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VALVE ASSEMBLY

20200080397 ยท 2020-03-12

    Inventors

    Cpc classification

    International classification

    Abstract

    A valve assembly for an oil, gas or water well, the valve assembly comprising a conduit having a bore; a valve closure member movable on a rotational path around a pivot axis to open and close the bore; a drive member movable on a linear path; and a drive train transmitting force between the drive member and the valve closure member; wherein the drive train comprises a plurality of bearing devices (e.g. ball bearings) constrained in a bearing track. Moving the drive member rotates the valve closure member (e.g. a ball valve) between open and closed configurations to open and close a fluid flowpath in the well. The actuating assembly can be actuated between different configurations using differential fluid pressure, optionally transmitted in an annulus of the well.

    Claims

    1. A valve assembly for a selected one of (a) an oil well, (b) a gas well, or (c) a water well, the valve assembly comprising: a conduit having a bore; a valve closure member movable on a rotational path around a pivot axis so as to open and close the bore; a drive member movable on a linear path; a drive train transmitting force between the drive member and the valve closure member; wherein the drive train includes a plurality of bearing devices, wherein each bearing device is constrained in a bearing track.

    2. (canceled)

    3. The valve assembly of claim 1, wherein at least one of the drive member and the valve closure member is biased resiliently towards the drive train, compressing the drive train between the drive member and the valve closure member.

    4. The valve assembly of claim 1, wherein the bearing devices include ball bearings.

    5. The valve assembly of claim 1, wherein the valve assembly is a subsea valve assembly deployed in a well selected from the group consisting of: (a) an oil well, (b) a gas well, and (c) a water well.

    6. The valve assembly of claim 1, wherein the valve closure member includes a ball valve adapted to rotate to open and close a flowpath in the well.

    7. (canceled)

    8. The valve assembly of claim 1, wherein the bore of the conduit is configured to receive at least one of (a) a string of tools deployed into the well, and (b) wireline deployed into the well.

    9. The valve assembly of claim 1, wherein the valve closure member includes a shoulder member movable pivotally around the pivot axis of the valve closure member.

    10. The valve assembly of claim 9, wherein the shoulder member includes a shoulder engaged by a selected one of the bearing devices in the drive train so as to transmit force between the selected bearing device and the shoulder, and wherein the shoulder member is connected to the valve closure member, wherein pivoting of the shoulder member around the pivot axis of the valve closure member rotates the valve closure member between open and closed configurations.

    11. The valve assembly of claim 1, wherein the shoulder member extends from a flat surface of the valve closure member.

    12. The valve assembly of claim 1, wherein first and second drive members drive the valve closure member in opposite rotational directions.

    13. The valve assembly of claim 12, wherein the first and second drive members respectively rotate the valve closure member between corresponding open and closed configurations, wherein the conduit with the bore is in fluid communication with a fluid pathway through the valve closure member so as to (1) allow fluid passage through the valve closure member in an open configuration, and (2) resist fluid passage through the valve closure member in a closed configuration.

    14. The valve assembly of claim 1, wherein the valve assembly further includes a clutch mechanism, the clutch mechanism disposed to shift between different clutch configurations so as to (1) move the drive member on its linear path, and (2) move the valve closure member.

    15. The valve assembly of claim 14, wherein the clutch mechanism is disposed to shift between different clutch configurations without triggering a corresponding change in configuration of the valve closure member.

    16. The valve assembly of claim 1, wherein the valve assembly is actuated between open and closed configurations by exposure to pressure changes.

    17. The valve assembly of claim 1, wherein the valve assembly further includes: at least one fluid chamber adapted for holding a pressure; and a piston sealed within each fluid chamber; wherein, for each fluid chamber, the valve assembly is disposed to be actuated between different configurations by a fluid pressure differential across the corresponding piston.

    18. The valve assembly of claim 17, wherein the at least one fluid chamber includes first and second fluid chambers each having a corresponding piston, wherein said first chamber is pre-charged with pressurized fluid to a first pressure, and wherein said second chamber is pre-charged with pressurized fluid to a second pressure lower than the first pressure, and wherein the first pressure is a minimum threshold pressure for actuating the valve assembly between different configurations.

    19. The valve assembly of claim 17, wherein at least one piston is exposed to an outer surface of the valve assembly.

    20. The valve assembly of claim 1, wherein the valve assembly further includes a housing having a side wall, wherein the drive member and drive train are disposed in the side wall so as to be isolated from the bore of the valve assembly.

    21. The valve assembly of claim 1, wherein the valve assembly further includes a locking mechanism, the locking mechanism disposed to lock the valve assembly against changes in configuration.

    22. (canceled)

    23. (canceled)

    24. (canceled)

    25. (canceled)

    26. (canceled)

    27. (canceled)

    28. (canceled)

    29. (canceled)

    30. (canceled)

    31. A ball valve for opening or closing a bore in a fluid pathway in a selected one of (a) an oil well, (b) a gas well, or (c) a water well, the ball valve comprising: a drive member movable on a linear path; a valve closure member movable on a rotational path around a pivot axis; a drive train transmitting force between the drive member and the valve closure member; wherein the drive train includes a plurality of bearing devices, wherein each bearing device is constrained in a bearing track.

    32. An actuator assembly for actuating a mechanism in a selected one of (a) an oil well, (b) a gas well, or (c) a water well, the actuator comprising: a drive member movable on a linear path; a rotary member movable on a rotational path around a pivot axis; a drive train transmitting force between the drive member and the rotary member; wherein the drive train includes a plurality of bearing devices, wherein each bearing device is constrained in a bearing track.

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    [0059] In the accompanying drawings:

    [0060] FIGS. 1 a-e show plan, sectional, detailed section of a ball valve, and perspective views of a valve assembly for an oil, gas or water well when running into a hole;

    [0061] FIGS. 2 a-c show views similar to FIG. 1 of the valve assembly with an interlock released;

    [0062] FIGS. 3 a and b show views similar to FIG. 1 a and b of the valve assembly with an actuator piston moving down while the valve remains open;

    [0063] FIGS. 4 a-d show views similar to FIG. 1 of the valve assembly with the actuator piston moving upwards in a further cycle in which the upward movement actuates the drive train and shifts the valve from open to closed;

    [0064] FIGS. 5 a-d show views similar to FIG. 1 of the valve assembly with the actuator piston moving down in a further cycle while the valve remains closed;

    [0065] FIGS. 6 a-e show views similar to FIG. 1 a-e of the valve assembly with the actuator piston moving upwards in a further cycle in which the upward movement actuates the drive train and shifts the valve from closed to open;

    [0066] FIG. 7 shows a perspective view of the valve assembly in the FIG. 1 configuration;

    [0067] FIG. 8 shows a perspective view of the valve assembly in the FIG. 4 configuration; and

    [0068] FIG. 9 shows a perspective view of the valve assembly in the FIG. 6 configuration.

    DETAILED DESCRIPTION OF EXAMPLES OF THE INVENTION

    [0069] Referring now to the drawings, a valve assembly 1 has a body 10 with a bore 10b, the body 10 comprising an upper sub 12 connected to a lower mandrel 11. The top sub 12 is attached by screw threads to a ball valve housing 30h, which houses a valve closure member in the form of ball valve 30, having a ball 31 movable on a rotational path around a pivot axis 30x to open and close the bore 10b. The ball 31 is partially spherical, having flats 31f on opposing sides (best seen in FIGS. 7-9) and having a central flow path extending through the ball 31, which can rotate in and out of register with the central bore 10b around a ball axis 30x to open and close the bore 10b. The flats 31f on the opposing sides are disposed on either side of the central flow path through the ball 31 and the axis 30x of the ball passes through the flats. The internal diameter of the bore through the ball 31 is substantially the same as the internal diameter of the bore 10b at its maximum, as can be seen in FIG. 1, so the ball 31 does not reduce the available internal diameter of the valve assembly when open. The bore 10b in this example comprises a fluid conduit, providing a flowpath for fluid through the valve assembly 1, which in this case is opened and closed by the rotation of the ball 31.

    [0070] The lower end of the valve housing 30h has an internally threaded bore which receives the upper end of the mandrel 11, which has a co-operating external thread. The mandrel 11 is connected to the valve housing 30h at the beginning of the assembly procedure. All the components are assembled onto the mandrel from the bottom end. The ball 31 is supported on the pivot axis 30x within the housing 30h which perpendicularly traverses the central axis 10x of the bore 10b, so that the ball 31 can pivot around the ball axis 30x within the bore 10b.

    [0071] The valve assembly 1 also has a drive member in the form of pistons 21a, 21b, movable on a linear path and housed in side-by-side cylinders in the wall of the housing (as best seen in FIG. 7-9), and a drive train 20 transmitting force between the pistons 21 and the ball 31, in order to drive rotation of the ball 31 via the linear movement of the pistons 21. The drive train 20 comprises a plurality of bearing devices 25 constrained in a bearing track 26, which can optionally comprise a tubular recess within the housing 30h forming a bore that receives the upper ends of the pistons 21 and the bearings 25, and which defines the path on which the bearings move between the pistons 21 and the ball 31.

    [0072] FIGS. 1a-1e and FIG. 7 show the valve assembly 1 in a configuration suitable for running into a well. The ball 31 is in an open configuration for run-in. From left to right as shown in the drawings (in which the lower end of the assembly 1 which is deeper in the hole and closer to the formation is on the left hand side, and the upper end of the assembly which is closer to the surface is on the right) the valve assembly 1 comprises a number of inter-connected sleeve components comprising an actuator 60, an interlock assembly 50, and a clutch 40, axially spaced from the ball valve 30, each surrounding the mandrel 11 and connecting together to move axially as a single sleeve along the exterior surface of the body 10. Optionally a further sleeve or housing can be placed over the valve assembly 1 to protect the components from, for example, debris ingress.

    [0073] The actuator 60 has a housing 62 fixed via a screw-thread to the outer surface of the mandrel 11, with an annular pressure chamber 63 formed in the annulus between the housing 62 and the mandrel 11, and which is sealed to the mandrel 11 at the lower end. The chamber is in fluid communication through its upper end with a narrower circumferential annular recess housing and sealing a lower portion of an actuator piston 61, forming a sleeve around the mandrel 11 and movable axially within the circumferential annular recess up and down the body 10. The chamber 63 and the recess are pre-charged with pressurised fluid, for example nitrogen, at surface before the assembly is run downhole. The pressure of the fluid can be at several thousand psi, for example 1000-3000 psi (approximately 7-21 MPa). In one example, the pressure may be closer to 2000 psi (approximately 14 MPa). The pressure in the chamber 63 is above ambient pressure in the well, and so acts on the sealed portion of the actuator piston 61 retained within the circumferential recess between the interior of the actuator housing 62 and the exterior surface of the mandrel 11, normally urging the actuator piston 61 upwards relative to the chamber 62 in the absence of other forces acting on the actuator piston 61. Hence, at ambient pressure in the well (e.g. in the annulus) and at the surface, the actuating piston 62 is normally extended out of the recess by the pressure within the chamber.

    [0074] The interlock assembly 50 immediately above the actuating piston 61 has an interlock piston housing 52 and an interlock piston 51 and optionally acts to lock the sleeve formed by the actuator piston 61 and the clutch 40 onto the body in a fixed position on the body 10 for running into the hole, and optionally to release the sleeves once actuation of the valve assembly commences. In this example, the interlock piston 51 is partially contained within the interlock piston housing 52. The actuator piston 61 has bayonet-type protrusions on its interior surface that are circumferentially spaced, which align with grooves in the interlock piston 51 so that while initially separate, once assembled, the interlock piston 51 and actuator piston 61 are locked together by a bayonet-style fitting so they move axially as one piece along the body 10. The interlock housing 52 is keyed to the interlock piston 51 by a shear pin 54 that passes through the interlock housing 52 and into the interlock piston 51, holding both components 51, 52, stationary relative to each other when running into a hole. The interlock housing 52 and interlock piston 51 define a sealed pressurised interlock chamber 56 between them. The pressurised interlock chamber 56 is pre-charged at the surface with fluid, for example a compressible fluid like a gas such as nitrogen, but is normally pressurised to a lower value than the chamber 63; for example, 1 atm (101 kPa) may be sufficient. The pressurising of the interlock chamber 56 can prevent premature release of the interlock. The details of the interlock can be changed in various different examples.

    [0075] When running into the hole, the actuator piston 61 and interlock piston 51 are keyed into the mandrel 11 by a snap ring 53, held in a groove on the outer surface of the mandrel 11 to maintain the axial positions of the various components of the interlock assembly 50, the clutch 40 and the actuator piston 61 relative to the mandrel 11 when running into the hole.

    [0076] In the example shown in FIG. 1, the clutch 40 has two pin sleeves 43, 42 disposed above the interlock assembly 50. Sleeve 43 is connected to the upper end of the interlock piston by a screw thread. Sleeve 43 houses an anti-rotation pin 47 keyed into an axial slot in the mandrel 11, so that the sleeve 43 is constrained to only move axially along the mandrel 11 and does not rotate relative to the mandrel 11. Sleeve 42 is connected to sleeve 43 by a bearing race 45 and can rotate relative to sleeve 43 and the other sleeves above it but still moves axially with the sleeve 43. Sleeve 42 houses a J-pin 44 in engagement with a J-slot, and axial movement of the sleeves 43, 42 drives movement of J-pin 44 in the J-slot, rotating sleeve 42 around the body 10 relative to the non-rotating sleeve 43 and the mandrel 11. At the upper end of the clutch 40, facing the ball valve housing 30h, there is a clutch ring 41 which is fixedly attached at a first (lower) end to the rotating sleeve 42, for example by grub screws or by a screw thread, and therefore rotates with rotating sleeve 42 around the mandrel 11 under the control of the J-slot arrangement between the rotating sleeve 42 and the mandrel 11, relative to the upper sleeves 43, 50, 61.

    [0077] The second (upper) end of the clutch ring 41 facing the ball valve housing 30h is crenelated, with platforms 41p and slots 41s. The platforms 41p and slots 41s can all be of equal dimensions, or alternatively some may be wider than others. In this example, for example FIG. 1d, it can be seen that there is at least one wider slot 41ws and at least one wider platform 41wp. The crenelations engage with the pistons 21 forming part of the drive train 20. As the clutch ring 41 rotates, the platforms and slots may be presented in different configurations to the pistons 21 as will be described in more detail below.

    [0078] FIGS. 2a-2c show the valve assembly 1 after having been run in to the well, and with the interlock uncoupled, so that the assembly is ready for actuation. Notice that the components of the clutch 40, namely the fixed and rotating sleeves 43, 42 are in the same relative positions as in FIG. 1 when the assembly 1 is run into the hole, the upper end of the clutch ring 41 is still engaged with the pistons 21, the bayonet connection between the interlock piston 51 and the actuator piston 61 is still engaged, and the only change is in the position of components of the interlock assembly 50 (the interlock housing 52 has moved up slightly to expose the snap ring 53).

    [0079] Prior to reaching the FIG. 2 configuration, the valve assembly 1 in this example is run into the well below the tubing hanger and above a production packer, and is disposed in the annulus between the production tubing and the casing or other outer wall of the well. Before the assembly can be used in this position, the interlock assembly 50 needs to be uncoupled to allow movement of the actuator piston 61, the interlock assembly 50 and the clutch 40 axially along the body 10. To do this, once the valve assembly 1 is in place between the tubing hanger and the production packer, the production packer will be set and tested from annulus above to a pressure that will release the interlock assembly thus starting the closure of the ball valve. For example, the wellbore annulus housing the valve assembly 1 is pressured up from surface through the well's annulus port to several thousand psi, for example 3000-6000 psi (21-41 MPa) or to another pressure higher than the pressure in the chamber 63. The high annular pressure outside the assembly 1 applies a pressure differential to the interlock housing 52, which is urged upwards relative to the interlock piston 51 by the pressure differential across the interlock housing 52 because the annulus pressure is much higher than the atmospheric pressure trapped in the chamber 56, consequently applying a shear force to the shear pin 54 connecting the piston 61 to the interlock housing 52. At a threshold annulus pressure, the shear pin 54 shears and the fluid in the chamber 56 collapses as the interlock piston housing 52 moves up the mandrel 11 relative to the interlock piston 51 to the FIG. 2 position. FIG. 2c shows the interlock piston housing 52 having moved upwards over the interlock piston 51. As it moves up the body 10 relative to the actuator piston 61 and interlock sleeve 51, the interlock housing 52 uncovers the snap ring 53 and releases it to spring radially outwards from the groove in the mandrel 11. Release of the snap ring 53 from the groove in the mandrel 11 frees the inter-connected assembly of the interlock piston 51 and the actuator piston 61 to move axially downwards along the exterior surface of the mandrel 11 as a unit, urged in that direction by the pressure differential acting on the actuation piston 61. The annular pressure is higher than the pressure in the chamber 63, so the actuation piston 61 and attached interlock piston 51 together move down under the pressure differential across the piston 61 as the lower end of the piston 61 slides down into the circumferential recess 63 to the FIG. 3 position. The axial travel of the interlock assembly 50 and the clutch 40 is limited in the downhole direction by a stop ring 55 fixed to the outer surface of the mandrel 11 which abuts a downwardly facing inner shoulder 43s on the axial pin sleeve 43 at the greatest extent of downhole travel (see FIG. 3). The uphole movement of the sleeves 61, 50, 40 is limited by an external annular no-go shoulder 11n on the outer surface of the mandrel (best seen in FIG. 3) which abuts an internal annular no-go shoulder 41n on the inner surface of the clutch ring 41 and prevents the clutch ring from further upward axial movement from the FIG. 2 position. The interlock piston 51 and the actuator piston 61 remain inter-engaged with each other, and sections 40, 50, and actuator piston 61 move axially together as a unit to actuate the ball valve 30. This limitation of upward movement protects the pistons 21 from excessive axial force applied by the force acting on the actuating piston 61, and protects the j-pins from being over-loaded at the end of the J-slot.

    [0080] In response to changes in the pressure differential between the chamber 62 and the annulus outside the bore 10b, the clutch 40, interlock assembly 50, and actuator piston 61 thus move together axially relative to the mandrel 11 of the valve assembly 1. Pressure differentials can be applied from the surface via a conventional annulus port in the well to cycle the assembly 1 between different configurations, and optionally through a sequence of configurations leading to opening and closing of the ball valve 30, without other transmission of power or signals by other methods into the well. In some examples, the valve can be cycled through different configurations by resilient devices such as springs or electrical actuators etc., and actuation by pressure differentials is not essential. Optionally when the pressure in the annulus is below the pressure in the chamber 62, the piston 61 extends and drives the clutch 40 into contact with the components of the ball valve 30, which maintains the configuration of the ball valve 30 even when the annulus bore is de-pressurised. Since the configuration of the ball valve 30 depends on the configuration of the clutch 40 in different rotational positions, the annulus pressure can be cycled several times (depending on the configuration of the clutch/ball valve interface) without necessarily changing the configuration of the ball valve 30.

    [0081] FIGS. 3a and 3b show the sleeve components 61, 50, 40 of the valve assembly 1 after moving downwards along the body 10 towards the actuator end of the valve assembly under the force of the pressure differential acting on the actuator piston 61. Actuator piston 61 slides deeper into the circumferential recess connected to the actuator housing 62 in response to the pressure differentials applied by the high annulus pressure. Anti-rotation pin 47 tracks along the axial slot and maintains the rotational alignment of the axial pin sleeve 43, the interlock assembly 50, and the actuator 60 with respect to the mandrel 11. Rotation of the actuator piston 61 relative to the mandrel 11 is undesirable in this example due to the interlocking engagement of the circumferentially discontinuous bayonet protrusions connecting the actuator piston 61 to the interlock piston 51.

    [0082] Axial downward movement of the clutch 40 causes the J-pin 44 to track in the J-slot and rotates the rotating sleeve 42 in accordance with the geometry of the J-slot, which also rotates the clutch ring 41 fixedly attached to the lower end of the rotating sleeve 42 via a screw thread. As the sleeve components 61, 50, 40 have moved down towards the actuator end of the valve assembly, the clutch ring 41 is retracted away from the drive train 20 and pistons 21 during rotation. Notice the different relative positions of the J-pin 44 in FIGS. 2 and 3, illustrating the rotation of the clutch ring 41 and J-pin housing relative to the axial pin sleeve 43. The assembly can retain this position for as long as the annular pressure is applied to overcome the pressure in the chamber 63. Thus pressure signals to control the configuration of the valve assembly can be transmitted in the annulus of the well, without taking bore pressure into consideration, allowing more flexibility of operation in certain examples of the valve assembly.

    [0083] Venting or other reduction in the annular pressure triggers movement from the FIG. 3 position.

    [0084] Starting from the FIG. 3 position, as annular pressure falls below the pressure in the chamber 63, the actuating piston 61 is driven upwards by the expansion of the gas in the chamber 63. The upper sleeve components 61, 50 and 43 remain circumferentially fixed by the J-pin 47 in the axial slot as before, and the clutch ring 41 rotates anticlockwise again under the control of the J-slot and the J-pin 44 on the rotating sleeve 42 as the sleeve components 61, 50, 40 together move axially upwards towards the valve housing 30h and the pistons 21. One single axial translation of the clutch ring 41 in this example up or down through the J-slot rotates the clutch ring 41 in an anticlockwise direction 45 from the previous position. In this example, the circumferential spacing between adjacent axial portions of the J-slot is regular, but in other examples, this can be varied if desired. Two pistons are provided in this example, 21a and 21b, which together act to drive the movement of the ball valve 30 in different rotational directions, although it would be possible to provide a modified example with a single piston 21 adapted to drive the ball valve in a single direction. Pistons 21a and 21b are arranged within cylinders disposed side by side at the same axial position on the ball valve housing 30h with a circumferential spacing between them so that the pistons 21a, 21b align axially with different circumferentially spaced parts of the crenelated end of the clutch ring 41. The cylinders are sealed within the body outside the bore 10b. For a given configuration of the valve assembly 1, prior to axial movement of the clutch ring 41 towards the actuator, a platform 41p of the clutch ring 41 may be in engagement with, for example, piston 21a. At the same time, piston 21b may be within a slot 41s, as best seen in FIG. 1c, so that the pistons 21a, b are in opposite configurations.

    [0085] The sleeves in the interlock 50 and clutch 40 retract along the mandrel 11 under the influence of annular pressure changes, and return to their original axial position, with the clutch ring 41 having rotated 45 as described above. In this example, several axial cycles of the clutch 40 may take place before any change in the configuration of the drive train 20 is initiated, that is, the clutch ring 41 may translate axially up and down the body 10 several times and upon returning each time, may again present a platform 41p (e.g. a different platform 41p) to piston 21a, and may again present a slot 41s to piston 21b. In this event, the configuration of the ball valve 30 does not change, as the pistons 21 do not encounter any change in the geometry of the clutch ring 41 and so do not move in response. In this example, several cycles of axial movement of the sleeves 61, 50, 40 with corresponding rotation of the clutch ring 41 have occurred between the FIG. 3 and FIG. 4 positions, as can be seen by comparing the relative positions of the J-pin 44 in FIGS. 4 and 2. This is useful, as it allows an operator to run through a sequence of pressure changes (to pressure test the well and/or activate other tools in the well etc.) before finally triggering a functional change in the valve assembly 1. This also reduces the risk of an inadvertent triggering of a functional change by a one-off kick in the pressure profile of the well, and allows pressure checking regimes to be part of the triggering sequence. The number and effects of pressure changes in the triggering sequence can be changed simply by modifying the number of lateral deviations in the J-slot, or the arrangement of platforms and slots on the end of the clutch ring 41.

    [0086] Notice that for brevity in the drawings, not all of the different positions of the valve assembly in the sequence are shown in the drawings, as some of them are substantially identical to those shown in FIGS. 2 and 3, except that the rotating sleeve 42 has moved around the body 10 with the clutch ring 41, and the pistons 21 engage different but similarly shaped slots and protrusions in the intermediate positions. As the same shapes are presented to the pistons 21 or the ball 31, there is no difference in the effect of these intermediate positions, and the pistons 21 remain in the position shown in FIGS. 1-3 throughout the different intermediate positions of the clutch. As described above, the number of intermediate positions can be varied in different examples.

    [0087] In the final cycle of axial translation of the clutch 40 before a configuration change in the pistons 21, when the clutch ring 41 approaches the ball valve housing 30h when moving into the FIG. 4 position, the crenelated end of the clutch ring presents a different profile of protrusions and slots to the pistons 21 to change their configuration, and this rotates the ball 31 in the valve 30 as will be described below. In this example, the crenelated end of the clutch ring 41 has an irregular profile on its upper end, which eventually rotates around the body 10 to engage the pistons 21 in a different configuration, but in some examples, instead of a differential in the crenelated pattern of the clutch ring 41, the differential can be provided in the J-slot, which can move the clutch ring 41 in different rotational intervals if desired.

    [0088] FIGS. 4a-4d and FIG. 8 show the actuation of the ball 31 to the closed configuration. The clutch ring 41 has rotated and, in this example, presented a wider platform 41wp to the piston 21b. Piston 21b has been pushed upwards into the ball valve housing 30h by the wider platform 41wp and has driven the movement of the bearings 25 around the bearing track 26. In this example, the bearings 25 are ball bearings, but they can be cylindrical or another shape in other examples. Piston 21a is not aligned with a slot and has been pushed downwards as a result of the movement of the bearings 25 and now sits within a slot 41s adjacent to the wider platform 41wp. The pistons 21 are optionally resiliently biased towards the ball 31 and this compresses the drive train 20 between the two pistons 21; this resilient bias may be in the form of a load applied to one end of the pistons 21 by, for example, a resilient spring, or a hydraulic pressure differential.

    [0089] The bearings 25 engage at one end with a respective piston 21a, 21b, and at the other end with a shoulder member which in this example is in the form of a paddle 35 connected to the ball 31. In this case, the two bearing trains from the pistons 21a, 21b engages with separate shoulders on opposite sides of the paddle 35, and act on the shoulders to rotate the paddle 35 in opposite directions. For example, linear movement of a first piston, for example, compression of piston 21b along its linear path axially towards the ball 31 pushes the ball bearings 25 acting on a shoulder on one side of the paddle 35 to drive rotation of the paddle 35 anticlockwise around the pivot axis 30x of the ball 31. The anticlockwise rotation of the paddle 35 pushes the bearing train engaging the shoulder on the other side of the paddle 35 to extend the other piston 21a away from the ball in the opposite linear direction from piston 21b. To rotate the paddle 35 in the opposite direction, piston 21a is compressed towards the ball 31, and piston 21b is extended away from it. The paddle 35 is directly connected to the ball 31, and so rotation of the shoulders on the paddle 35 rotates the ball 31 along its rotational path.

    [0090] The paddle 35 is fixed to the ball 31 on one of the flats 31f located on the sides of the ball on opposite sides of the bore through the ball 31 (see FIGS. 7-9). The paddle 35 extends radially in line with the pivot axis 30x from the flat 31f and moves pivotally with the ball 31 in the same rotational path around the pivot axis 30x of the ball valve 30. The paddle 35 is engaged by the bearings 25 in the drive train 20, and rotation of the paddle 35 rotates the ball 31 between open and closed configurations.

    [0091] The flat 31f is formed in this example by milling or cutting away a portion of a wall of the ball 31. The thickness of the wall of the ball 31 is selected to be thick enough to resist the high forces the cut-away portion(s) will be exposed to, while maintaining as large an internal diameter as possible when the ball valve 30 is in the open configuration.

    [0092] The paddle 35 in the present example has a generally cylindrical central column with extends perpendicular to the axis 10x of the bore from the flat 31f along the axis 30x; and a spur extending from the central column in a radial direction with respect to the axis 30x, away from the pistons 21. The spur has two outer shoulders provided by respective side walls on opposite sides of the spur extending in planes that are parallel to the axis 30x. The planes of the shoulders are not parallel to one another, and diverge from the central column at approximately 45 with respect to one another, as best seen in FIG. 1c. The precise angle between the planes of the shoulders is not important. The shoulders extend radially with respect to the axis 30x from the central column of the paddle 35, and provide shoulders on opposing sides of the paddle 35 for the bearings 25 to press against in order to transmit force from the pistons 21 to the ball 31. The bearings 25 are constrained in the race 26 formed in the housing 30h which winds in an arc around part of the cylindrical central column of the paddle 35, so that the central column forms part of the bearing track retaining the bearings. The paddle 35 has a planar cap covering the central column and enclosing the bearings 25 which engage the shoulders of the spur underneath the cap. The cap assists with retaining the bearings 25 within the bearing track as they move. The cap can have a thin profile in order to keep the extent of radial protrusion of the paddle 35 in the direction of the axis 30x to a minimum.

    [0093] As a first piston, for example 21b, is pushed upwards towards the ball valve 30 (as shown in FIGS. 4a-4d), the bearings 25 are in turn pushed around the arc of the bearing track 26 against the spur, which drives the rotation of the spur and central column in an anticlockwise direction. This pushes the opposite shoulder on the other side of the spur against the bearings between the opposite shoulder and the second piston 21a, causing the second piston 21a to move downwards towards the clutch ring 41 under the force applied by the first piston 21b. Since the piston 21a is aligned with a slot 41s and is not prevented from extending, it extends downwards into the slot 41s under the force of the first piston 21b. As the bearings 25 drive the rotation of the paddle 35 connected to the ball 31 at the flat 31f, they drive rotational movement of the ball 31 in the same anticlockwise direction. The movement of the pistons 21 and the engagement of the bearings 25 with the paddle 35 therefore actuate the ball 31 between open and closed configurations.

    [0094] Pressure cycling from 1,500 psi-3,000 psi is sufficient to cycle the assembly to close the ball valve. Differential pressure of 1,000 psi in this example will generate a sufficient load to move the piston drive rod into the ball housing. When the ball is closed and the actuating piston 61 is cycled to final position the annulus pressure may optionally be maintained while then applying tubing pressure above the ball 31 to reduce any differential across the ball 31 to zero which can help to open the valve 30. The final position can optionally provide multiple seals (metal, dual peek and dual elastomer backup are all options) on the piston rods.

    [0095] FIGS. 5a-5d show a later cycle of the valve assembly 1, the actuator piston 61, interlock assembly 50, and clutch 40 having moved again into a retracted configuration where the clutch 40 is axially spaced away from the piston 21. The ball 31 remains in the closed configuration during the rotation as the intervening positions between those shown in FIGS. 4 and 5 have not changed the configuration of the pistons 21, as the same pattern of platforms and slots have been presented to the pistons 21 on each cycle of the assembly. Since the pistons 21 have not moved from the FIG. 4 position, the ball 31 has not rotated. However, notice that the rotating sleeve 42 has moved around the body 10 in the various intermediate positions, and is now approaching the starting position of FIG. 2. Notice that once again for brevity, some of the intermediate positions of the valve assembly in the sequence leading up to FIG. 5 are not shown in the drawings, as some of them are identical to those shown in FIGS. 3 and 4, except that the rotating sleeve 42 has moved around the body 10 with the clutch ring 41, and the pistons 21 have engaged different but similarly shaped slots and protrusions in the intermediate positions.

    [0096] FIGS. 6a-6e and FIG. 9 show the return travel of the actuator piston 61, interlock assembly 50, and clutch 40 following from the configuration shown in FIGS. 5a-5d into the last position in which the ball is rotated to the open position. There is a wider slot 41ws, best seen in FIG. 6c, which has changed the configuration of the crenelations to present a platform 41p to piston 21a and a slot 41s to piston 21b. The load previously applied to piston 21b is transferred to piston 21a, which is pushed axially by the platform 41p towards the ball 31, driving the bearings 25 in the opposite direction to FIGS. 4a-4d. Piston 21b moves towards the clutch ring 41, driven by the bearings 25 moving around the track 26, and extends into the wide slot 41ws. Movement of the bearings 25 around the paddle 35 rotates the ball 31 back into the open configuration as previously described.

    [0097] When reaching the FIG. 6 position, the clutch ring 41 is optionally locked in position in this example. This is achieved by two locking pins (providing a primary and a backup lock) 41l resiliently biased in compression between the inner surface of the clutch ring 41 and the outer surface of the mandrel 11. The outer surface of the mandrel 11 has a pair of stop grooves 11g (one is visible in FIG. 3) extending circumferentially perpendicular to the axis 10x of the bore for a short distance around the outer surface, but initially being circumferentially out of register with the locking pins 41l. When the assembly is in the FIG. 1 position, with the shoulder 11s abutting against the shoulder 41n, and the sleeves 61, 50, 40 at their uppermost limit of axial movement, the locking pins 41l are circumferentially spaced around the body 10, but at the same axial position, just to the anticlockwise side of the grooves 11g. Anticlockwise movement of the pins 41l with the clutch 41 moves the pins 41l around the body away from the groove 11g, and they maintain their resilient bias between the inner surface of the clutch ring 41 and the outer surface of the mandrel 11 until just before the FIG. 6 position, in which the clutch ring 41 has moved around 315 around the body, and the pins 41l approach the start of the grooves 11g. As the clutch ring 41 moves round, the pins 41l reach the grooves 11g and extend resiliently into the grooves 11g, in which they can track for a further short distance, but further rotation of the clutch ring 41 around the body 10 is limited by the circumferential dimensions of the grooves 11g, which the pins 41l cannot escape once they are extended. Hence, the assembly locks in the FIG. 6 open position in this example, with the ball 31 open and must be recovered to the surface before being reset. Note that the J-slot 46 engaged by the J-pin 44 in this example is linear (rather than endless) and the FIG. 6 position coincides with the pin 44 tracking down the final axial track of the J-slot 46.

    [0098] The valve assembly 1 optionally has a secondary contingency shifting mechanism above the ball 31, to change the configuration of the ball 31 if the primary opening mechanism fails. The ball 31 is mounted on pivot axis 30x between lower and upper ball seats 32, 33 fixed within the housing 30h as is best shown in FIG. 6e. Optionally, the ball 31 is urged against one of the seats 32, 33 by resilient device such as a disc or wave spring optionally disposed between the ball 31 and one of the seats 32, 33, which will apply a pre-load between the ball and the other of the seats 32, 33 to enhance low pressure sealing. Each side of the ball 31 has a flat plateau section, on one side bearing the paddle 35, driving rotation of the ball 31 in normal operation, and on the opposite side, bearing a J-shaped cam recess 71r engaging a pin on a lower end of a release rod 71 extending from and connected to a release sleeve 72. The release sleeve 72 is ordinarily locked in place in the upper ball seat 33 by shear pin 73, which when sheared unlocks the release sleeve 72 to move in an axial direction with respect to the upper ball seat 33, pulling the release rod 71 upwards a tracking it through the J-shaped recess 71r on the flat face of the ball 31, causing the ball 31 to rotate around its pivot axis 30x. The release sleeve 72 can be unlocked to move axially upwards in the bore (to the right hand side of the drawings) by shearing the pin 73. Optionally the ball seats are fixed and cannot move axially. In this example, the secondary shifting mechanism includes a fishing neck 77 formed at the uphole end of the release sleeve 72. A fishing tool (not shown) can be deployed downhole into the bore of the assembly 1 to engage the fishing neck 77, which can then be pulled axially upwards under a force applied from the surface to shear the pin 73 and axially move the release sleeve 72 to rotate the ball 31 either from the open configuration to the closed configuration, or vice versa.

    [0099] FIGS. 7-9 show partial cutaway views of the ball valve 30, the clutch ring 41, and the J-pin 44 in J-slot 46. The axial slot 48 contained within sleeve 43 can be partially seen. FIG. 7 shows the ball 31 in the first open configuration, as shown in FIGS. 2a-2c, with the J-pin 44 at the beginning of J-slot 46. FIG. 8 shows the clutch ring 41 having undergone 2 cycles of rotation, equal to 90, to actuate the ball 31 to the closed configuration as shown in FIGS. 4a-4d. FIG. 9 shows the J-pin 44 at the end of the J-slot 46, having actuated the ball 31 back into its open configuration as shown in FIG. 6.