GB2356239A

GB2356239A - Operating a valve

Info

Publication number: GB2356239A
Application number: GB9926802A
Authority: GB
Inventors: Bilderbeek Bernard Herman Van; Craig Francis Bryce Hendrie
Original assignee: Plexus Ocean Systems Ltd
Current assignee: Plexus Ocean Systems Ltd
Priority date: 1999-11-12
Filing date: 1999-11-12
Publication date: 2001-05-16
Anticipated expiration: 2019-11-12
Also published as: GB2356239B; GB9926802D0

Abstract

This invention is concerned with operation of a valve 30 mounted on a tube 18 which itself is mounted slidably within another tube 26. An operating member 52,54 is mounted on the outer tube 26 and is movable between a position 54 in which a mechanical connection is made with the valve and a position 52 in which the connection is disengaged to allow axial movement of the inner tube 18 within the outer tube 26. The valve may be used at a wellhead. The valve member 22,24 is preferably spherical. The operating member 52,54 may comprise a bushing 56 mounted in the outer tube 26, and a shaft 58 which may be biassed into a position in which it engages the valve member or latched in the disengaged position.

Description

2356239 Operating a Valve This invention relates to an arrangement for

operating a valve, where the valve is positioned in an internal passage in a piece of equipment, and has to be operated f rom outside. One example of such equipment is to be found in oil drilling equipment, and in particular in wellheads, where one tube is located within another and the two tubes need to be axially movable to one another.

The ability to manipulate the valves from outside the outer tubing section makes it possible to close off or open the flow cross section of the inner tube without the need to use separate plugs which have to be placed or removed down the well.

According to the invention, there is provided apparatus for operating a valve in a first tubing section which is positioned within a second tubing section, wherein the valve is movable to control the flow cross section through the first tubing section, and a valve operating member is supported in a wall of the second tubing section and is engageable with and disengageable from the valve to connect or disconnect the valve and the operating member and wherein when the operating member is disengaged from the valve, the first tubing section is able to move axially along the second tubing section without being obstructed by the operating member.

It is important that the valve operating member should not interfere with relative movement between the first and second tubing sections, as it is necessary that these two sections be capable of such movement.

Preferably the operating member is movable radially in and out relative to the wall of the second tubing section between the positions in which it engages with and disengages from the valve.

The valve can be of a type which is operated by a rotary movement about an axis at right angles to the axis of the first tubing section. Thus the valve can be a plug valve or a gate valve but in a preferred form the valve is a so- called ball valve which has a spherical valve body with a bore of diameter substantially equal to the internal diameter of the first tubing section and extending along a diameter of the body. The first tubing section can then have a part-spherical seat for the body and the body and the seat can be arranged so that when the axis of the bore is in line with the axis of the first tubing section, the valve presents substantially no obstruction to the cross section through the first tubing section, and when the axis is at 90' to the axis of the first tubing section, the cross section of the first tubing section is substantially closed.

A valve of this type presents no obstruction to the internal cross section of the first tubing section when the valve is open and whether the valve is open or closed, only projects beyond the external cross-section of the first tubing section at the operating position, if at all.

The operating member itself can be a shaft which extends through a bushing mounted in the wall of the second tubing section, with the shaft being able to move in and out between a first position where it engages with the__751-ve and a second position in which it does not projedt'- beyo'nd the internal wall surf ace of the second tubing section. Thus the operating member is either in a position in which it can operate the valve, or is in a position in which it does not interfere at all with the ability of the first and second tubing sections to move relative to one another.

The shaft preferably has a non-round inner end which can engage with a correspondingly shaped recess in a surface of the valve body so that when the valve and the operating member are engaged, rotation of the shaft about its axis produces corresponding rotation of the valve. Rotation of the shaft about its axis may be limited to correspond with the required rotation of the valve, e.g., 900. The shaft may have an outer end which receives a handle or some other formation to assist in rotating or turning the shaft to operate the valve.

A spring mechanism may bias the operating member into one or other of its end positions, and some means may be provided to hold the operating member, against the spring force in the other end position.

In a second aspect of the invention, there is provided a wellhead in which a first tubing section is positioned within a second tubing section, the wellhead including a valve in the first tubing section, the valve being movable to control the flow cross section through the first tubing section, and a valve operating member supported in a wall of the second tubing section and engageable with and disengageable from the valve to connect or disconnect the valve on the operating member, wherein the first tubing section is able to move axially along the second tubing section when the operating member is disengaged from the valve, without being obstructed by the operating member.

Typically the first tubing section may be a tubing hanger 5 and the second tubing section may be a drilling riser.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a cross section through a wellhead in accordance with the invention; and Figure 2 is an enlarged view of the upper part of the wellhead of Figure 1, showing a valve operating arrangement in accordance with the invention.

Figure 1 shows a wellhead 10 mounted at the top of a well, above a surface casing 12 which extends into the ground.

The wellhead carries a standard production valve cluster 14, and oil or gas produced from the well rises up a production casing 16, into a tubing hanger 18 and through a side outlet 20 to the production valves 14.

At the top of the tubing hanger 18 there are two ball valves 22, 24 which close off the hanger 18, the hanger being a continuation of the bore of the production casing 16. The top part of the tubing hanger 18 with the valves 22 and 24 is surrounded by a drilling riser 26. The ball valves 22 and 24 will normally be closed whilst production is taking place, but can be open to relieve excessive pressure or to pass a tool into the well.

Figure 2 shows the valves on a larger scale. Each valve 22, 24 comprises a valve body 28 which has a spherical outer surface and a bore 30 through the centre. In Figure 2. the upper valve 22 is shown in the open position whilst the lower valve 24 is shown in the closed position. Two valves 22 and 24 are positioned in series as shown with one acting as backup of the other. The valves are mounted in valve seats 32 and 34. The lower seat 32, for the valve 24, itself provides a seat for the valve seat 34 of the upper valve. These seats 32 and 34 are screwed into the tubing hanger on threads 36, 38. Each seat 32, 34 has a part spherical recess in which the valve bodies 28 are located, with conventional seals at 40. These seals will each be annular rings. The reference numeral 42 is used throughout Figure 2 to indicate seals, some of which are seals between the valve seats and the tubing hanger 18.

Each valve body 30 has at one point on its surface a radially extending boss 44 which is received in a corresponding bore in the wall of the tubing hanger, at 46. Seals 42 also prevent leakage past these bosses 44 to the annular space 49 between the tubing hanger 18 and the drilling riser 26. A bearing 48 allows the boss 44 to be rotated about an axis indicated at 50, and rotation of the boss also rotates the valve body 30 between the open and closed positions shown respectively by valves 22 and 24.

Valve manipulators are shown at 52 (for the valve 22) and at 54 (for the valve 24). The manipulator 52 is shown disengaged from the boss 44, whilst the manipulator 54 is shown engaged. The drawing shows one manipulator disengaged and the other engaged for the purposes of explanation. However it is to be expected that either both would be engaged at the same time or both would be disengaged at the same time in the normal course of operation.

Each manipulator 52, 54 comprises a bushing 56 and a shaft 58. The shaft 58 can move axially through the bushing (there are seals 42 positioned between the shaft and the drilling riser 26) so that the inner end of the shaft 58 can engage in a corresponding recess or socket in the 10 adjacent boss 44. The inner end of the shaft 58 will be shaped, as will the socket 60 so that when the shaft 58 is rotated, the boss 44 and the corresponding body 30 will also be rotated. The outer end of the shaft 58 can have a squared head or the likes so that a handle could be fitted 15 on it to assist in rotating the shaft. The shafts 58 can be extended to the position shown at manipulator 54 by means of a thread, by means of a cam or by manual force. 20 The shafts 58 can be biased, e.g. spring loaded with the spring loading either biasing them to the engaged position or biasing them to the disengaged position. It is most likely that they will be biased to the disengaged 25 position, and that the biasing force will have to be overcome to move the shafts to the engaged position. There may be a latch which holds the shaft in the position to which it has been moved against the biasing force so 30 that the shaft is held in its operating position while operation is carried out. The latch can then be released to allow the shaft to be returned by the biasing force to its normal position.

The inner end of the shaft 58 can be resiliently mounted so that it can yield when it is pressed against the boss 44, but can spring into engagement when the correct angular orientation which allows the end of the shaft 58 to enter the socket 60 has been reached.

The actions for extending the manipulator and actuating the valve could be achieved separately or could be mechanically combined by means of threads and cams so that a single external action serves to extend the shaft and rotate the valve body.

Suitable limiting features may be provided to limit the extent of rotational movement of the operating members to that required to operate the valves. Furthermore indicator markings may be provided to indicate from outside the riser 26 the degree of opening of the valves 22, 24.

In order to ensure correct angular and axial alignment between the manipulators 52, 54 and the ball valves 22, 24 when the drilling riser is positioned over thetubing hanger, registration marks may be provided on the wellhead 10 and on the riser to ensure the correct angular orientation. The correct axial orientation will be achieved through the correct positioning of the manipulators relative to the step 62 on the riser 26 which determines the relative axial positions of the riser and of the wellhead (and thus also of the tubing hanger 18).

8 Many different types of valves could be operated using the same principle. The invention is thus not limited to the ball valves shown.

When the manipulator shafts 58 are withdrawn, the drilling riser can be easily removed from the wellhead, and the valves can then be operated directly. Alternatively, if the tubing hanger is to be moved within the riser, this can also be done once the manipulator shafts have been 10 retracted, without any interference from those shafts.

Claims

Claims

Apparatus for operating a valve in a f irst tubing section which is positioned within a second tubing section, wherein the valve is movable to control the flow cross-section through the first tubing section, and a valve operating member is supported in a wall of the second tubing section and is engageable with and disengageable from the valve to connect or disconnect the valve and the operating member, and wherein when the operating member is disengaged from the valve, the first tubing section is able to move axially along the second tubing section without being obstructed by the operating member.
2. An arrangement as claimed in Claim 1, wherein the operating member is movable radially in and out relative to the wall of the second tubing section between the positions in which it engages with and disengages from the valve.
3. An arrangement as claimed in Claim 1 or Claim 2, wherein the valve is operated by a rotary movement about an axis at right angles to the axis of the first tubing section.
4. An arrangement as claimed in Claim 3, wherein the valve is moved between its fully open and fully closed positions by a movement through 90.
5. An arrangement as claimed in Claim 4, wherein the valve comprises a spherical valve body with a bore of diameter substantially equal to the internal diameter of the first tubing section extending along a diameter of the body, the first tubing section having a part spherical seat for the body and the body and the seat being arranged so that when the axis of the bore is in line with the axis of the first tubing section, the valve presents substantially no obstruction to the cross-section through the first tubing section, and when the axis is at 90' to the axis of the first tubing section, the cross-section of the first tubing section is substantially closed.
6. An arrangement as claimed in any preceding claim, wherein the operating member comprises a bushing which is mounted in and sealed with respect to the wall of the second tubing section and a shaft which is sealed relative to the bushing and can move in the bushing between a f irst position where it engages with the valve and a second position in which it does not project beyond the internal wall surface of the second tubing section.
7. An arrangement as claimed in Claim 6, wherein the shaft has a nonround inner end adapted to engage with a correspondingly shaped recess in the valve, so that when the valve and. the operating member are engaged, rotation of the shaft about its axis produces corresponding rotation of the valve.
8. An arrangement as claimed in Claim 6 or Claim 7, wherein the shaft is adapted to receive, at its outer end, a handle or the like to assist in rotating the shaft about its own axis.
9. An arrangement as claimed in any one of Claims 6 to 8, wherein the shaft is spring-biased towards the position in which it is engaged with the valve, and means are provided for retaining the shaft in its disengaged position, against the biasing force.
10. An arrangement for operating a valve substantially as herein described with reference to the accompanying drawing.
11. A wellhead in which a first tubing section is positioned within a second tubing section, the wellhead including a valve in the first tubing section, the valve being movable to control the flow cross-section through the first tubing section, and a valve operating member supported in a wall of the second tubing section and engageable with and disengageable from the valve to connect or disconnect the valve and the operating member, wherein the first tubing section is able to move axially along the second tubing section when the operating member is disengaged from the valve without being obstructed by the operating member.
12. A wellhead substantially as herein described with reference to the accompanying drawing.