Abstract: A well barrier for sealing a downhole conduit is described. The well barrier comprises a housing defining a throughbore having a longitudinal axis, a valve actuator and a flapper valve. The flapper valve includes a flapper attached to the valve actuator. The flapper valve and the valve actuator are axially movable with respect to the housing in a direction parallel to the longitudinal axis. The flapper is adapted to move from one of a throughbore open and throughbore closed positions to the other of said open and closed positions when the actuator and flapper valve move a predetermined axial distance.

Abstract: A bore selection device for use with a dual bore subsea system is disclosed. The bore selector (18) can be remotely actuated to provide selection between a production bore (12) and an annulus bore (16) without a rotating mechanism or flapper valve. Embodiments of the invention are disclosed. In one embodiment a pair of rams (20) having a ram head (20a, 20b) defining parts of a guide funnel (30a, 30b) are hydraulically actuatable so that when the rams are actuated and closed the guide funnel (30) is formed which couples a part of the production bore (126) to the annulus bore (16a).

Abstract: A well barrier for sealing a downhole conduit is described. The well barrier includes a housing defining a throughbore having a longitudinal axis, a valve actuator and a flapper valve. The flapper valve includes a flapper attached to the valve actuator. The flapper valve and the valve actuator are axially movable with respect to the housing in a direction parallel to the longitudinal axis. The flapper is adapted to move from one of a throughbore open and throughbore closed positions to the other of said open and closed positions when the actuator and flapper valve move a predetermined axial distance.

Abstract: A tensioning apparatus for applying a substantially constant tension to a workover riser (12) includes a first portion (40) adapted to be coupled to a workover riser, a second portion (44) adapted to be coupled to a marine riser (14) and tensioning means (46) for providing relative movement between the first portion and the second portion to, in use, tension the workover riser.

Abstract: An apparatus (10) for remotely running a subsea production tree (12) and desuspending a well is described. The apparatus comprises a tree running tool (16) adapted to be connected to a production tree, at least one downhole tool, at least one of the tools being a plug retrieval tool (22) and a tool deployment device (18) in hydraulic communication with at least the plug retrieval tool to hydraulically operate the plug retrieval tool.

Abstract: A well intervention system is described which has a riser access drive adapted to be located below a vessel, or a rig, work floor. The riser is tensioned and extends from a subsea wellhead to the access device which, in use, is attached to the riser at the location below the work floor. Embodiments of the invention are described.

Abstract: A blow out preventer (10) includes a housing (40) defining a longitudinal throughbore (16) and a ram cavity (34) and at least one pair of opposed rams (12, 14) located in the ram cavity. Each ram includes a seal (18, 24) disposed on an upper surface (20, 26) and the rams are movable transversely across the bore. The blow out preventer further includes at least one seal seat (30) having a seal surface (36) for engaging with the ram seals. There is a seal seat associated with each at least one pair of rams, the seal seat being moveably mounted in the ram cavity. In one embodiment the seal seat continuously engages the rams as the rams move from a cavity open position to a cavity closed position.

Abstract: A tensioning apparatus for applying a substantially constant tension to a workover riser (12) includes a first portion (40) adapted to be coupled to a workover riser, a second portion (44) adapted to be coupled to a marine riser (14) and tensioning means (46) for providing relative movement between the first portion and the second portion to, in use, tension, the workover riser.

Abstract: A wellbore control device for use in a blow out preventer is described. The control device comprising a housing defining a throughbore, a gate, the gate being movable between a throughbore open position and a throughbore closed position, a first stem attached to the gate and a second stem releasably engageable with the gate, the first and second stems being arranged such that a portion of each stem is exposed to an internal housing pressure and a portion of each stem is exposed to an external housing pressure. When the internal pressure is greater than the external pressure, the pressure differential results in a force being applied to the gate to move the gate to, or retain the gate in, the throughbore closed position.

Abstract: A ball valve (10) for sealing a conduit (12) is described. The ball valve includes a housing having a throughbore and a valve seat. An apertured ball element (18) is mounted within the housing and is rotatable about an axis of rotation (38) between a throughbore open and a throughbore closed position. The apertured ball element (18) has a first portion (20) and a second portion (22) coupled together which are rotatable and moveable relative to each other. The first portion has a sealing surface for engaging with the valve seat. In use, in the throughbore closed position, the second portion is moveable relative to the first portion to axially displace the first portion from the axis of rotation towards the valve seat such that the sealing surface on the first portion of the apertured ball forms a seal with valve seat.

Abstract: The well bore control valve comprises a housing (12) defining a throughbore (14), the throughbore adapted to receive a first tubular. The valve further comprises first (18) and second gates (20) located within the housing, the gates being movable in different directions transverse to the throughbore between the throughbore open position and the throughbore closed position. Movement of the gates from the throughbore open position to the throughbore closed position, in use, shares a tubular located between the gates. The valve also comprises a first seal seat (22) performing a seal of one of the gates in the throughbore closed position to seal the throughbore. In one embodiment, the gates are axially movable with respect to the throughbore.

Abstract: A tensioning apparatus for applying a substantially constant tension to a workover riser (12) includes a first portion (40) adapted to be coupled to a workover riser, a second portion (44) adapted to be coupled to a marine riser (14) and tensioning means (46) for providing relative movement between the first portion and the second portion to, in use, tension, the workover riser.

Abstract: A completion suspension valve system is described which allows a well to be suspended and desuspended remotely without a dual bore riser to the surface. This is achieved by incorporating a remotely actuatable valve into the production bore of a tubing hanger. The valve is hydraulically operable and may be controlled via the tubing hanger running tool or via the xmas tree. The valve can be closed and tested after the tubing hanger has been installed, thereby isolating the well. The dual bore riser and running tool are retrievable and the MODU type vessel is then free to continue drilling and completion operations elsewhere. The xmas tree can therefore be deployed from a workclass supply boat instead of a MODU type vessel.

Abstract: A bearing mounted ball valve (10) comprises a housing (12) having a throughbore and a valve seat (16) and an apertured ball (18) mounted within the housing in continuous engagement with the valve seat. The apertured ball is rotatable by rotation means (20), about an axis of rotation, between a throughbore open position and a throughbore closed position. The bearing mounted ball valve further comprises bearing means (26) coupled between the apertured ball and the housing for constraining the rotation of the apertured ball about the axis of rotation between the throughbore open and the throughbore closed position. In the throughbore closed position, the bearing means is adapted to release the apertured ball from the axis of rotation to permit the apertured ball to float into a sealing engagement with the valve seat.

Abstract: A lubricator system for receiving the intervention tool string includes a tubular body defining a tubular bore, and the tubular bore having a wall portion defining an aperture with a tool guide disposed in said aperture. A first sleeve surrounds the tubular body and is moveable between a first position where said aperture is covered by the first sleeve and a second position where said aperture is uncovered whereby access is provided to said tubular bore via said aperture. The system also includes a seal to allow the lubricator system to withstand operating pressures when the first sleeve is in the first position.

Abstract: A wellbore control device (10) for sealing a wellbore is described. The device has, in a preferred arrangement, two opposed cutting rams (16, 18) which are coupled to respective linkage mechanisms (26, 28). The linkage mechanisms translate axial movement of a piston into radial movement to move the rams towards each other in the device throughbore. This results in an effective wellbore control device having a compact size and shape which can be encompassed within a wellbore.