A system including a releasable connector having a housing and a split ring, and a complementary mandrel that is attachable/detachable from the connector, is provided. The mandrel is designed to be received into the housing such that a portion of the mandrel extends out of the housing for connection to a tool. The split ring is disposed in an annular space between the housing and the mandrel when the mandrel is in the housing. The split ring includes at least one set of threads and a detent formed on a radially internal surface, and the mandrel includes complementary threads. The threads on the split ring fully engage the complementary threads on the mandrel when the mandrel is in a particular axial position within the housing. The detent prevents the split ring from collapsing into engagement with the threads on the mandrel until the mandrel is in a desired axial position.

A subsea tree including a fluid swivel, the fluid swivel comprising: (a) a fixed inner body defining an inlet for fluid communication with a production conduit fora subsea well; (b) a rotatable outer body defining an outlet and an attachment point for fluid communication with a riser; (c) a first interface between the fixed inner body and the rotatable outer body defining a fluid chamber in fluid communication with the inlet and the outlet; and (d) a first seal between the fixed inner body and the rotatable outer body; wherein, when the fluid swivel is attached to the riser, the riser is capable of rotational movement around the subsea tree.

It is described a subsea electric actuator (100) operating a linear valve (200), the actuator (100) comprising a roller-screw (2) for translating a rotational movement of a motor (3) to a linear movement of a gate rod (4) operating the valve (200), the actuator (100) comprising: —an actuator housing (101); —an outer roller screw part (2′) rotationally connected to the motor (3) and comprising internal threads forming a first part of a first connection (10), —an inner roller screw part (2″) comprising external threads forming a second part of the first connection (10) and being arranged inside the outer roller screw part (2′), a surface of the inner roller screw part (2″) having a first interface forming a first part of a second connection (20′; 20″) connecting the inner roller screw part (2″) to a non-rotational part of the actuator (100), the second connection (20′, 20″) is configured to rotationally lock the inner roller screw part (2′) giving linear movement of the inner roller screw part (2″) when the outer roller screw (2′) is rotated, —a gate rod (4) arranged axially movable inside the inner roller screw part (2″), the external surface of the gate rod (4) comprising an interface forming a first part of a third connection (30′; 30″), —an override housing (6) arranged outside the gate rod (4) and adjacent the inner roller screw part (2″) forming an axial stop for the inner roller screw part (2″), the override housing (6) comprising an interface forming a second part of the third connection (30′; 30″), and wherein, when the third connection (30′; 30″) is connected, the inner roller screw part (2″) is locked to the gate rod (4) such that the gate rod (4) follows any axial movement of the inner roller screw part (2″), and when the third connection (30′; 30″) is disconnected, the gate rod (4) is allowed to move in the axial direction relative the inner roller screw part (2″) such that the linear valve (200) can be operated independently of the motor (3), outer roller screw part (2′) and inner roller screw part (2″). It is further described a method of performing override of a subsea electric actuator (100).

It is described a subsea electric actuator (100) operating a linear valve (200), the actuator (100) comprising a roller-screw (2) for translating a rotational movement of a motor (3) to a linear movement of a gate rod (4) operating the valve (200), the actuator (100) comprising: —an actuator housing (101); —an outer roller screw part (2′) rotationally connected to the motor (3) and comprising internal threads forming a first part of a first connection (10), —an inner roller screw part (2″) comprising external threads forming a second part of the first connection (10) and being arranged inside the outer roller screw part (2′), a surface of the inner roller screw part (2″) having a first interface forming a first part of a second connection (20′; 20″) connecting the inner roller screw part (2″) to a non-rotational part of the actuator (100), the second connection (20′, 20″) is configured to rotationally lock the inner roller screw part (2′) giving linear movement of the inner roller screw part (2″) when the outer roller screw (2′) is rotated, —a gate rod (4) arranged axially movable inside the inner roller screw part (2″), the external surface of the gate rod (4) comprising an interface forming a first part of a third connection (30′; 30″), —an override housing (6) arranged outside the gate rod (4) and adjacent the inner roller screw part (2″) forming an axial stop for the inner roller screw part (2″), the override housing (6) comprising an interface forming a second part of the third connection (30′; 30″), and wherein, when the third connection (30′; 30″) is connected, the inner roller screw part (2″) is locked to the gate rod (4) such that the gate rod (4) follows any axial movement of the inner roller screw part (2″), and when the third connection (30′; 30″) is disconnected, the gate rod (4) is allowed to move in the axial direction relative the inner roller screw part (2″) such that the linear valve (200) can be operated independently of the motor (3), outer roller screw part (2′) and inner roller screw part (2″). It is further described a method of performing override of a subsea electric actuator (100).

A testable back pressure valve for controlling fluid flow through a bore of a component installed in a well bore is disclosed. The back pressure valve includes a valve body which is configured to be secured in the bore, a flow bore which extends through the valve body, at least a first body seal which is configured to seal the valve body to the bore, and a poppet which is movably positioned in the valve body. At least a first poppet seal is sealingly engaged between the poppet and the valve body when the poppet is in the closed position, and a test port extends through the valve body to below the first poppet seal when the poppet is in the closed position. Thus, with the back pressure valve installed in the flow bore and the poppet in the closed position, the first poppet seal can be pressure tested by communicating test pressure through the test port to below the first poppet seal.

A subsea test tree assembly is provided which includes at least one subsea test tree or SSTT, the SSTT including a valve having at least one of a cutting function and a sealing function, the valve being movable between an open position and a closed position via hydraulic fluid supplied to the valve through control lines; and a control system including a source of hydraulic fluid, the control system being arranged to supply hydraulic fluid from the source of hydraulic fluid to the valve of the at least one SSTT on detecting that the control lines have been sheared, to automatically move the valve to the closed position. A method of controlling a well using an SSTT assembly is also provided.

A valve apparatus comprises a housing defining a flowpath extending between a valve inlet and a valve outlet and an access port formed in a wall of the housing separately from the valve inlet and the valve outlet to provide access to the flowpath at a location which is intermediate the valve inlet and valve outlet. A valve mechanism is mounted within the flowpath, wherein the valve mechanism in insertable through the access port.

A system including a releasable connector having a housing and a split ring, and a complementary mandrel that is attachable/detachable from the connector, is provided. The mandrel is designed to be received into the housing such that a portion of the mandrel extends out of the housing for connection to a tool. The split ring is disposed in an annular space between the housing and the mandrel when the mandrel is in the housing. The split ring includes at least one set of threads and a detent formed on a radially internal surface, and the mandrel includes complementary threads. The threads on the split ring fully engage the complementary threads on the mandrel when the mandrel is in a particular axial position within the housing. The detent prevents the split ring from collapsing into engagement with the threads on the mandrel until the mandrel is in a desired axial position.

The disclosure provides a downhole completion device for use in a wellbore and a subterranean production well. In one embodiment, the downhole completion device includes: (1) a hydraulic line controlled device, the hydraulic line controlled device having a control line port and one or more fluid leakage paths, and (2) a density barrier having first and second ends, wherein the first end is coupled to the control line port and the second end is configured to couple to a control line extending from a surface installation, the density barrier having an axial loop relative to the hydraulic line controlled device and positioned below the fluid leakage path, thereby preventing migration of leakage fluid from the one or more fluid leakage paths to the surface installation.

A modular hydraulic intensification system includes a housing configured to be deployed within a subsea landing string. The modular hydraulic intensification system also includes multiple hydraulic intensifiers positioned within the housing, wherein each hydraulic intensifier includes a first chamber configured to fluidly couple to a hydraulic fluid supply and a second chamber configured to fluidly couple to one or more landing string valves within a lower portion of the subsea landing string. The modular hydraulic intensification system further includes a shuttle valve fluidly coupled to the respective second chambers of the multiple hydraulic intensifiers, wherein the shuttle valve is configured to enable flow of an output fluid across the shuttle valve from the respective second chambers of the multiple hydraulic intensifiers and to block backflow of the output fluid across the shuttle valve toward the respective second chambers of the multiple of hydraulic intensifiers.