechanism engageable downhole with the item of equipment, whereby the actuator applies a force to the item of equipment via the latching mechanism to retrieve the item of equipment from the tubular string, the force being resisted by the anchoring device, when the retrieval tool is engaged with the item of equipment downhole, and wherein the actuator and anchoring device are releasably secured to the latching mechanism.
  • 3. The retrieval tool according to claim 2, wherein a shear member releasably secures the actuator and anchoring device to the latching mechanism.
  • 4. A tool for retrieving an item of equipment from within a tubular string disposed within a subterranean well, the tool comprising:an actuator; an anchoring device configured for releasably securing the actuator within the tubular string; and a latching mechanism engageable downhole with the item of equipment, whereby the actuator applies a force to the item of equipment via the latching mechanism to retrieve the item of equipment from the tubular string, the force being resisted by the anchoring device, when the retrieval tool is engaged with the item of equipment downhole, and wherein an engagement member of the latching mechanism is outwardly extended into latching engagement with an internal profile of the item of equipment in response to displacement of a portion of the latching mechanism by the actuator.
  • 5. A tool for retrieving an item of equipment releasably secured within a tubular string disposed within a subterranean well, the tool comprising:a latching mechanism configured for latching engagement with the item of equipment; a releasing device configured for releasing the item of equipment from securement to the tubular string; and an anchoring device configured for releasably securing the latching mechanism and releasing device relative to the item of equipment.
  • 6. The retrieval tool according to claim 5, wherein the releasing device displaces a portion of the item of equipment maintaining the item of equipment secured relative to the tubular string in response to insertion of the retrieval tool into the item of equipment.
  • 7. The retrieval tool according to claim 5, wherein the releasing device includes an outwardly extending release member, the release member engaging and causing displacement of a portion of the item of equipment, thereby releasing the item of equipment from securement relative to the tubular string, when the retrieval tool is received in the item of equipment.
  • 8. The retrieval tool according to claim 5, wherein the releasing device is included in the latching mechanism, the item of equipment being released from securement to the tubular string when the latching mechanism is latchingly engaged with a portion of the item of equipment maintaining the item of equipment secured relative to the tubular string and the latching mechanism is displaced relative to the anchoring device.
  • 9. The retrieval tool according to claim 5, further comprising an actuator attached to the anchoring device.
  • 10. The retrieval tool according to claim 9, wherein the actuator displaces at least a portion of the latching mechanism relative to the anchoring device.
  • 11. The retrieval tool according to claim 10, wherein the latching mechanism latchingly engages the item of equipment when the retrieval tool is operatively received in the item of equipment and the latching mechanism portion is displaced relative to the anchoring device.
  • 12. A method of retrieving an item of equipment from within a tubular string in which the item of equipment is releasably secured, the method comprising the steps of:conveying a retrieval tool into the tubular string; anchoring the retrieval tool within the tubular string using an anchoring device of the retrieval tool, by engaging a collet of the anchoring device with an internal profile formed in a nipple interconnected in the tubular string; latching the retrieval tool to the item of equipment using a latching mechanism of the retrieval tool; and displacing at least a portion of the latching mechanism relative to the anchoring device.
  • 13. A method of retrieving an item of equipment from within a tubular string in which the item of equipment is releasably secured, the method comprising the steps of:conveying a retrieval tool into the tubular string; anchoring the retrieval tool within the tubular string using an anchoring device of the retrieval tool; latching the retrieval tool to the item of equipment using a latching mechanism of the retrieval tool; and displacing at least a portion of the latching mechanism relative to the anchoring device, and wherein the latching step is performed in response to the displacement of at least the portion of the latching mechanism relative to the anchoring device.
  • 14. A method of retrieving an item of equipment from within a tubular string in which the item of equipment is releasably secured, the method comprising the steps of:conveying a retrieval tool into the tubular string; anchoring the retrieval tool within the tubular string using an anchoring device of the retrieval tool; latching the retrieval tool to the item of equipment using a latching mechanism of the retrieval tool; displacing at least a portion of the latching mechanism relative to the anchoring device; and displacing a member of the item of equipment maintaining the item of equipment secured relative to the tubular string.
  • 15. The method according to claim 14, wherein the member displacing step is performed in response to insertion of the retrieval tool into the item of equipment.
  • 16. The method according to claim 14, wherein the member displacing step is performed in response to the latching mechanism portion displacing step.
  • 17. The method according to claim 14, wherein the member is attached to a portion of the item of equipment latchingly engaged by the latching mechanism, and wherein the member and the item of equipment portion are displaced with the latching mechanism portion in the latching mechanism portion displacing step.
  • 18. A method of retrieving an item of equipment from within a tubular string in which the item of equipment is releasably secured, the method comprising the steps of:conveying a retrieval tool into the tubular string; anchoring the retrieval tool within the tubular string using an anchoring device of the retrieval tool; latching the retrieval tool to the item of equipment using a latching mechanism of the retrieval tool; and displacing at least a portion of the latching mechanism relative to the anchoring device, thereby removing a seal of the item of equipment from a seal bore of the tubular string.
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2984302 Churchj May 1961
4715445 Smith, Jr. Dec 1987
4883120 Schasteen et al. Nov 1989
5398753 Obrejanu et al. Mar 1995
5765638 Taylor Jun 1998
5947202 Gazewood Sep 1999