CA2923182A1 - Latching assembly - Google Patents

Abstract

A latching assembly has a tubular housing having an outer surface and an inner surface that defines an inner bore. Latch members are carried by the housing that have a latch position that extends out from the outer surface and a release position that is retracted from the latch position. A plurality of gripping members are pivotally attached to the housing. The gripping members are pivotally attached to the tubular housing and move between a gripping position wherein the gripping members extend into the inner bore and a retracted position. An actuator engages the latch members and the gripping members and moves between a first position and a second position. The actuator moves the latch members from the latch position to the release position and the gripping members from the retracted position to the gripping position as the actuator moves from the first position to the second position.

Description

TITLE
[0001] Latching assembly FIELD

[0002] This relates to a latching assembly, such as a latching assembly that may be used to latch a rotating control device with a riser.
BACKGROUND

[0003] Rotating control devices are often used in order to manage pressure when drilling offshore. The rotating control device is generally secured to a riser by way of a removable latch in order to simplify installation and removal. United States patent no.
7,487,837 (Bailey et al.) entitled "Riser Rotating Control Device" describes a latching assembly that connects to a riser, and that can be released remotely.
SUMMARY

[0004] There is provided a latching assembly, comprising a tubular housing having an outer surface and an inner surface that defines an inner bore. Latch members carried by the housing have a latch position that extends out from the outer surface and a release position that is retracted from the latch position. A plurality of gripping members are pivotally attached to the housing, the gripping members having a first end that is pivotally attached to the tubular housing and a second end extending outward from the first end. The gripping members pivotally move between a gripping position wherein the second end of the gripping members extend into the inner bore to engage a tubular member and a retracted position. An actuator engages the latch members and the gripping members and moves between a first position and a second position, the actuator engaging the latch members and the gripping members such that the actuator moves the latch members from the latch position to the release position and the gripping members from the retracted position to the gripping position as the actuator moves from the first position to the second position.

[0005] According to another aspect, the latching assembly may further comprise a first locking element that moves between a locked position to secure the latch members in the latch position, and a release position to release the latch members from the latch position.

[0006] According to another aspect, the actuator may be an electrical actuator.

[0007] According to another aspect the latching assembly may further comprise a second locking mechanism that moves between a locked position to secure the latch members in the release position, and a release position to release the latch members from the release position.

[0008] According to another aspect, the latch members may comprise a spring element that biases the latch members toward the release position.

[0009] According to another aspect, the latching assembly may further comprise a secondary release element that slides axially along the housing and is connected to the actuator such that, when actuated, the secondary release element moving the actuator from the first position to the second position.

[0010] According to another aspect, the first end of the gripping members may comprise a first pivotal connection that connects the gripping members and the actuator and a second pivotal connection spaced along the gripping members from the first pivotal connection, the second pivotal connection that connects the gripping members and the housing and the actuator moving radially such that the actuator moves the gripping members between the gripping position and the release position.

[0011] According to another aspect, the first end of the gripping members may comprise a cam surface that engages the actuator, the actuator moving axially along the housing and applying a force to the cam surface to rotate the gripping members between the gripping position and the release position.

[0012] According to another aspect, the actuator may comprise a first portion that moves axially along the housing and a second portion that moves radially within the housing, the first portion engaging the second portion by a sloped engagement surface such that the axial movement of the first portion results in the radial movement of the second portion.

[0013] According to another aspect, there is provided, in combination, a riser defining a central bore, a drill string extending through the riser, and a latching assembly as described above positioned within the central bore of the riser and receiving the drill string within the central bore of the housing of the latching assembly. A sealing and bearing assembly is mounted to the drill string and attached to the latching assembly.

[0014] The aspects described above may be combined together in any reasonable combination. Other aspects will become apparent from the description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:
FIG. 1 is a side elevation view in section of a latching assembly in a released position.
FIG. 2 is a side elevation view in section of a latching assembly in a latched position.
FIG. 3 is a side elevation view in section of a latching assembly in a released position with a running tool positioned within the assembly.
FIG. 4 is a side elevation view in section of a latching assembly and the running tool expanded to engage the assembly.
FIG. 5 is a side elevation view in section of the latching assembly being actuated toward a release position.
FIG. 6 is a side elevation view in section of the latching assembly in a released position.
FIG. 7 is a side elevation view of a latching assembly securing a bearing assembly in a riser.
FIG. 8 is a side elevation view in section of a latching assembly securing a bearing assembly in a riser.
FIG. 9 is a top plan view of an alternative latching assembly in a latched position.
FIG. 10 is a side elevation view of an alternative latching assembly in a latched position.
FIG. 11 is a side elevation view in section of an alternative latching assembly in a latched position.
FIG. 12 is a side elevation view in section of an alternative latching assembly in a release position.
FIG. 13 is a side elevation view in section of an alternative latching assembly in a manually released position.
FIG. 14 is a side elevation view in section of an alternative latching assembly in a latching position FIG. 15 is a side elevation view in section of the alternative latching assembly of FIG. 14 in a release position.
DETAILED DESCRIPTION

[0016]
Referring to FIG. 7 and 8, a latching assembly 100 is used to secure a bearing assembly 102 to a riser 104. Riser 104 has a port 106 that is designed to be attached to a conduit (not shown) for pumping fluids, such as drilling mud. Bearing assembly 102 may include a bearing section and a seal section, which may be separate or integrally formed. The actual configuration of bearing assembly 102 will vary depending on the preferences of the user and the demands of the situation. As can be seen, latching assembly 100 preferably carries bearing assembly 102 and latches to riser 104. While latching assembly 100 and bearing assembly 102 are shown as separate components, they may be integrally formed, depending on the space requirements and preferences of the user. During normal operation, latching assembly 100 and bearing assembly 102 support a tubular 108, such as a drill string, that passes through each assembly 100 and 102 and through one or more seals 110. Bearing assembly 102 may be removed by unlatching latching assembly 100, and pulling bearing assembly 102 to surface. As latching assembly 100 is removed with bearing assembly 102, it can be serviced at the same time as bearing assembly 102. Referring to FIG. 9 and 10, the latches can be seen extending from latching assembly 100.

[0017]
Referring to FIG. 1 and 2, details of the latching assembly are shown. The example shown in FIG. 1 ¨ 6 has the following elements indicated by reference numbers:
11 ¨ housing 12 ¨ bottom cap 13 ¨ unlock sleeve 14 ¨ shear pin 15 ¨ latch lock ring 16 ¨ latch lock ring pin 17 ¨ latch lock ring guide pin

18 ¨ latch lock ring return spring

19 ¨ latch lock ring electrical device

20 ¨ unlatch lock ring

21 ¨ unlatch lock ring guide pin

22 - unlatch lock ring spring 5 23 - unlatch lock ring electrical device 24 ¨ latch segment 25 ¨ latch shaft 26 ¨ latch spring 27 ¨ latch electrical device 28 ¨ latch shaft o-ring 29 ¨ unlock sleeve segment 30 ¨ unlock sleeve segment pin 31 ¨ unlock sleeve fulcrum pin 32 ¨ retrieval arm 33 ¨ retrieval arm anchor pin 34 ¨ electrical device mount bolt 35 ¨ self control power source (SCPC)-1 36 ¨ self control power source (SCPC)-2 37 ¨ wireless device 38 ¨ unlock sleeve o-ring 39 ¨ bottom cap o-ring 40 ¨ bottom cap bolts 41 ¨ unlatch running tool [0018] Referring to FIG. 1, there is a tubular housing 11 with an outer surface 50 and an inner surface 52 that defines an inner bore 54. A latch 24 is carried by the housing 11 that has a latch position as shown in FIG. 2 extending out from the outer surface and a release position as shown in FIG. 1 retracted from the latch position, preferably flush with or recessed from the outer surface 50 of the housing 11, but in any event, sufficiently retracted to disengage from the corresponding groove or aperture in the riser (not shown). An electrical actuator 27, such as an electromagnet, moves the latch 24 between the latch position and the release position. The electrical actuator 27 may take other forms as well, and may apply forces in either direction, depending on the signal being transmitted. Alternatively and as shown, the latch 27 may be biased by a spring 26 or other resilient member, toward the unlatched position as shown, or the latched position in other embodiments, such that the electrical actuator 27 merely applies a force to move the latch to the other position.
[0019] The latch 24 is secured by a first locking element 15 that moves between a locked position to secure the latch 24 in the latch position as shown in FIG. 2, and a release position to release the latch 24 from the latch position as shown in FIG. 1. As shown, the first locking element 15 is a latch lock ring. Latch lock ring 15 may take other forms, and may be made up of one or more components. Preferably, a second locking element 20 is also provided, shown as a unlatch lock ring, which has a locked position that secures the latch 24 in the release position as shown in FIG. 1, and a release position that permits the latch to move between the latched and the unlatched positions as shown in FIG. 2 - 6. As depicted, the locking elements 15 and 20 move perpendicular to the direction of travel by the latch 24. As with the latch 24, each locking element 15 and 20 may be powered by an electrical actuator in either both directions, or only one direction with a biasing element, such as a spring, that biases the locking element toward the other position. As shown, first locking element 15 is moved to a retraced position by an electromagnet 19 and is biased toward an extended position by a spring 18 while second locking element 20 is moved to a retraced position by an electromagnet 27 and is biased toward an extended position by a spring 22.
[0020] The latch 24 and the locking elements 12 and 20 are preferably powered by an onboard power source 35 or 36 that is carried by the housing 11, such as a battery pack, and are preferably controlled by a wireless controller 37 that is programmed to control the position of the latch 24, the first locking element 15 and the second locking element 20 based on signals received from a controller (not shown), such as a computer located at an operator's station. The combination of the onboard power source 35 and 36 and the wireless communicator 37 allow the latching assembly 100 to operate without any umbilicals running to the assembly 100.

[0021]
Referring to FIG. 3 ¨ 6, in addition to the latch 24 described above, the latching assembly 100 also preferably includes a tubular gripping assembly as well as a secondary release mechanism.
[0022] The latching assembly 100 has a cantilevered gripping member 32 that is positioned within the inner bore 54 of the housing 11. The gripping member 32 is connected to the housing 11 by a movable connection such as fulcrum pin 31, and is also preferably connected to the latch 24. As depicted in FIG. 1, as the latch 24 moves toward the release position, the latch 24 pushes out on the cantilevered gripping member 32, causing it to pivot about the movable connection 31 and therefore extend into the inner bore 54, allowing it to engage a tubular member (not shown), such as a drill string or running tool.
Depending on the tolerances and the actual movement of the various component, it will be understood that the movable connection 31 or the engagement of the latch 24 may require some lateral movement as well as pivoting movement to accommodate the movement of the latch 24. The cantilevered gripping arm 32 may be used to grip, for example, a joint of a tubular member such as a drill string or a portion of a running tool, etc. that has an enlarged radius or other gripping surface.

[0023]
Referring to FIG. 3 ¨ 6, the secondary release element 29 is also connected to move with the latch 24 and is engaged by a collar or unlock sleeve 13 that is slidably engaged within the inner bore 54 of the housing 11. As shown, the secondary release element 29 is secured to the inward end of the latch 24 and extends downward opposite the cantilevered gripping arm 32 in the depicted example. The collar 13 engages the secondary release element 29 as it is raised and applies a force to move the latch 24 to the release position. As shown, the collar 13 is preferably engaged by a running tool 56 that engages the collar 13, such as by expanding outward to become secured within an inner profile 58 of the collar 13 as shown in FIG. 4, which allows an upward force to be applied to the collar 13 to engage the secondary release element 29, as shown in FIG. 5. The collar 13 and the secondary release element 29 preferably have complementary sloped surfaces, such that, as the collar 13 is raised, the slopes are engaged, and a force is applied to release the latch 24 as shown in FIG.
6, which also moves the gripping members 32 of the tubular gripping assembly to engage the running tool 56. In this position, the latching assembly is locked into the release position and is securely attached to the running tool 56 and can therefore be safely removed. The secondary release element 29 may be useful if the latch 24 becomes stuck in the latched position due to a buildup of debris, mechanical or electrical failure, etc. It may also be used as a secondary lock against the latch 24 moving to the latched position during removal, and in the depicted example, helps maintain the cantilevered gripping arm in the gripping position.

[0024] A preferred example of a latching assembly will now be described with respect to FIG. 1 - 6. The assembly 100 is designed to operate a mechanical latching and retrieval assembly via remote control without the aid of umbilical lines or power cables. In this example, the assembly is preferably powered by a self-contained power source.
The mechanical latch assemblies are operated by an electrical device, where the direction in which the latches are operated is determined by the polarity the current is applied to the electrical device. The assembly is controlled by a wireless device inside the housing, and the wireless device is controlled by a stand-alone workstation situated elsewhere, such as at surface. The operation of this preferred example of the device will now be given, with reference to the drawings.

[0025] Referring to FIG. 1 and 2, the initial latching procedure of the depicted example will now be described:
1. Signal is sent to wireless device 37 via remote work station 2. Wireless device 37 sends signal to electrical device 27 which receive power from self-contained power source 35 3. Electrical device 27 moves latch shaft 25 which is connected to latch segment 24, which is pushed outwards from housing 1 into the lock position, from the position shown in FIG. 1 to the position shown in FIG. 2.
4. Latch lock ring 15 is moved by electrical device 19 and with the aid of latch lock ring spring 18 into lock position behind latch shaft 25, as shown in FIG.

2.

[0026] Referring to FIG. 5 and 6, the unlatching procedure will now be described:

1. Signal is sent to wireless device 37 via remote work station 5. Wireless device 37 sends signal to electrical device 19 which receive power from self-contained power source 35 2. Latch lock ring 15 is moved out of lock position behind latch shaft 25.
3. Electrical device 27, which receives power from self-contained power source 35 moves latch shaft 25 and latch segment 14 that is attached with the aid of latch springs 26 into the unlatched position.
6. Electrical device 23 which receive power from self-contained power source moves unlatch lock ring 20 with the aid of unlatch lock ring spring 22 into the lock position in front of latch shaft 25

[0027] Referring to FIG. 5 and 6, the procedure for extending the retrieval arm will now be described:
1. Signal is sent to wireless device 37 via a remote work station 2. Electrical device 27, which receives power from self-contained power source 35 moves latch shaft 25 and latch segment 24 that is attached with the aid of latch springs 26 into the unlatch position 3. Latch shaft 25 pushes unlock sleeve segment pin 30 with attached unlock sleeve segment 29 which pushes unlock sleeve fulcrum pin 31 which pushes retrieval arm 32 and forces it to pivot outwards due to retrieval arm anchor pin

[0028] Referring to FIG. 5 and 6, the procedure for retracting the retrieval arm will now be described:
1. Signal is sent to wireless device 37 via remote work station 2. Electrical device 23, which receives power from self-contained power source 35, moves unlatch lock ring 20 into the unlock position below latch shaft 25 3. Electrical device 27, which receive power from self-contained power source 35, moves latch shaft 25 and latch segment 24 that is attached into latch position 4. Latch shaft 25 pulls unlock sleeve segment pin 30 with attached unlock sleeve segment 29 which pulls unlock sleeve fulcrum pin 31 which pulls retrieval arm 32 and forces it to pivot inwards due to retrieval arm anchor pin 33.
5 [0029] Referring to FIG. 5 and 6, the procedure for retrieving the bearing using a running tool will now be described:
1. Unlatched running tool 41 is run in hole via drill pipe 2. Unlatched running tool 41 is landed in profile of unlock sleeve 13 3. Unlock sleeve 13 is moved upwards shearing shear pins 14 10 4. Unlock sleeve 13 continues to travel upwards and contacts latch lock ring pin 16 which is attached to latch lock ring 15 and begins to moves upwards 5. Latch lock ring 15 moves out of lock position and allows latch shaft 25 to move inwards via latch spring 26 6. Unlock sleeve 13 continues to travel upwards and contacts unlock sleeve segment 29 which is attached to unlock sleeve segment pin 30 which pulls lock shaft 25 inwards to ensure latch segment 24 is fully retracted to unlock position.
7. Unlock sleeve 13 continues to travel upwards and contacts unlock sleeve segment 29 which is attached to unlock sleeve segment pin 30 which pushes unlock sleeve fulcrum pin 31 which pushes retrieval arm 32 and forces it to pivot outwards due to retrieval arm anchor pin 33 8. Unlatch lock ring 20 moves into lock position with the aid of unlatch lock ring spring 22 preventing latch shaft 25 from moving.
[0030] Referring to FIG. 11 and 12, an alternative latching assembly 200 is shown. In this example, the latch 202 is carried on a shaft 204 within the housing 205 having a sloped plate 206. The force to move the shaft 204 and therefore the latch 202 is applied to the sloped plate 206. The latching actuator 208 that controls the position of the latch 202 includes an upper portion 210 that engages a top end 212 of the plate 206 and a lower portion 214 that engages a bottom end 216 of the plate 206. As the latching actuator 208 engages the sloped plate 206, the latch 202 is forced out to the latch position as shown in FIG.
11, in which the latch 202 engages the riser assembly (not shown), or back to the release position as shown in FIG. 12, in which the latch 202 is retracted to be flush with the housing 205.
As can be seen, the latching actuator 208 overlaps the sloped plate 206 in an axial direction such that it locks the latch 202 in either the latched position or the released, retracted position. As with the example described above, cantilevered gripping members 218 are provided that are forced inward when the latches 202 move to the release position, such that the gripping members 218 grip the tubular member (not shown) passing through the latching assembly 200. In this example, first end 252 of gripping members 218 has a first pivotal connection 256 between gripping members 218 and actuator 208, as well as a second pivotal connection 258 spaced along gripping members 218 from the first connection 256. This second pivotal connection 258 connects the gripping members 218 to the housing 205. In this example the actuator 208 moves radially in order to move the gripping members 218 between the gripping position and the release position. While the controls are not shown in this example, the latching actuator 208 is preferably a piston that is driven hydraulically.
[0031] At the top of the assembly 200 are a series of bolts 220 that act as a mechanical linkage and are mechanically connected to the latching actuator 208. Should it become necessary, an upward force can be applied to the series of bolts 220 to cause the latching actuator 208 to move upward and force the latches 202 to move to the release position.
During normal operation, the bolts 220 will move up and down with the latching actuator 208, as shown in FIG. 11 and 12, but will not affect the operation of assembly 200.
However, bolts 220 provide a manual release for the assembly 200 in the event that there a failure in the normal operation of the assembly. As depicted, the housing 205 has an upper section 222 with an engagement surface, in this case an inner groove 224, that engages with a release tool (not shown). Once the inner groove 224 is engaged, the release tool may then apply an upward, mechanical force to the upper section 222. As the upper section 222 is lifted, it engages the bolts 220 and lifts them as well. The upward force on the bolts 220 that are connected to the latching actuator 208 provide a second motive force, this one mechanical, to lift the latching actuator 208. As the latching actuator 208 is lifted, it engages the latches 202 and pulls them back to the release position as shown in FIG. 13. As the latches 202 are released, it also causes the cantilevered gripping members 218 to move inward, such that any pipe joints will be gripped by these members, and allow the assembly to be lifted to surface with the tubing string even if the release tool fails. Shear pins or other releasable locks may be provided to ensure that the manual release is not activated unintentionally.
[0032] Referring to FIG. 14 and 15, a further example of a latching assembly 200 is shown. As in FIG. 12 and 13, latches 202 move as a result of latching actuator 208 moving between a first position and a second position. As shown, actuator 208 engages or is attached to latch members 202 and gripping members 218. When actuator 208 moves from the first position to the second position, actuator 208 moves latch members 202 from the latch position shown in FIG. 14 to the release position shown in FIG. 15, where it is flush or recessed with housing 205. At the same time, actuator 208 moves gripping members 218 from the retracted position shown in FIG. 14 to the gripping position shown in FIG. 15 wherein the second end 254 of the gripping members extend into the inner bore such that they can engage a tubular member, similar to what is shown in FIG. 6. Housing 205 is a tubular housing having an outer surface and an inner surface that defines an inner bore, and latch members 202 are carried by the housing. The housing 205 is shaped such that in the latch position latch members 202 extend out from the outer surface, and in the release position latch members 202 are flush with the surface of housing 205, or are recessed into housing 205, as previously discussed.
Gripping members 218 are also attached to the housing 205. In the example shown in FIG. 14 and 15, the gripping members 218 are attached by a pivot point 256 at first end 252. First end 252 also has and a cam surface 250 that engages the actuator 208. In this example, when actuator 208 moves axially along the housing 205 and applies a force to the cam surface 250, the gripping members 218 are rotated by the cam surface 250, pivoting between the gripping position and the release position. FIG. 14 shows the gripping members 218 in a release position. As actuator 208 engages latch 202, cam surface 250 is also engaged such that gripping members 218 move to the gripping position shown in FIG. 15. It will be understood that gripping members 218 may also be rotated using other design, such as those described previously. As shown in FIG. 14 and 15, latching assembly 200 has six gripping members 218. It will be understood that latching assembly 200 may have different numbers of gripping members with different shapes and configurations, as required for the application.

[0033] In the example in FIG. 14 and 15, latches 202 are not connected directly with gripping members 218 as shown in the previous examples. In this case, when actuator 208 engages latches 202 to move them between positions, bolts 220 are also engaged. As shown in FIG. 14, when the latch 202 is in the latching position, bolts 202 are lowered, and upper portion 210 of actuator 208 resides lower than top end 212 of sloped plate 206. As the latch 202 is moved toward the retracted position through the engagement of lower portion 214 of the actuator 208 with the bottom end 216 of sloped plate 206, the top end 212 of sloped plate 206 engages with upper portion 210 of actuator 208. As these sloped surfaces move further into contact, bolts 220 are moved upwards and engage cam surface 250 of gripping members 218. The axial movement of bolts 220 causes the rotational movement of gripping members 218 to the gripping position shown in FIG. 15. As previously described, bolts can also 220 provide for a manual release mechanism in the event of a failure.
[0034] In this patent document, the word "comprising" is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.
[0035] The following claims are to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, and what can be obviously substituted.
The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

Claims (10)

What is Claimed is:

1. A latching assembly, comprising:
a tubular housing having an outer surface and an inner surface that defines an inner bore;
latch members carried by the housing that have a latch position that extends out from the outer surface and a release position that is retracted from the latch position;
a plurality of gripping members pivotally attached to the housing, the gripping members having a first end that is pivotally attached to the tubular housing and a second end extending outward from the first end, the gripping members pivotally moving between a gripping position wherein the second end of the gripping members extend into the inner bore to engage a tubular member and a retracted position; and an actuator that engages the latch members and the gripping members and moves between a first position and a second position, the actuator engaging the latch members and the gripping members such that the actuator moves the latch members from the latch position to the release position and the gripping members from the retracted position to the gripping position as the actuator moves from the first position to the second position.

2. The latching assembly of claim 1, wherein the latching assembly further comprises a first locking element that moves between a locked position to secure the latch members in the latch position, and a release position to release the latch members from the latch position.

3. The latching assembly of claim 1 or 2, wherein the actuator is an electrical actuator.

4. The latching assembly of claim 2 or 3, further comprising a second locking mechanism that moves between a locked position to secure the latch members in the release position, and a release position to release the latch members from the release position.

5. The latching assembly of any of claims 1 to 4, wherein the latch members comprises a spring element that biases the latch members toward the release position.

6. The latching assembly of any of claims 1 to 5, further comprising a secondary release element that slides axially along the housing and is connected to the actuator such that, when actuated, the secondary release element moving the actuator from the first position to the second position.

7. The latching assembly of any of claims 1 to 6, wherein the first end of the gripping members comprise a first pivotal connection that connects the gripping members and the actuator and a second pivotal connection spaced along the gripping members from the first pivotal connection, the second pivotal connection that connects the gripping members and the housing and the actuator moving radially such that the actuator moves the gripping members between the gripping position and the release position.

8. The latching assembly of any of claims 1 to 6, wherein the first end of the gripping members comprises a cam surface that engages the actuator, the actuator moving axially along the housing and applying a force to the cam surface to rotate the gripping members between the gripping position and the release position.

9. The latching assembly of any of claims 1 to 8, wherein the actuator comprises a first portion that moves axially along the housing and a second portion that moves radially within the housing, the first portion engaging the second portion by a sloped engagement surface such that the axial movement of the first portion results in the radial movement of the second portion.

10. In combination:
a riser defining a central bore;
a drill string extending through the riser;
a latching assembly as claimed in any of claims 1 to 9 positioned within the central bore of the riser and receiving the drill string within the central bore of the housing of the latching assembly;
a sealing and bearing assembly mounted to the drill string and attached to the latching assembly.