FIELD

The present disclosure relates to a swivel apparatus for use in a wellbore.

BACKGROUND

In the oil and gas exploration and production industry wellbores are drilled from surface to intercept a desired subterranean region, for example a hydrocarbon bearing reservoir. Wellbores are typically drilled in stages, with each stage requiring the newly drilled section to be lined with casing or liner, which are often cemented in place. Also, wellbore equipment will typically need to be deployed in the production zone, such as sand control equipment, for example sand screens, to minimise sand production. Many different kinds of wellbore tools, apparatus or equipment may need to be deployed.

Wellbore infrastructure (e.g., casing, liner, sand screens, tools etc.) may be deployed via a running string (such as a drill string formed of jointed tubulars). In some cases, particularly in deviated and/or extended reach horizontal wellbores, frictional forces between the running string and the wall of the wellbore may be significant, perhaps exceeding the available running force (e.g., string weight) and preventing desired deployment and/or risking damage to equipment, such as via buckling. Similar issues may exist during retrieval operations, which could result in tensile limits, winch capacities etc. being exceeded. In such cases it may be desirable to rotate the running/retrieval string to relieve static friction and thus improve deployment/retrieval capabilities. However, in some cases it might not be desirable to rotate the infrastructure being deployed or retrieved, for example if risk of damage through such rotation is high.

It is known to utilise swivels (swivel tools, subs, apparatus, joints etc.) which are arranged between a running/retrieval string and infrastructure. Such swivels rotatably decouple the running/retrieval string from the infrastructure.

Swivels may also be used to facilitate downhole tool operations, for example where rotation of a string relative to a connected tool is necessary for tool operation or actuation, such as to set packer elements, set slips, drive a jarring apparatus and/or the like.

SUMMARY

An aspect of the present disclosure relates to a swivel apparatus for use in a wellbore, the swivel apparatus comprising: a housing; a mandrel extending within the housing; wherein the mandrel and the housing are axially moveable relative to each other between: a first relative axial position in which the mandrel and housing are rotatable relative to each other; a second relative axial position in which the mandrel and housing are rotatable relative to each other; and a third relative axial position, intermediate the first and second relative axial positions, in which the housing and mandrel are rotatably coupled together.

By virtue of the swivel apparatus being for use in a wellbore the apparatus may be defined as a downhole swivel apparatus.

The first and second relative axial positions may be defined as up and down relative positions. In this respect the terms “up” and “down” may be defined relative to a wellbore in which the swivel apparatus is located when in use. That is, the term “up” may be defined as in the direction of or towards an entry point of the wellbore (i.e., uphole direction), and the term “down” may be defined as in the direction of or towards the toe of a wellbore (i.e., downhole direction).

The swivel apparatus may be reconfigurable between a swivel mode when the mandrel and housing are in their first or second relative axial positions, and a rotary locked mode when the housing and mandrel are in their third relative axial position. Such a rotary locked mode may be defined as a torque transmission mode. As such, the swivel apparatus may accommodate or provide a dual functionality. In other words, the swivel apparatus may be selectively operated (i.e., the swivel functionality may be switched on and off) in accordance with the relative axial alignment between the housing and mandrel.

The functionality of the swivel apparatus (i.e., the housing and mandrel being rotatably coupled or de-coupled) may be readily and simply altered by varying the relative axial position between the mandrel and the housing. This may minimise the requirement for complex operation means, such as separate actuators and associated control equipment, pressure actuation regimes and/or the like.

The housing may comprise a first rotary connector portion and the mandrel may comprise a second rotary connector portion. When the mandrel and the housing are in the first or second relative axial positions the first and second rotary connector portions may be disengaged, thus permitting relative rotation between the mandrel and the housing. When the mandrel and the housing are in their third relative axial position the first and second rotary connector portions may be engaged to rotatably connect the housing and mandrel relative to each other.

In use, one of the mandrel and housing may be connected to a rotary string (e.g., a work string, drill string, deployment string, retrieval string etc.), and the other of the mandrel and housing may be connected to wellbore apparatus (e.g., casing, liner, sand screen, downhole tool etc.). The apparatus may comprise appropriate connectors for this purpose, such as threaded connectors etc. Depending on the relative axial position of the housing and mandrel, the rotary string and wellbore apparatus may be rotatably coupled or de-coupled. Further, reconfiguring between the rotatably coupled and de-coupled states may be achieved by simple relative axial movement between the mandrel and housing. Such relative axial movement between the mandrel and housing in the present example may be achieved by appropriate axial manipulation of the rotary string (e.g., pulling tension in the string against the wellbore apparatus - or indeed the weight of the wellbore apparatus applying tension in the rotary string - or setting weight down on the wellbore apparatus).

In this case, when rotation of a connected rotary string is desirable without also causing rotation of the wellbore apparatus, then the swivel apparatus may be configured such that the mandrel and housing are in either of their first and second relative axial positions, the selection of which may be made in accordance with a desired axial load direction, described in more detail below. When it is desirable for rotation of the string to be transmitted to the wellbore apparatus the mandrel and housing may be located in their third relative axial position, thus providing the rotary connection. This might be required for multiple purposes, for example for operation of the wellbore apparatus, to disconnect from the wellbore apparatus and/or the like.

In one example the mandrel may be connectable to a rotary string, and the housing may be connectable to a wellbore apparatus. However, in other examples the reverse may be the case.

The housing and mandrel may be axially moveable relative to each other such that movement between the first and second relative axial positions requires transitioning or passing through the third relative axial position. The first and second relative axial positions of the housing and mandrel may define respective axial movement limits.

The swivel apparatus may comprise at least one thrust bearing assembly. The at least one thrust bearing assembly may be configured to accommodate axial load to be transmitted between the housing and mandrel. Such axial load transmission may be accommodated during relative rotation between the mandrel and housing. The at least one thrust bearing assembly may be configured to accommodate axial load to be transmitted between the housing and mandrel when in one or both of their first and second relative axial positions.

In one example the swivel apparatus may comprise a single thrust bearing assembly. In this example the single thrust bearing assembly may be bi-directional, in that axial load may be transmitted, via the thrust bearing assembly, between the housing and mandrel when in both their first and second relative axial positions. In such an example the single thrust bearing assembly may define axially opposed load faces which are engaged in accordance with the relative axial positioning of the mandrel and housing. For example, when the mandrel and housing are in their first relative axial position one load face of the thrust bearing may be engaged, and when the mandrel and housing are moved to their second relative axial position the other axial load face may be engaged. This arrangement may permit a single bearing assembly to accommodate axial load transference in reverse directions. The swivel apparatus may comprise multiple thrust bearing assemblies. In one example the swivel apparatus may comprise first and second axially spaced thrust bearing assemblies. When the mandrel and housing are in their first relative axial position axial load may transmitted between the housing and mandrel via the first thrust bearing assembly. When the mandrel and housing are in their second relative axial position axial load may be transmitted between the housing and mandrel via the second thrust bearing assembly.

The first thrust bearing assembly may be configured to accommodate axial loading between the mandrel and the housing in a first axial direction. The second thrust bearing assembly may be configured to accommodate axial loading between the mandrel and the housing in a second axial direction, wherein the second axial direction is opposite the first axial direction. In this respect, during swivel applications the housing and mandrel and may located in either their first or second axial positions based on the required direction of loading therebetween. For example, where tensile loading is required the housing and mandrel may be arranged in one of their first and second relative positions, and where compressive loading is required the housing and mandrel may be arranged in the other of their first and second relative positions.

The first and second thrust bearing assemblies may be defined as uni-directional thrust bearings.

In some examples, the relative axial movement required to reconfigure between the first and second relative axial positions may be advantageously utilised to provide a desired function, such as to provide tool actuation or the like, without hindrance from a dual direction bearing assembly.

The at least one thrust bearing assembly may be of any suitable form. The at least one thrust bearing assembly may comprise one or more bearing elements. In some examples the at least one thrust bearing assembly may comprise one or more rolling- based bearings comprising rolling bodies, such as balls, rollers and/or the like. The at least one thrust bearing assembly may comprise a bearing material, such as a low friction material, such as PTFE. The at least one thrust bearing assembly may comprise a hydraulic bearing assembly. In an example comprising first and second thrust bearing assemblies such bearing assemblies may be configured similarly or differently.

The at least one thrust bearing assembly may be defined, at least partially, by the mandrel. The at least one thrust bearing may be defined, at least partially, by the housing. Where first and second thrust bearing assemblies are provided at least one of the first and second thrust bearing assemblies may be defined, at least partially, by the mandrel. Similarly, at least one of the first and second thrust bearing assemblies may be defined, at least partially, by the housing.

The mandrel may comprise a first mandrel load shoulder and the housing may comprise a first housing load shoulder, wherein when the mandrel and housing are in their first relative axial position axial load may be transmitted between the first mandrel and housing load shoulders. In one example at least one thrust bearing assembly (such as a single thrust bearing assembly or a first thrust bearing assembly) may be interposed between the first mandrel and housing load shoulders. One or both of the first mandrel and housing load shoulders may form part of a thrust bearing assembly.

The mandrel may comprise a second mandrel load shoulder and the housing may comprise a second housing load shoulder, wherein when the mandrel and housing are in their second relative axial position axial load may be transmitted between the second mandrel and housing load shoulders. In one example at least one thrust bearing assembly (such as a single thrust bearing assembly or a second thrust bearing assembly) may be interposed between the second mandrel and housing load shoulders. One or both of the second mandrel and housing load shoulders may form part of a thrust bearing assembly.

At least one of the first and second load shoulders may comprise a terminating end of the mandrel and/or housing. At least one of the first and second load shoulders may comprise one or more annular faces formed on a stepped profile.

The first and second rotary connector portions may comprise rotary connecting profiles. The rotary connecting profiles may be configured for engagement and disengagement during relative axial movement between the mandrel and the housing. The rotary connecting profiles may become axially aligned and engaged when the housing and mandrel are in their third relative axial position, and disengaged when the housing and mandrel are moved away from the third relative axial position (for example when in the first or second relative axial position). Inter-engagement between the rotary connecting profiles may rotationally couple the mandrel and housing, and disengagement may permit rotational de-coupling.

The rotary connecting profiles may comprise complementary non-round profiles, such as oval profiles, eccentric profiles, hex-profiles and/or the like. In some examples the rotary connecting profiles may comprise cooperating splines. The rotary connecting profiles may comprise one or more keys and keyways.

The rotary connecting profiles may permit relative axial movement therebetween. This may facilitate relative movement of the mandrel and housing between the first and second relative axial positions, via the third relative axial position. In some examples the apparatus may comprise an alignment arrangement, configured to encourage or provide proper alignment between the rotary connecting profiles during relative axial movement between the mandrel and the housing towards the third relative axial position. Such an alignment arrangement may be provided in any suitable form, for example via a mule shoe arrangement or the like.

The swivel apparatus may comprise a retaining arrangement for axially connecting the mandrel and the housing in their third relative axial position. The retaining arrangement may facilitate axial loading to be transmitted between the mandrel and the housing when in their third relative axial position. Such axial loading capabilities may be in one or both axial directions. The retaining arrangement may provide a temporary axial connection between the housing and the mandrel when in their third relative axial position. That is, the retaining arrangement may be releasable. The retaining arrangement may be resettable. In some examples the retaining arrangement may be configured to provide a permanent connection between the mandrel and housing when in their third relative axial position. Such a permanent connection may be provided in accordance with user preference. That is, after a desired period of operation, which may include one or more cycles of relative axial movement between the first and/or second relative axial positions and the third relative axial position, the retaining arrangement may be used to provide the permanent axial connection, thus permanently locking the mandrel and housing in a rotary connection configuration. The retaining arrangement may be configured to automatically axially connect the mandrel and the housing when in their third relative axial position. That is, once the mandrel and housing reach their third relative axial position the retaining arrangement may function to axially connect the mandrel and housing.

The retaining arrangement may comprise a latch, for example a spring operated latch, pressure operated latch and/or the like.

The retaining arrangement may be releasable to permit subsequent relative axial movement between the mandrel and housing towards the first or second relative axial positions.

The retaining arrangement may be releasable in response to an axial load applied between the mandrel and housing reaching a pre-determined limit. That is, the retaining arrangement may be configured to hold axial loading applied between the mandrel and housing up to the pre-determined limit.

The retaining arrangement may be releasable by application of a pressure, for example by requiring a first pressure to hold the retaining arrangement in a lock position and a second pressure to release the retaining arrangement.

The retaining arrangement may comprise a j-slot mechanism, requiring a particular sequence of relative axial movement between the mandrel and housing to permit movement through the third relative axial position. In such an arrangement prior to completion of the sequence of relative axial movement the j-slot mechanism may temporarily axially connect the mandrel and the housing in their third relative axial position. Such axial connection may be in at least one axial direction.

The retaining arrangement may be configurable in an inactive state, such that the mandrel and housing may remain axially disconnected when in their third relative axial position. The retaining arrangement may be configurable in an active state, such that the mandrel and the housing may become axially secured together when in their third relative axial position. In this example, the housing and mandrel may be moved between their first and second relative axial positions without becoming axially secured in their third axial position, until such time as the retaining arrangement may be activated.

The retaining arrangement may be configurable in its active state by application of fluid pressure. In this case, when fluid pressure is applied the retaining arrangement may be considered to be primed. Fluid pressure may be established by developing a pressure differential between internal and external locations of the swivel apparatus.

The retaining arrangement may comprise a locking member axially fixed to one of the mandrel and the housing, and a locking profile on the other of the mandrel and the housing. The locking member may be radially moveable to be received in the locking profile when the mandrel and housing are in their third relative axial position. The retaining arrangement may comprise a retainer moveable between a locked position in which the locking member is retained in engagement with the locking profile, and an unlocked position in which the locking member is free to disengage the locking profile. The retainer may comprise a sleeve member. The retainer may radially constrain the locking member in engagement with the locking profile.

The retainer may be pressure operated. In this example the retainer may be configured in an inactive state when an actuation pressure is not applied, and in an active, or primed, state when pressure is applied. Such an actuation pressure may act to bias the retainer towards its locked position. In this example when the locking member and locking profile are misaligned and an actuation pressure is applied against the retainer, the retainer may be prevented from moving towards its locked position by engagement with the locking member. In this case the retainer may immediately shift to its locked position when the locking member and profile become axially aligned (i.e. , in the third relative axial position). Removal or reduction of the actuation pressure may permit the retainer to shift to its unlocked position, such that relative axial movement between the mandrel and the housing may again be permitted.

The retainer may be biased in a desired direction. In one example the retainer may be biased towards its unlocked position. The retainer may be spring biased.

The retaining arrangement may comprise a permanent lock mechanism, such as a ratchet mechanism, snap ring and/or the like. In one example the permanent lock mechanism may be pressure operated. For example, the permanent lock mechanism may be held against movement or operation by a shearing arrangement, wherein when a threshold pressure is reached the shearing arrangement may be sheared to permit the permanent lock mechanism to be moved to a permanent lock position. In one example the permanent lock mechanism may be acted on and shifted by the retainer.

In the example where the retaining arrangement is pressure operated it should be understood that this does not necessarily mean that the swivel apparatus is reconfigured between its first, second and third relative positions. Rather, such reconfiguring may be made via relative axial movement between the mandrel and housing, for example achieved via mechanical manipulation, with the pressure operation being restricted only to the operation of the retaining arrangement to provide a locking function in the third relative axial position.

The locking member may comprise a locking dog. The locking profile may comprise a recess.

The retaining arrangement may be operated via a dropped object, such as a dart, ball and/or the like. The retaining arrangement may be wireline operated or the like.

The swivel apparatus may comprise a contingency locking mechanism configured to provide axial locking of the mandrel and housing when in their third relative axial position. In some examples the contingency locking mechanism may be operated via a dropped object, wireline, pressure and/or the like.

The swivel apparatus may comprise a rotary drive mechanism to permit a rotary drive to be transmitted to a separate apparatus, such as a separate tool, for example a pump, jarring tool, packer, anchor tool and/or the like. The rotary drive mechanism may comprise a telescoping arrangement, permitting a rotary connection to be achieved without compromising the ability for the mandrel and housing to be moved axially relative to each other. The telescoping arrangement may comprise a spline arrangement, key and key-way arrangement and/or the like.

The mandrel may comprise the rotary drive mechanism. In this example rotation of the mandrel, for example via a rotating work string, may be translated to a separate apparatus, irrespective of whether the swivel apparatus is in a swivelling configuration or a rotary locked configuration.

The mandrel may be axially moveable to provide relative axial movement between the mandrel and the housing. The housing may be axially moveable to provide relative movement between the mandrel and the housing. Both the mandrel and the housing may be axially moveable to provide relative rotation therebetween.

An aspect of the present disclosure relates to a downhole method, comprising: running a swivel apparatus into a wellbore, wherein one of a mandrel and a housing of the swivel apparatus is connected to a rotating string and the other of the mandrel and the housing are connected to wellbore apparatus; locating the mandrel and the housing in one of a first and second relative axial position such that the mandrel and housing are rotatable relative to each other to permit the rotating string to be rotated relative to the wellbore apparatus; and locating the mandrel and the housing in a third relative axial position which is intermediate the first and second relative axial positions such that the mandrel and housing are rotatably coupled to permit the rotating string to rotate the wellbore apparatus.

An aspect of the present disclosure relates to a method for running wellbore apparatus into a wellbore, comprising: connecting one of a mandrel and a housing of a swivel apparatus to a rotating string; connecting the other of the mandrel and the housing to the wellbore apparatus; deploying the swivel apparatus and connected wellbore apparatus into the wellbore on the rotating string; location the mandrel and the housing in one of a first and second relative axial position such that the mandrel and housing are rotatable relative to each other to permit the rotating string to be rotated relative to the wellbore apparatus; and locating the mandrel and the housing in a third relative axial position which is intermediate the first and second relative axial positions such that the mandrel and housing are rotatably coupled to permit the rotating string to rotate the wellbore apparatus. The wellbore apparatus may comprise any apparatus, equipment, tool etc. In some examples the wellbore apparatus may comprise casing, liner, sand screen, a downhole tool, a jarring apparatus and/or the like.

An aspect of the present disclosure relates to a swivel apparatus, comprising: a housing; a mandrel extending within the housing; wherein the mandrel and the housing are axially moveable relative to each other between a swivel configuration in which the mandrel and housing are rotatable relative to each other and a rotary locked configuration in which the mandrel and housing are rotatable relative to each other, the swivel apparatus further comprising: a retaining arrangement for axially connecting the mandrel and the housing in the rotary locked configuration.

Features defined in relation to any aspect above may be provided in combination with the swivel apparatus of the present aspect. For example, the retaining arrangement defined in any other aspect may be provided as the retaining arrangement in the present aspect.

An aspect of the present disclosure relates to a retaining arrangement for use in a downhole apparatus, the retaining arrangement provided in accordance with any disclosure above.

An aspect of the present disclosure relates to a swivel apparatus for use in a wellbore, comprising: a housing comprising a first rotary connector portion; a mandrel extending within the housing and comprising a second rotary connector portion; first and second axially spaced thrust bearing assemblies; wherein the mandrel and the housing are axially moveable relative to each other between: a first relative axial position in which the mandrel and housing are rotatable relative to each other and axial load is transmitted between the housing and mandrel via the first thrust bearing assembly; a second relative axial position in which the mandrel and housing are rotatable relative to each other and axial load is transmitted between the housing and mandrel via the second thrust bearing assembly; and a third axial position, intermediate the first and second axial positions, in which the first and second rotary connector portions are engaged to rotatably connect the housing and mandrel relative to each other.

An aspect of the present disclosure relates to a swivel apparatus for use in a wellbore, comprising: a housing comprising a first rotary connector portion; a mandrel extending within the housing and comprising a second rotary connector portion; wherein the mandrel and the housing are axially moveable relative to each other between: first and second relative axial positions in which the first and second rotary connectors are disengaged and the mandrel and housing are rotatable relative to each other; and a third axial position, intermediate the first and second axial positions, in which the first and second rotary connector portions are engaged to rotatably connect the housing and mandrel relative to each other.

Features defined in relation to one aspect may be provided in combination with any other aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is cross-sectional view of an example swivel apparatus in a first swivel configuration;

Figure 2 is a cross-sectional view of the swivel apparatus in Figure 1 in a second swivel configuration; Figure 3 is an enlarged view of region A of Figure 2, showing a retaining arrangement in a primed state;

Figure 4 illustrates the retaining arrangement of Figure 3 in a temporary locked state;

Figure 5 illustrates the retaining arrangement of Figure 3 in a permanently locked state;

Figure 6 is an enlarged view of a contingency locking mechanism of the swivel apparatus of Figure 1;

Figure 7 to 9 illustrate the sequential operation of an alternative retaining mechanism

Figures 10 to 12 illustrate the sequential operation of an alternative form of a retaining mechanism;

Figures 13 to 15 diagrammatically illustrate the configuration of a j-slot mechanism in Figures 10 to 12, respectively;

Figures 16 and 17 are cross-sectional views of a portion of an alternative swivel apparatus in respective first and second swivel configurations; and

Figure 18 is a cross-sectional view of an alternative swivel apparatus.

DETAILED DECRIPTION OF THE DRAWINGS

A swivel apparatus, generally identified by reference numeral 10, is shown in cross- section in Figure 1. The apparatus 10 comprises a housing 12 and a mandrel 14 which extends into the housing 12, wherein the housing 12 and mandrel 14 are capable of being moved axially relative to each other between different positions or configurations in which relative rotation between the housing 12 and mandrel 14 is either permitted or prevented, as will be described in detail below.

The housing 12 includes a lower connector 16 (pin connector in this example) for connecting to wellbore apparatus (not shown), such as casing, liner, downhole tools, sand screen etc. The mandrel 14 includes an upper connector 18 (box connector in this example) for connecting to a rotary string (not shown), for example a work string, drill string etc. In this case the swivel apparatus 10 may be operated to selectively prevent and permit torque to be transmitted between the rotary string and wellbore apparatus.

The housing 12 includes first and second axially spaced (i.e., upper and lower) housing load shoulders 20, 22, and the mandrel 14 defines corresponding first and second axially spaced (i.e., upper and lower) mandrel load shoulders 24, 26. A first thrust bearing assembly 28 is mounted on the housing 12 adjacent the first housing load shoulder 20, and a second thrust bearing assembly 30 is mounted on the housing 12 adjacent the second housing load shoulder 22. In an alternative example one or both of the first and second thrust bearing assemblies 28, 30, or one or more components thereof, may be mounted on the mandrel 14. Further, one or both of the first and second housing and mandrel load shoulders 20, 22, 24, 26 may be considered to form part of an associated thrust bearing assembly 28, 30. The thrust bearing assemblies 28, 30 may be of any form suitable to accommodate both axial load and rotation. For example, roller bearings, low friction bearing materials etc. may be utilised.

The housing 12 comprises a first rotary connector portion in the form of a first splined profile 32, and the mandrel 14 comprises a complimentary second rotary connector portion in the form of a second splined profile 34. As will be described in detail below, when the first and second splined profiles 32, 34 are axially aligned the housing 12 and mandrel 14 become rotatably connected, and when the first and second splined profiles 32, 34 are axially misaligned the housing 12 and mandrel 14 become rotatably disconnected.

The swivel apparatus 10 further comprises a retaining arrangement 36 which, when activated, functions to axially retain the housing 12 and mandrel 14 in a rotatably connected configuration, as will be described in detail below.

The swivel apparatus 10 further comprises a contingency locking mechanism 37 which will be described in more detail below.

The swivel apparatus 10 is illustrated in Figure 1 with the housing 12 and mandrel 14 located in a first relative axial position, in which the first mandrel load shoulder 24 is in engagement with the first thrust bearing assembly 28 such that axial load may be transmitted between the housing 12 and mandrel 14. Such axial load may be applied by pulling tension within the connected rotary string and/or by virtue of the weight of the housing 12 and connected wellbore apparatus (for example during deployment of the wellbore apparatus into the wellbore). When the housing 12 and mandrel 14 are in the illustrated first relative axial position the first and second splined profiles 32, 34 are disengaged such that relative rotation between the housing 12 and mandrel 14 is permitted, such that the connected rotary string and wellbore apparatus are rotationally decoupled. This configuration may be defined as a first swivel configuration. This rotary decoupling may permit the rotary string to be rotated for a number of reasons (reducing running friction tool operation etc.) without requiring corresponding rotation of the connected wellbore apparatus, which may not be desirable.

Figure 2 illustrates the swivel apparatus 10 with the housing 12 and mandrel 14 located in a second relative axial position, in which the second mandrel load shoulder 26 is in engagement with the second thrust bearing assembly 30 such that axial load may be transmitted between the housing 12 and mandrel 14. Such axial load may be applied by setting weight down on the connected wellbore apparatus, which may thus create a compressive load between the housing 12 and mandrel 14. Such a compressive load might be required to effectively push the wellbore apparatus further into the wellbore, for tool actuation purposes and/or the like. When the housing 12 and mandrel 14 are in the illustrated second relative axial position the first and second splined profiles 32, 34 are still disengaged such that relative rotation between the housing 12 and mandrel 14 is permitted, such that the connected rotary string and wellbore apparatus are also rotationally decoupled. This configuration may be defined as a second swivel configuration.

It should be noted that in order to reconfigure the apparatus from the first swivel configuration of Figure 1 to the second swivel configuration of Figure 2, relative axial movement between the housing 12 and mandrel 14 is such that the first and second splined profiles 32, 34 will temporarily be engaged. However, in the present example of Figures 1 and 2 the retaining arrangement 36 is in a dormant or deactivated state, such that free relative axial movement of the first and second splined profiles 32, 34 is possible during the transition between the first and second swivel configurations. The retaining arrangement 36 will now be described in detail with reference to Figure 3 which is an enlarged view of region A of Figure 2. The retaining arrangement 36 comprises a plurality of circumferentially arranged locking keys 38 which are axially secured in respective radial slots 40 formed in a key carrier sleeve 42 secured to or forming part of the housing 12. The mandrel 14 comprises a locking recess 43 in an outer surface thereof, wherein the locking keys 38 may be received within the locking recess 43 when aligned therewith. The retaining arrangement 36 further comprises a retainer sleeve 44 which is biased in the direction of arrow 46 by spring 48 towards an unlocked position. The retainer sleeve 44 defines a key recess 50 which receives the keys 38 when said keys 38 are misaligned from the locking recess 43. In other examples, a separate component may be provided to define the key recess 50. When the retaining arrangement 36 is deactivated, relative movement between the housing 12 and mandrel 14 will align the keys 38 with the locking recess 43 but an axial connection will not be established in that the keys 38 are not radially constrained and as such will be merely be driven out of the locking recess during continued relative motion between the housing 12 and mandrel 14.

The retainer sleeve 44 defines a differential piston which includes a first sealing area 54 engaged with a first inner diameter of the housing 12 and a second sealing area 56 engaged with a second larger inner diameter of the housing 12. An annular space 58 is defined between the first and second sealing areas and is in pressure communication with a space external to the swivel apparatus 10 via port 60. The opposite sides of the sealing areas 54, 56 are exposed to pressure internally of the swivel apparatus 10, for example via ports 62.

The retaining arrangement 36 further comprises a shear sleeve 64 located within the annular space 58 and initially secured to the housing 12 via a number of shear screws 66. The purpose and functionality of the shear sleeve 64 will be described later.

When an operator requires the housing 12 and mandrel 14 to become rotatably secured together the retaining arrangement 36 is activated in the following manner. A pressure differential is applied between internal and external locations of the swivel apparatus 10, applying a net force on the differential piston of the retainer sleeve 44 in the direction of arrow 68, shifting the retainer sleeve 44 in the same direction until a tapered edge 67 of the key recess 50 engages the keys 38. Further movement of the retainer sleeve 44 is thus prevented. In this condition the retaining arrangement 36 may be defined as being in a primed state.

The housing 12 and mandrel 14 may then be moved axially relative to each other until the locking recess 43 of the mandrel 14 becomes aligned with the locking keys 38, as illustrated in Figure 4, at which point the keys 38 will be driven into the locking recess 43 by the retainer sleeve 44 which is still under the effect of the differential pressure, with the stroke of the retainer sleeve 44 being limited by engagement with the shear sleeve 64. In this configuration the locking keys 38 become radially constrained by the retainer sleeve 44, thus effectively axially locking the housing 12 and mandrel 14 together at a relative axial position, which may be defined as an intermediate third relative axial position, in which the first and second splined profiles 32, 34 are engaged. As such, the housing 12 and mandrel 14 are both rotatably and axially locked together allowing both axial load and torque to be transmitted though the swivel apparatus 10.

The housing 12 and mandrel 14 may become unlocked again by relieving the pressure differential, allowing the spring 48 to return the retainer sleeve 44 to a position in which the locking keys 38 become aligned with the key recess 50, allowing disengagement from the locking recess 43 in the mandrel 14. However, if an operator requires the rotary and axial connection between the housing 12 and mandrel to be made permanent, the pressure differential may be increased to cause the shear screws 66 to be sheared and allow the retainer sleeve 44 to be further moved in the direction of arrow 68, as illustrated in Figure 5, until a snap ring 70 is received within a groove 72, preventing further operation of the retainer sleeve 44.

If the retaining arrangement 36 is compromised for any reason an operator may use the contingency locking mechanism 37, which will now be described with reference to the enlarged view of Figure 6. The mandrel 14 includes a number of contingency keys 80 extending through respective radial slots 82, and the housing 12 includes an inner key recess 84, wherein the keys 80 and recess 84 become axially aligned when the first and second splined profiles 32, 34 are engaged. The contingency locking mechanism 37 further comprises a seat sleeve 86 which is configured to receive a dropped object 88 (a dart is used in the present example although any dropped object such as a ball may be used). When the keys 80 and recess 84 are aligned, as illustrated in Figure 6, the dropped object 88 will drive the seat sleeve 86 to cause the keys 80 to be radially extended and received in the recess 84, thus axially locking the housing 12 and mandrel 14 together. In alternative examples the contingency locking mechanism 37 may be operated by any other suitable means, such as via wireline, coiled tubing, and/or the like.

In the example presented above a pressure operated retaining arrangement 36 is provided. However, this is merely optional and any suitable retaining arrangement may be utilised. One further example is illustrated in Figure 7, which illustrates a portion of the same swivel apparatus 10 defined above, but incorporating an alternative retaining arrangement 136.

The retaining arrangement 136, in a similar manner to that described above, includes a plurality of locking keys 138 axially constrained in radial slots 140 formed in a key carrier sleeve 142 secured to the housing 12. A locking recess 143 is formed in an outer surface of the mandrel 12, wherein when the housing 12 and mandrel 14 are in the illustrated first relative axial position, with the first and second spline profiles 32, 34 disengaged, the locking recess 143 is misaligned from the locking keys 138. The retaining arrangement 136 further comprises a latch sleeve 144 which is biased by an axial spring 148 in the direction of arrow 146. The latch sleeve 144 includes a tapered edge surface 90 which engages corresponding respective tapered edge surfaces 92 of the locking keys 138, such that the axial bias force provided by the spring 148 resolves to an inwardly radial bias applied on the locking keys 138 by virtue of the cooperating tapered edges 90, 92.

In use, when the housing 12 and mandrel 14 are moved from the first relative axial position of Figure 7 to an intermediate or third relative axial position as illustrated in Figure 8, the first and second splined profiles 32, 24 become engaged and the locking recess 143 becomes aligned with the locking keys 138 which are driven under the action of the biased latch sleeve 144 into the locking recess 143, thus providing a degree of axial locking. This is also the case when the housing 12 and mandrel 14 are moved from the second relative axial, illustrated in Figure 9, to the intermediate or third relative axial position illustrated in Figure 8.

The locking recess 143 defines a tapered profile 94 such that when it is required to disengage the first and second splined profiles 32, 34, axial load applied between the housing 12 and mandrel 14 will force the locking keys 138 radially outwardly, against the bias provided by the latch sleeve 144. When the applied axial load resolves to exceed the bias provided by the spring the locking keys 138 will be displaced from the locking recess 143, allowing relative axial movement between the housing 12 and mandrel 14, for example towards their second relative axial position as illustrated in Figure 9.

Thus, the retaining arrangement 136 may be defined as passive, in that initial activation is not required.

A further example of a retaining arrangement, generally identified by reference number 236, will now be described initially with reference to Figure 10, which illustrates the same swivel apparatus 10 first shown in Figure 1, in combination with the alternative retaining arrangement 236. In this example the retaining arrangement 236 is in the form of a j-slot mechanism and includes a pin 100 secured to the housing 12 and a track 102 rotatably mounted about the mandrel 14, wherein the track 102 defines a confined travel path for the pin 100. In other examples the pin may be provided on the mandrel 14 and the track on the housing 12. Further, in the present example multiple pins 100 and tracks 102 are provided.

When the swivel apparatus 10 is in its first swivel configuration, illustrated in Figure 10, the pin 100 is arranged relative to the track 102 in the manner diagrammatically illustrated in Figure 13. When the swivel apparatus 10 is to be configured in its second swivel configuration, illustrated in Figure 11, the housing 12 and mandrel 14 are moved axially relative to each other, for example by setting weight down through the swivel apparatus 10, to progress the pin 100 along the track to the configuration illustrated in Figure 14.

When the swivel apparatus 10 is to be configured in a rotary locked configuration, illustrated in Figure 12, the housing 12 and mandrel 14 are moved axially relative to each other, for example by applying tension or a pulling force via a connected rotary string, to locate the pin 100 relative to the track 102 in the manner diagrammatically illustrated in Figure 15. In the configuration of Figure 14, a degree of axial (e.g. tensile) load between the housing 12 and mandrel 14 may be carried through the retaining arrangement 236. The housing 12 and mandrel 14 may be reconfigured between their various positions in an endless manner by appropriate sequences of relative axial movement in accordance with the control of the j-slot mechanism.

An alternative swivel apparatus, generally identified by reference numeral 310, is illustrated in Figure 16. In this case the swivel apparatus 310 is similar in many respects to apparatus 10 and as such like feature share like reference numerals, incremented by 300, with a further detailed description not provided for brevity. In view of the similarities between apparatus 310 and apparatus 10, only a lower portion of the apparatus 310 is illustrated in Figure 16, with the upper portion being of identical form to that in apparatus 10 first shown in Figure 1.

In the present example the mandrel 314 is configured to provide a rotary drive connection to a separate apparatus (not shown). The apparatus 310 comprises a telescoping torque transmission assembly 104 which includes a torque sleeve 106 axially fixed relative to the housing and extending through a second thrust bearing assembly 330 and terminating in a rotary connector 108 for connecting to the separate apparatus. The torque transmission assembly 104 further includes a plurality of torque keys 110 secured to the torque sleeve 106 and which are received in respective elongate keyways 112 formed in a lower end of the mandrel 314. A terminating end of the mandrel 314 also defines a load shoulder 326.

The apparatus 310 is located in its first swivel configuration in Figure 16, such that the load shoulder 326 of the mandrel 314 is disengaged from a corresponding load shoulder 114 formed on the torque sleeve 106, which is engaged with the second thrust bearing assembly 330. When the apparatus 310 is reconfigured into its second swivel configuration, illustrated in Figure 17, relative axial movement between the housing 312 and mandrel 314 is permitted by the telescoping torque transmission assembly 104, with such relative axial movement being permitted until engagement between load shoulder 326 of the mandrel and load shoulder 114 of the torque sleeve, loading the second thrust bearing assembly 330.

An alternative swivel apparatus, generally identified by reference numeral 410, is illustrated in Figure 18. The swivel apparatus 410 is similar in many respects to apparatus 10 and as such like feature share like reference numerals, incremented by 400. IN view of the similarities a full description of every feature of apparatus 410 will not be provided for brevity reasons, on the understanding that this can be derived and understood from the description of apparatus 10 provided above. However, a primary distinction between apparatus 410 and apparatus 10 first shown in Figure 1 is the provision of a unitary or single thrust bearing assembly, which will now be described.

The apparatus 10 includes a housing 412 having first and second axially spaced housing load shoulders 420, 422 with a single thrust bearing 29 interposed and captivated therebetween. The apparatus 10 further comprises a mandrel 414 which defines corresponding first and second axially spaced mandrel load shoulders 424, 426. The apparatus 410 is illustrated in Figure 18 in an intermediate position such that rotary connecting splined profiles 432, 434 provided on the housing 412 and mandrel 414 are engaged, thus rotatably locking the housing 412 and mandrel 414 together, with a separate retaining mechanism 436 operated to provide a corresponding axial connection. When in this configuration both load mandrel load shoulders 424, 426 are spaced from the thrust bearing assembly 29.

When a swivel operation with tensile loading is required the housing 412 and mandrel 414 are axially moved relative to each other bring the first mandrel load shoulder 424 into engagement with the thrust bearing 29, while at the same time disengaging the rotary connecting splined profiles 432, 434. When a swivel operation with compressive loading is required the housing 412 and mandrel 414 are axially moved relative to each other to bring the second mandrel load shoulder 426 into engagement with the thrust bearing 29, while at the same time disengaging the rotary connecting splined profiles 432, 434.

It should be understood that the examples provided herein are indeed exemplary of the present disclosure, and that various modifications may be possible.