Abstract: A control system automatically operates a subsea well control device on detecting that a load in an Intervention Riser System (IRS) coupled to the subsea well control device has reached a threshold. The control system has a first control unit to detect that the load in the IRS has reached the threshold and a second control unit triggering actuation of the subsea well control device. The first control unit is in communication with the second control unit and issues an activation command to the second control unit to cause it to trigger actuation of the subsea well control device. The first control unit automatically issues the activation command to the second control unit upon detecting that the load in the IRS has reached the threshold, to trigger actuation of the subsea well control device prior to structural failure of an IRS.

Abstract: A hydraulic protection system for preventing collapse of a hydraulic line is provided. The system includes a pressure sensing assembly which is arranged to monitor a pressure differential between fluid external to and fluid contained within the hydraulic line; a pressure compensation assembly adapted to be coupled to the hydraulic line. In the event of a loss of pressure in the hydraulic line occurring, the pressure compensation assembly employs the pressure of the fluid external to the hydraulic line to increase the pressure of the fluid contained within the hydraulic line. The system is arranged so that the pressure compensation assembly is operated when the pressure differential monitored by the pressure sensing assembly reaches a predetermined level, which is below a collapse pressure of the hydraulic line, so that exposure of the hydraulic line to the collapse pressure is avoided.

Abstract: A valve assembly for controlling fluid communication along a well tubular that includes hydraulically operated valve that includes a valve member movable between open and closed positions, and a hydraulic actuator for moving the valve member; a control system for selectively controlling the flow of hydraulic fluid to and from the actuator; a vent chamber for selectively receiving hydraulic fluid exhausted from the actuator when the valve member is moved to its closed position; and a vent conduit for selectively receiving hydraulic fluid exhausted from the actuator when the valve member is moved to its closed position. The control system has a first valve closing state in which the vent chamber is isolated from the actuator. The control system has a second valve closing state in which fluid exhausted from the actuator during movement of the valve member to its closed position is vented into the vent chamber.

Abstract: A valve assembly (100) is disclosed, for controlling fluid communication along a well tubular (10). The valve assembly comprises: a hydraulically operated valve (40, 42) comprising a valve member (41, 43) which is movable between open and closed positions, and a hydraulic actuator (148) associated with the valve member for moving the valve member between these positions; a control system (146) for selectively controlling the flow of hydraulic fluid to and from the actuator, to operate the valve; a vent chamber (84) operatively connectable to the actuator, for selectively receiving hydraulic fluid exhausted from the actuator when the valve member is moved to its closed position; and a vent conduit (172) operatively connectable to the actuator, for selectively receiving hydraulic fluid exhausted from the actuator when the valve member is moved to its closed position, the vent conduit being exposed to fluid external to the valve assembly at the prevailing external pressure.

Abstract: Valve assemblies are disclosed for use in the oil and gas industry. A disclosed valve assembly includes a housing having a bore; a valve member arranged within the housing which is movable relative to the bore between open and closed positions. The valve member includes a cutting feature and a sealing surface; a cutting component that cooperates with the cutting feature when the valve member is in moved to the closed position; a first seal element arranged within the housing and providing a first seal relative to the sealing surface; and a second seal element arranged within the housing and providing a second seal relative to the sealing surface. The second seal element is movable relative to the housing bore between first and second positions. A corresponding method of controlling communication along a bore of a housing is also disclosed.

Abstract: A control system automatically operates a subsea well control device on detecting that a load in an Intervention Riser System (IRS) coupled to the subsea well control device has reached a threshold. The control system has a first control unit to detect that the load in the IRS has reached the threshold and a second control unit triggering actuation of the subsea well control device. The first control unit is in communication with the second control unit and issues an activation command to the second control unit to cause it to trigger actuation of the subsea well control device. The first control unit automatically issues the activation command to the second control unit upon detecting that the load in the IRS has reached the threshold, to trigger actuation of the subsea well control device prior to structural failure of an IRS.

Abstract: A control system for automatically operating a well control device located in a subsea blow-out preventer (BOP), has a first control unit and a second control unit. The first control unit is connected to the second control unit and issues an activation command to the second control unit to cause it to trigger actuation of the well control device, and the first control unit is configured to automatically issue the activation command to the second control unit on detecting issue of the signal indicative of a requirement to trigger actuation of the subsea BOP shear mechanism.

Abstract: A hydraulic protection system (46) for preventing collapse of a hydraulic line (38). The system comprises a pressure sensing assembly (50) which is arranged to monitor a pressure differential between fluid external to the hydraulic line and fluid contained within the hydraulic line; and a pressure compensation assembly (52) which is adapted to be coupled to the hydraulic line and which is exposed to the fluid external to the hydraulic line. The pressure compensation assembly (52) is operable to employ the pressure of the fluid external to the hydraulic line to increase the pressure of the fluid contained within the hydraulic line and thereby compensate for the loss. The system is arranged so that the pressure compensation assembly (52) is operated when the pressure differential monitored by the pressure sensing assembly (50) reaches a predetermined level, which is below a collapse pressure of the hydraulic line.

Abstract: A valve seat for a valve is disclosed, the valve seat facilitating cutting of a body located within the seat. The valve seat includes a sealing surface for sealing with a valve member and an annular cutting component having a plurality of cutting teeth. The cutting teeth are circumferentially spaced and each defines an elongate crest. A valve is disclosed having a housing with a bore), a valve member and the valve seat. The valve seat is arranged within the housing in communication with the housing bore. The valve member is movable relative to the housing between an open position and a closed position.

Abstract: A valve seat for a valve is disclosed, the valve seat facilitating cutting of a body located within the seat. The valve seat includes a sealing surface for sealing with a valve member and an annular cutting component having a plurality of cutting teeth. The cutting teeth are circumferentially spaced and each defines an elongate crest. A valve is disclosed having a housing with a bore), a valve member and the valve seat. The valve seat is arranged within the housing in communication with the housing bore. The valve member is movable relative to the housing between an open position and a closed position.

Abstract: A ball valve is provided. The ball valve includes a housing, a ball seat arranged in the housing, a ball member mounted within the housing and being rotatable relative to the ball seat between open and closed positions, the ball seat and ball member defining respective through bores, the ball member including a sealing surface, a bore surface and a leading edge surface extending between the sealing surface and the bore surface, the leading edge surface being configured to cut a body extending at least partially through the valve upon closure of the ball member, wherein said leading edge surface is truncated. The ball member may include a relief region proximate the leading edge surface.

Abstract: A ball valve is provided. The ball valve includes a housing, a ball seat arranged in the housing, a ball member mounted within the housing and being rotatable relative to the ball seat between open and closed positions, the ball seat and ball member defining respective through bores, the ball member including a sealing surface, a bore surface and a leading edge surface extending between the sealing surface and the bore surface, the leading edge surface being configured to cut a body extending at least partially through the valve upon closure of the ball member, wherein said leading edge surface is truncated. The ball member may include a relief region proximate the leading edge surface.