Abstract: A riser weak link (10) is described. The riser weak link comprises an upper housing (16) for connecting to a riser upper section (12), a lower housing (18) for connecting to a riser lower section (14), at least one connection device for releasably connecting the upper and lower housings, and a pressure application device (24) adapted to apply a coupling force to the upper housing to at least partially counter a separation force applied, in use, by well pressure, the well pressure separation force acting to separate the upper and lower housings.

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 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: 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 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 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 ereventer 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 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: A lubricator system for receiving the intervention tool string is described. The system 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. Embodiments of the invention are described.

Abstract: A riser control device, particularly designed to be used in connection with spool or horizontal production trees (12) for wells in sub-sea oil and gas installations. Within a housing (1,2) of the device is provided, in opposed direction, radially movable pair of rams (6) for isolating (sealing off) the well and simultaniously, in opposed direction a radially movable pair of shear blades (7) for cutting off an intervention string or the like. The rams (6) and blades (7) are driven by means of a vertically disposed actuator (8,9,23) integrated in the housing (1, 2). The actuator may be in the form of a hydralically driven annular piston (23)/annular chamber (29,30) device, which via piston rods (14) and translation beams (8) transforms the movement of the piston (23) to open or close the rams (6) and shear blades (7).

Abstract: A self-contained well intervention system which can be deployed from a lightweight vessel and coupled directly to a wellhead is described. The system includes valve means for providing a suitable well barrier and sealing the intervention system to allow an emergency disconnect. Within the intervention system, a tool magazine is provided which contains at least one deployable intervention tool. The intervention system also contains a tool selection and deployment means based on a winch located in close proximity to the magazine and which is operable from the surface for selecting a particular tool from the magazine and for deploying the selected tool through the intervention system and the wellhead into the well. The tool magazine has a plurality of magazine pockets each of which may have a deployable tool therein.

Abstract: A well testing system and well testing method is described which can be operated as a closed system with no production of hydrocarbons outside the well or gas can be separated and flared at surface giving minimal environmental impact with the liquid hydrocarbon being re-injected. This is achieved by providing a string with at least two well conduits which may be arranged in a concentric or non-concentric parallel configuration. One conduit is used to produce formation fluids to surface or to produce/store unrepresentative initial flow products and the other conduit is used to store formation fluid. The storage conduit can be filled from the top (surface) or the bottom of the well. In a preferred arrangement a valve is provided between the storage conduit and the well annulus for well pressure control, and a shut-in or test valve, which is controllable from surface, is disposed in the non-storage production conduit.

Abstract: A well testing system and well testing method is described which can be operated as a closed system with no production of hydrocarbons outside the well or gas can be separated and flared at surface giving minimal environmental impact with the liquid hydrocarbon being re-injected. This is achieved by providing a string with at least two well conduits which may be arranged in a concentric or non-concentric parallel configuration. One conduit is used to produce formation fluids to surface or to produce/store unrepresentative initial flow products and the other conduit is used to store formation fluid. The storage conduit can be filled from the top (surface) or the bottom of the well. In a preferred arrangement a valve is provided between the storage conduit and the well annulus for well pressure control, and a shut-in or test valve, which is controllable from surface, is disposed in the non-storage production conduit.

Abstract: A ball valve (10) is described which has a ball valve retaining mechanism which, when subject to very slight movement, allows a ball element (20) to be unloaded off a valve seat (48) during rotation, but remain in contact with the valve seat (48) so as to prevent debris ingress between the ball and the valve seat, and to instantaneously reload onto the valve seat upon the event of closure. This instantaneous and automatic redirection of the reaction load path at the occurrence of closure provides an effective seal against high pressure aggressive fluids to prevent fluid escaping beyond the valve components whilst, at the same time, allowing effective rotational movement of the valve to occur without providing rotational reliability. This solution allows conflicting load paths through the valve to be resolved, namely through the trunnion during rotation and through the valve seat during sealing.

Abstract: An electrical connector system is described for use in subsea environments for providing electrical connection through the wellhead into a tubular element with apertures for carrying electrical cables downhole. The system includes a circumferential electrically conductor ring which is coupled to, and insulated from, a tubular subsea element such as a tubing hanger, by an elastomeric electrically insulating sealing element, surrounding the conductor ring. The conductor ring is coupled to an electrical annular connector and is adapted to receive an electrical connector of a horizontally mounted electrical connector assembly which is hydraulically actuated to penetrate the elastomeric element in the direction transverse to the longitudinal axis of the tubular element to make electrical contact with the conductor ring.

Abstract: A fluid-tight coupling (2) for connecting opposite ends of the pipe section (4, 6) to provide a fluid-tight AI seal is described. The fluid-tight seal between the upper and lower tubular sections is provided by an upper and a lower metal-to-metal seal produced respectively between a lower sealing surface (10) of the upper pipe section (4) and an upper sealing surface (12) of an annular interface member (8) and an upper sealing surface (14) of the lower section (6) and a lower sealing surface (16) of the annular interface member (8). The metal-to-metal seals are produced and maintained by a collar (20) arranged coaxially about the coupling region of the tubular sections.

Abstract: A Christmas tree (16) is based on a dual bore sub-sea test tree. The Christmas tree consists of a Christmas tree housing (56), which connects to a wellhead (44), a Christmas tree valve block assembly (62) disposed in the housing (56) and a tree cap (84) which connects to the housing (56) and valve block assembly (62). In a preferred embodiment the valve block assembly (62) has a main production bore (70) with two valves (72,74) in series and two auxiliary bores (76,96). One auxiliary bore (96) has a valve (98) for facilitating control of the annulus bore (96) whereas the other annulus bore (76) has no valve and provides a pathway for an electrical submersible cable (66) to a pump. The valves (72,74,98) are actuatable via control from an umbilical (94) and provide the facility to seal the production and annulus access bores to meet statutory requirements. A tubing hanger is not required.

Abstract: A bore selection apparatus (38) is described for facilitating access from a single bore riser to a production bore (34,34a) or annulus bore (36, 36a) without using a wireline-run whipstock. The bore selector apparatus disposed within the bore of a BOP stack (12) and which can be coupled between casing or tubing and a sub-sea test tree. The bore selector apparatus (38) can be actuated from the surface or from an ROV to provide a coupling between the tubing bore (44) and the production bore (34, 34a) or between the tubing bore (44) and the smaller annulus bore (36, 36a).

Abstract: A wellhead cap assembly (10) includes a high security barrier (16) for installation onto a wellhead (12) containing any leakage safely and for permitting the installation of a subsea xmas tree onto the wellhead (12) whilst, simultaneously, providing means for containing full pressure control during rectification of the leak. The barrier (16) is provided by an internal tree cap which allows pressure between the top of the tubing hanger (34) and the underside of the tree cap (16) to be monitored by pressure monitoring means (20) via a port (29) in the assembly (10) and, in addition, in the event the presence of well bore fluids is detected indicating that leakage has occurred, the cap assembly allows intervention in order to rectify the leakage.

Abstract: A single bore riser system is disclosed which is based on a dual bore completion tree. An eccentric offset sub is coupled to the top of the tree and which can be sealed by BOP pipe rams. The completion tree has a main bore and an auxiliary bore with ball valves located in the respective bores. A remotely actuatable annulus plug is located in the bottom of the annulus bore and is moveable between a first position allowing fluid flow through the annulus bore and a second position sealing the annulus bore to provide control of various operations. Embodiments of the invention are described.

Abstract: An improved sub-sea Xmas tree consists of a wellhead connector, a cylindrical structural housing and a tree cap mounted on top of the housing. A dual bore sub-sea completion test tree is disposed in the housing and it has a main production bore with serial ball valves for controlling fluid flow in the production flow path of an annuus bore with a ball valve therein. The ball valves are independently and remotely actuatable by a remotely operated vehicle (ROV) override system to control communication through the Xmas tree and to comply with various regulatory standards. A cross-over valve is provided between the main bore and the annulus bore to allow fluid passage for well kill operations.