LINER HANGER RUNNING TOOL WITH CONTINGENCY RELEASE

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of the filing date of U.S. provisional application No. 63/651,763 filed on 24 May 2024. The entire disclosure of the prior application is incorporated herein by this reference for all purposes.

BACKGROUND

This disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in examples described below, more particularly provides a liner hanger running tool.

A liner is a protective lining used in a wellbore. A liner hanger is used to anchor the liner in a previously installed liner or casing.

After the liner hanger has been set in the previous liner or casing, it is normal procedure to release a running tool from the liner hanger, so that the running tool and a work string used to convey the liner into the well can be retrieved from the well. Unfortunately, in some circumstances the running tool fails to release from the set liner hanger. This situation can result in expensive and time-consuming operations to mitigate this problem.

It will, therefore, be appreciated that improvements are continually needed in the art of designing, constructing and operating running tools for use in subterranean wells. The present disclosure provides such improvements, which may be used in a variety of different types of well environments and well configurations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representative partially cross-sectional view of an example of a well system and associated method which can embody principles of this disclosure.

FIGS. 2A & B are representative partially cross-sectional views of examples of a liner hanger and a running tool that may be used in the FIG. 1 well system and method.

FIG. 3 is a representative partially cross-sectional view of the running tool in a run-in configuration.

FIG. 3A is a representative cross-sectional view of the running tool, taken along line 3A-3A of FIG. 3.

FIG. 4 is a representative partially cross-sectional view of the running tool in a partially hydraulically released configuration.

FIG. 5 is a representative partially cross-sectional view of the running tool in a fully hydraulically released configuration.

FIG. 6 is a representative partially cross-sectional view of the running tool in a configuration in which a contingency release procedure is initiated.

FIG. 7 is a representative partially cross-sectional view of the running tool in a contingency partially released configuration.

FIG. 8 is a representative partially cross-sectional view of the running tool in a contingency released configuration.

DETAILED DESCRIPTION

Representatively illustrated in FIG. 1 is a system 10 for use with a subterranean well, and an associated method, which can embody principles of this disclosure. However, it should be clearly understood that the system 10 and method are merely one example of an application of the principles of this disclosure in practice, and a wide variety of other examples are possible. Therefore, the scope of this disclosure is not limited at all to the details of the system 10 and method described herein and/or depicted in the drawings.

As depicted in FIG. 1, a liner string 12 is installed in a wellbore 14 and is secured to a previously installed liner or casing 16 with a liner hanger 18. A work string 20 with a running tool 22 is used to convey the liner string 12 in the wellbore 14, and then to set the liner hanger 18 when it is appropriately positioned in the previous liner or casing 16.

In the FIG. 1 example, the liner hanger 18 is set by applying increased pressure in the work string 20. The applied pressure causes slips 26 to extend outward from the liner hanger 18 and grip an interior surface of the previous liner or casing 16. A packer section 28 of the liner hanger 18 includes additional slips 30 and an annular seal 32 that extend outwardly to grip the interior surface and seal against the interior surface, respectively, after the initial slips 26 are set.

After the liner hanger 18 is set, the running tool 22 is released from the liner hanger, so that the running tool and the remainder of the work string 20 can be retrieved from the well. The work string 20 may be manipulated at the surface of the well in order to release the running tool 22 from the liner hanger 18. For example, the work string 20 may be rotated in a clockwise (right-hand as viewed from above) or counter-clockwise (left-hand as viewed from above) rotational direction using a rotary table, tong, iron roughneck or other torque applying apparatus, and the work string may be picked up (raised) or slacked-off (lowered) at the surface using a draw works, top drive or other lifting apparatus. The running tool 22 in this example includes features that allow the running tool to be released from the liner hanger 18, even if an initial attempt to release the running tool is unsuccessful.

Referring additionally now to FIGS. 2A & B cross-sectional views of examples of the liner hanger 18 and the running tool 22 are representatively illustrated. The liner hanger 18 and the running tool 22 are described below as they may be used in the FIG. 1 system 10 and method, but the liner hanger and running tool may be used in other systems and methods in keeping with the scope of this disclosure.

An internally threaded upper connector 34 of the running tool 22 includes torque locks 36 to allow torque to be applied from the work string 20 to the running tool and liner hanger 18 in both clockwise and counter-clockwise rotational directions. The upper connector 34 is formed at an upper end of a generally tubular mandrel 38 of the running tool 22.

Torque applied to the mandrel 38 is transmitted to an outer housing 40 via screws 42 (only one of which is visible in FIG. 2A). In this example, the outer housing 40 includes two sections 40a,b joined by castellations 44. An upper end of the liner hanger 18 is connected to the lower outer housing section 40b with additional castellations 46.

An externally threaded float nut 48 is used to secure the liner hanger 18 to the running tool 22. The float nut 48 is disposed on axially extending keys 50 (only one of which is visible in FIGS. 2A & B) that are secured on the mandrel 38. The keys are received in axially extending slots formed in the float nut 48. The keys 50 are constrained to rotate with the mandrel 38, so rotation of the mandrel also causes rotation of the float nut 48.

The float nut 48 is left-hand threaded into the upper end of the liner hanger 18. Thus, right-hand (clockwise as viewed from above) rotation of the mandrel 38 relative to the liner hanger 18 will cause the float nut 48 to unthread from the liner hanger.

In a procedure described more fully below for releasing the running tool 22 from the liner hanger 18, the work string 20 is slacked off, thereby applying a compressive load to the running tool, before rotating the work string and mandrel 38. A bearing 52 is provided in the running tool 22 to mitigate any excessive friction due to the compressive load.

A coil spring 54 applies a downwardly biasing force to a torque lock 56 engaged with the keys 50 and the outer housing 40. As described more fully below, the torque lock 56 must be disengaged from the keys 50 to permit the mandrel 38 to rotate relative to the outer housing 40 and the liner hanger 18. The torque lock 56 is disengaged by applying the compressive load to the running tool 22, with the compressive load being sufficient to overcome the biasing force exerted by the coil spring 54.

However, the mandrel 38 is prevented from displacing downward relative to the outer housing 40 to compress the spring 54 by dogs 58 (only one of which is visible in FIG. 2A) engaged in a circumferentially extending slot 60 formed on the mandrel. The dogs 58 extend radially through an upper end of the outer housing upper section 40a.

The dogs 58 are radially inwardly supported in engagement with the slot 60 by a release sleeve 62 surrounding the mandrel 38. An annular piston 64 is secured in the release sleeve 62.

Ports 76 formed through the mandrel 38 permit pressure applied to the interior of the work string 20 and the mandrel to be communicated to an annular chamber between the mandrel and the annular piston 64. When sufficient pressure is applied to the interior of the mandrel 38, the release sleeve 62 will displace upward, to thereby permit the dogs 58 to displace radially outward and out of engagement with the slot 60.

Shear screws 66 extend through the outer housing upper section 40a and into axially extending slots 68 (only one of which is visible in FIG. 2A) formed on the mandrel 38. When the shear screws 66 are in the axial slots 68, they releasably secure the mandrel 38 against rotation relative to the outer housing 40. However, when the mandrel 38 is displaced downward relative to the outer housing 40 by the compressive load due to slacking off on the work string 20 at the surface, the shear screws 66 are received in a circumferentially extending slot 70 formed on the mandrel, and the shear screws 66 at that point will not resist rotation of the mandrel relative to the outer housing 40.

Shear screws 72 extend through the outer housing upper section 40a and into axially extending slots 74 (only one of which is visible in FIG. 2A) formed on the mandrel 38. When the shear screws 72 are aligned with the axially extending slots 74 as depicted in FIG. 2A, the shear screws do not impede downward displacement of the mandrel 38 relative to the outer housing 40. However, if the mandrel 38 is rotated counter-clockwise relative to the outer housing 40, as described more fully below, the shear screws will no longer be aligned with the axial slots 74 and will releasably prevent downward displacement of the mandrel relative to the outer housing.

Referring additionally now to FIG. 3, a partially cross-sectional view of an example of the running tool 22 in a run-in configuration is representatively illustrated. The FIG. 3 running tool 22 may be used with the liner hanger 18, or it may be used with other liner hangers. The FIG. 3 running tool 22 is similar in most respects to the FIGS. 2A & B running tool, so the same reference numbers are used in FIG. 3 to indicate components similar to those described above.

One difference in the FIG. 3 example is that additional shear screws 66 are used. Another difference is that a snap ring 78 is carried in an upper end of the release sleeve 62 for engagement with a groove 80 formed on the mandrel 38 below the upper connector 34 when the release sleeve is displaced upward. In other examples, the snap ring 78 could instead be carried on the mandrel 38 and the groove 80 could be formed in the release sleeve 62.

In FIG. 3 it may be seen that the shear screws 72 are received in a circumferentially extending slot 82 formed on the mandrel 38, as well as in the axially extending slot 74. Thus, in the run-in configuration of the running tool 22, the shear screws 72 do not prevent axial displacement or rotation of the mandrel 38 relative to the outer housing 40. However, it will be appreciated that, if the mandrel 38 is rotated appropriately relative to the outer housing 40, the shear screws 72 will no longer be aligned with the axial slots 74, at which point the shear screws will releasably prevent downward displacement of the mandrel relative to the outer housing.

Another shear screw 84 releasably secures the release sleeve 62 to the annular piston 64. The piston 64 is threaded onto the inner mandrel 38.

Referring additionally now to FIG. 3A, a cross-sectional view of the running tool 22, taken along line 3A-3A of FIG. 3 is representatively illustrated. In this view, a configuration of the torque lock 56 and its interaction with the keys 50 and the outer housing 40 can be more clearly seen.

In this example, the torque lock 56 is secured in the lower outer housing section 40b with the torque screws 42. The keys 50 are received in circumferentially extending slots 88 formed in the torque lock 56, and in axially extending slots 90 formed in the mandrel 38.

The circumferential slots 88 permit only limited rotation of the mandrel 38 and keys 50 relative to the outer housing 40. Specifically, the circumferential slots 88 permit only limited counter-clockwise (left-hand) rotation of the mandrel 38 and keys 50 relative to the outer housing 40. When the mandrel 38 and keys 50 are rotated counter-clockwise relative to the outer housing 40 to the extent permitted by the slots 88, as described more fully below, the shear screws 72 will not be aligned with the axial slots 74, and so the shear screws will resist downward displacement of the mandrel relative to the outer housing.

Referring additionally now to FIG. 4, a partially cross-sectional view of the running tool 22 in a partially released configuration is representatively illustrated. In this view, sufficient fluid pressure has been applied to the interior of the work string 20 and mandrel 38 to shear the shear screws 84 and displace the release sleeve 62 upward. The snap ring 78 can now engage the groove 80 to maintain the release sleeve 62 in this position.

The release sleeve 62 no longer retains the dogs 58 in engagement with the circumferential slots 60 on the mandrel 38. Thus, the mandrel 38 can now be displaced downward relative to the outer housing 40.

Referring additionally now to FIG. 5, a partially cross-sectional view of the running tool 22 in a released configuration is representatively illustrated. In this view, a compressive load has been applied to the running tool 22 by slacking off on the work string 20 at the surface. The compressive load is sufficient to compress the spring 54 and displace the mandrel 38 downward relative to the outer housing 40.

The downward displacement of the mandrel 38 relative to the outer housing 40 has caused the keys 50 to disengage from the circumferential slots 88 of the torque lock 56. This disengagement allows the mandrel 38 to be rotated relative to the outer housing 40.

Note that the shear screws 66 are no longer received in the axial slots 68, but are instead received in the circumferential slot 70 on the mandrel 38. Thus, the shear screws 66 do not impede rotation of the mandrel 38 relative to the outer housing 40.

Similarly, the shear screws 72 have displaced through the axial slots 74 and are now received in another circumferentially extending slot 92 formed on the mandrel 38. Thus, the shear screws 72 also do not impede rotation of the mandrel 38 relative to the outer housing 40.

The mandrel 38 is rotated in a clockwise direction relative to the outer housing 40 by rotating the work string 20 at the surface (in a right-hand direction as viewed from above). The outer housing 40 does not rotate with the mandrel 38, due to the engagement of the outer housing with the liner hanger 18 (see FIG. 2A, castellations 46).

The clockwise rotation of the mandrel 38 has caused the float nut 48 to unthread from the liner hanger 18. Note that, in FIG. 5, the float nut 48 is displaced upward relative to the mandrel 38. Thus, the running tool 22 is now released from the liner hanger 18 and can be retrieved to the surface with the remainder of the work string 20.

Referring additionally now to FIG. 6, a partially cross-sectional view of the running tool 22 in a configuration in which a contingency release procedure is initiated is representatively illustrated. The contingency release procedure is performed if the release procedure described above and depicted in FIGS. 4 & 5 is unsuccessful (for example, if the release sleeve 62 did not displace upward relative to the mandrel 38 upon application of pressure to the interior of the work string 20).

If a compressive load or force has been applied to the running tool 22 (e.g., by slacking off on the work string 20 at the surface) in the initial release procedure, then preferably the compressive load is removed, for example, by picking up on the work string. However, note that it is not necessary to remove any compressive load or force on the running tool 22 prior to commencing the contingency release procedure.

In the FIG. 6 example, the release sleeve 62 has not been displaced upward relative to the mandrel 38. Therefore, the dogs 58 are still supported in engagement with the circumferential slots 60, and so the mandrel 38 cannot be displaced downward relative to the outer housing 40 to compress the spring 54 and disengage the torque lock 56 from the keys 50 to permit rotation of the mandrel relative to the outer housing.

Referring additionally now to FIG. 7, a partially cross-sectional view of the running tool 22 in a partially released configuration is representatively illustrated. In this view, the mandrel 38 has been rotated in a left-hand direction relative to the outer housing 40 by rotating the work string 20 in a counter-clockwise direction (as viewed from above) at the surface.

Limited counter-clockwise rotation of the mandrel 38 relative to the outer housing 40 is permitted by the circumferential slots 88 in the torque lock 56 (see FIG. 3A). The shear screws 66 resist such rotation, but the shear screws will shear when sufficient torque is applied to the work string 20. Note that the shear screws 66 are sheared as depicted in FIG. 7.

Note also that the dogs 58 are now rotationally aligned with axially extending slots 92 formed on the mandrel 38. Thus, the mandrel 38 can now be displaced downward relative to the outer housing 40, even though the release sleeve 62 still prevents radially outward displacement of the dogs 58.

Due to the counter-clockwise rotation of the mandrel 38 relative to the outer housing 40, the shear screws 72 are no longer axially aligned with the axial slots 74 on the mandrel (see FIG. 6). Instead, the shear screws 72 are now rotationally aligned with circumferentially extending shoulders 94 formed on the mandrel 38. Thus, in order to displace the mandrel 38 downward relative to the outer housing 40, a sufficient compressive load will need to be applied to the mandrel 38 to shear the shear screws 72 and compress the spring 54.

Referring additionally now to FIG. 8, a partially cross-sectional view of the running tool 22 in a released configuration is representatively illustrated. In this view the mandrel 38 has displaced downward relative to the outer housing 40 by slacking off on the work string 20 at the surface. In this manner, sufficient compressive load has been applied to the running tool 20 shear the shear screws 72 and compress the spring 54.

The torque lock 56 is now disengaged from the keys 50, thereby allowing the mandrel 38 to be rotated relative to the outer housing 40. The mandrel 38 has been rotated in a right-hand direction by rotating the work string 20 in a clockwise direction at the surface.

The float nut 48 has unthreaded from the liner hanger 18, thereby releasing the running tool 22 from the liner hanger. The running tool 22 and the remainder of the work string 20 can now be retrieved from the well.

Note that, in each of the hydraulic release (FIGS. 4 & 5) and contingency release (FIGS. 6-8) procedures, as the float nut 48 unthreads from the liner hanger 18, an externally threaded torque nut 98 will rotate and displace downwards until it shoulders inside the outer housing lower section 40b. When this occurs, the torque path changes and the work string 20 and liner string 12 will rotate together.

Note that, in each of the hydraulic release and contingency release procedures, the mandrel 38 could be configured or machined so that it does not include the axially extending slots 74. In that case, the second shear upon “slack off” (shearing of the shear screws 72) will give an operator at the surface a positive indication that the running tool 22 has been placed in compression, regardless of the release mode (hydraulic release or contingency release).

It may now be fully appreciated that the above disclosure provides significant advancements to the art of designing, constructing and operating liner hanger running tools for use in subterranean wells. In one example described above, if release of the running tool 22 from the liner hanger 18 is initially unsuccessful, the mandrel 38 can be rotated counter-clockwise somewhat relative to the outer housing 40 (causing the shear screws 66 to shear) to thereby enable the mandrel to be displaced downward relative to the outer housing. Shearing of the shear screws 72 (due to the downward displacement of the mandrel 38) will provide an indication to an operator at the surface that the contingency release procedure has been successfully initiated. The mandrel 38 can then be rotated clockwise relative to the outer housing 40 to unthread the float nut 48 from the liner hanger 18.

The above disclosure provides to the art a method of releasing a work string 20 including a running tool 22 from a liner hanger 18 in a subterranean well. In one example, the method can comprise: rotating the work string 20 in a first rotational direction; then slacking off on the work string 20, thereby applying a compressive force to the running tool 22; and then rotating the work string 20 in a second rotational direction opposite to the first rotational direction, thereby releasing the running tool 22 from the liner hanger 18.

The method can include picking up on the work string 20, prior to the step of rotating the work string 20 in the first rotational direction. The first rotational direction may be a counter-clockwise rotation of the work string 20 at a surface of the well.

The step of rotating the work string 20 in the first rotational direction may comprise shearing at least one shear member 66 received in an axially extending slot 68 formed on a tubular mandrel 38 of the running tool 22.

The step of rotating the work string 20 in the first rotational direction may comprise rotationally aligning at least one dog 58 with an axially extending slot 92 formed on a tubular mandrel 38 of the running tool 22.

The dog 58 may be received in a circumferentially extending slot 60 formed on the mandrel 38.

The step of slacking off on the work string 20 may comprise displacing the mandrel 38 relative to the dog 58, thereby displacing the dog 58 through the axially extending slot 92.

The step of rotating the work string 20 in the first rotational direction may comprise aligning at least one shear member 72 with a shoulder 94 formed on a tubular mandrel 38 of the running tool 22.

The aligning step may comprise displacing the shear member 72 through a circumferentially extending slot 80 formed on the mandrel 38.

The step of slacking off on the work string 20 may comprise shearing the shear member 72.

Also provided to the art by the above disclosure is a liner hanger running tool 22. In one example, the running tool 22 can comprise: a tubular mandrel 38 with an axially extending first slot 68 formed on the mandrel 38; an outer housing 40; and a first shear member 66. The mandrel 38 has a first axial position relative to the outer housing 40 in which the first shear member 66 is received in the first slot 68 and the first shear member 66 releasably secures the mandrel 38 against rotation relative to the outer housing 40. The mandrel 38 has a second axial position relative to the outer housing 40 in which the first shear member 66 is not received in the first slot 68 and the first shear member 66 does not secure the mandrel 38 against rotation relative to the outer housing 40.

The liner hanger running tool 22 may also include a dog 58 that secures the mandrel 38 against axial movement relative to the outer housing 40. The dog 58 may be received in a circumferentially extending slot 60 formed on the mandrel 38.

A release sleeve 62 may prevent disengagement of the dog 58 from the circumferentially extending slot 60. The release sleeve 62 may be configured to permit disengagement of the dog 58 from the circumferentially extending slot 60 in response to fluid pressure applied to an interior of the mandrel 38.

The liner hanger running tool 22 may include an axially extending second slot 92 formed on the mandrel 38. The second slot 92 may be configured to axially align with the dog 58 in response to rotation of the mandrel 38 relative to the outer housing 40.

The liner hanger running tool 22 may include a torque lock 56 that limits relative rotation between the mandrel 38 and the outer housing 40 in the first axial position of the mandrel 38, and that does not limit relative rotation between the mandrel 38 and the outer housing 40 in the second axial position of the mandrel 38.

The liner hanger running tool 22 may include a second shear member 72 received in a circumferentially extending slot 80 formed on the mandrel 38, the second shear member 72 releasably securing the mandrel 38 against displacement from the first axial position to the second axial position.

The liner hanger running tool 22 may include a circumferentially extending shoulder 94 formed on the mandrel 38. The second shear member 72 may be rotationally alignable with the shoulder 94 in response to rotation of the mandrel 38 relative to the outer housing 40.

The second shear member 72 may be configured to permit the mandrel 38 to displace from the first axial position to the second axial position without shear of the second shear member 72 when the second shear member 72 is axially aligned with an axially extending second slot 74 formed on the mandrel 38.

The first shear member 66 may be rotationally aligned with a circumferentially extending slot 70 formed on the mandrel in the second axial position of the mandrel 38.

Although various examples have been described above, with each example having certain features, it should be understood that it is not necessary for a particular feature of one example to be used exclusively with that example. Instead, any of the features described above and/or depicted in the drawings can be combined with any of the examples, in addition to or in substitution for any of the other features of those examples. One example's features are not mutually exclusive to another example's features. Instead, the scope of this disclosure encompasses any combination of any of the features.

Although each example described above includes a certain combination of features, it should be understood that it is not necessary for all features of an example to be used. Instead, any of the features described above can be used, without any other particular feature or features also being used.

It should be understood that the various embodiments described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of this disclosure. The embodiments are described merely as examples of useful applications of the principles of the disclosure, which is not limited to any specific details of these embodiments.

In the above description of the representative examples, directional terms (such as “above,” “below,” “upper,” “lower,” “upward,” “downward,” etc.) are used for convenience in referring to the accompanying drawings. However, it should be clearly understood that the scope of this disclosure is not limited to any particular directions described herein.

The terms “including,” “includes,” “comprising,” “comprises,” and similar terms are used in a non-limiting sense in this specification. For example, if a system, method, apparatus, device, etc., is described as “including” a certain feature or element, the system, method, apparatus, device, etc., can include that feature or element, and can also include other features or elements. Similarly, the term “comprises” is considered to mean “comprises, but is not limited to.”

Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the disclosure, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to the specific embodiments, and such changes are contemplated by the principles of this disclosure. For example, structures disclosed as being separately formed can, in other examples, be integrally formed and vice versa. 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 invention being limited solely by the appended claims and their equivalents.