Abstract: A valve apparatus comprises a valve body defining a flow path therethrough, a valve member mounted within the valve body, and an actuator assembly mounted internally within the valve body. The actuator assembly comprises a piston bore and piston member defining a piston chamber therebetween, wherein at least one of the piston bore and piston member is engaged or associated with the valve member such that the valve member is moveable in accordance with fluid pressure within the piston chamber to selectively occlude the flow path.

Abstract: A valve apparatus comprises a valve body defining a flow path therethrough, a valve member mounted within the valve body, and an actuator assembly mounted internally within the valve body. The actuator assembly comprises a piston bore and piston member defining a piston chamber therebetween, wherein at least one of the piston bore and piston member is engaged or associated with the valve member such that the valve member is moveable in accordance with fluid pressure within the piston chamber to selectively occlude the flow path.

Abstract: A valve apparatus comprises a valve body defining a flow path therethrough, a valve member mounted within the valve body, and an actuator assembly mounted internally within the valve body. The actuator assembly comprises a piston bore and piston member defining a piston chamber therebetween, wherein at least one of the piston bore and piston member is engaged or associated with the valve member such that the valve member is moveable in accordance with fluid pressure within the piston chamber to selectively occlude the flow path.

Abstract: A downhole valve, such as a safety valve or sub-sea safety valve (SSSV). The downhole valve comprising: a housing; a flow path between a valve inlet and a valve outlet; a valve mechanism; and a piston member; wherein the valve mechanism is operable by actuation of the piston member to selectively open and close the flow path between the valve inlet and valve outlet; and the piston member is actuatable by a pressure differential between an annulus pressure at the valve and a pressure at the valve outlet and/or in a portion of the flow path closest to the valve outlet. The valve can comprise an opening for receiving the annular pressure that is isolated from the valve inlet and valve outlet. The downhole valve can be configured such that it prevents operation of the valve mechanism to open and/or close the flow path by a pressure differential between the valve inlet and valve outlet.

Abstract: A screen assembly, such as a downhole/sand screen assembly, comprising first and second screen portions or screens longitudinally coupled together, wherein there is provided a fluid flow path between the first and second screen portions or screen. Optionally, the first and second sleeves are coupled or connected by a centraliser or further sleeve or screen, and/or optionally by or via first and second support ring.

Abstract: A valve apparatus comprises a valve body defining a flow path therethrough, a valve member mounted within the valve body, and an actuator assembly mounted internally within the valve body. The actuator assembly comprises a piston bore and piston member defining a piston chamber therebetween, wherein at least one of the piston bore and piston member is engaged or associated with the valve member such that the valve member is moveable in accordance with fluid pressure within the piston chamber to selectively occlude the flow path.

Abstract: A downhole valve, such as a safety valve or sub-sea safety valve (SSSV). The downhole valve comprising: a housing; a flow path between a valve inlet and a valve outlet; a valve mechanism; and a piston member; wherein the valve mechanism is operable by actuation of the piston member to selectively open and close the flow path between the valve inlet and valve outlet; and the piston member is actuatable by a pressure differential between an annulus pressure at the valve and a pressure at the valve outlet and/or in a portion of the flow path closest to the valve outlet. The valve can comprise an opening for receiving the annular pressure that is isolated from the valve inlet and valve outlet. The downhole valve can be configured such that it prevents operation of the valve mechanism to open and/or close the flow path by a pressure differential between the valve inlet and valve outlet.

Abstract: A screen assembly, such as a downhole/sand screen assembly, comprising first and second screen portions or screens longitudinally coupled together, wherein there is provided a fluid flow path between the first and second screen portions or screen. Optionally, the first and second sleeves are coupled or connected by a centraliser or further sleeve or screen, and/or optionally by or via first and second support ring.

Abstract: A screen assembly, such as a downhole/sand screen assembly, comprising first and second screen portions or screens longitudinally coupled together, wherein there is provided a fluid flow path between the first and second screen portions or screen. Optionally, the first and second sleeves are coupled or connected by a centralizer or further sleeve or screen, and/or optionally by or via first and second support ring.

Abstract: A screen assembly, such as a downhole/sand screen assembly, comprising first and second screen portions or screens longitudinally coupled together, wherein there is provided a fluid flow path between the first and second screen portions or screen. Optionally, the first and second sleeves are coupled or connected by a centralizer or further sleeve or screen, and/or optionally by or via first and second support ring.

Abstract: A method in a clocked integrated circuit receiving an input clock signal having a clock frequency and a command signal for accessing a memory element in the clocked integrated circuit. The method detects the input clock signal having a clock frequency above or below a frequency threshold. The method generates a clock detect output signal having a first logical state in response to the clock frequency being below the frequency threshold and generates the clock detect output signal having a second logical state in response to the clock frequency being above the frequency threshold. The method delays the command signal by a first timing latency to generate a timing adjusted control signal where the first timing latency is one or more clock periods of the input clock signal. Finally, the method adjusts the first timing latency in response to the clock detect output signal.

Abstract: A method in a clocked integrated circuit receiving an input clock signal having a clock frequency and a command signal for accessing a memory element in the clocked integrated circuit. The method detects the input clock signal having a clock frequency above or below a frequency threshold. The method generates a clock detect output signal having a first logical state in response to the clock frequency being below the frequency threshold and generates the clock detect output signal having a second logical state in response to the clock frequency being above the frequency threshold. The method delays the command signal by a first timing latency to generate a timing adjusted control signal where the first timing latency is one or more clock periods of the input clock signal. Finally, the method adjusts the first timing latency in response to the clock detect output signal.

Abstract: A screen assembly, such as a downhole/sand screen assembly, comprising first and second screen portions or screens longitudinally coupled together, wherein there is provided a fluid flow path between the first and second screen portions or screen. Optionally, the first and second sleeves are coupled or connected by a centralizer or further sleeve or screen, and/or optionally by or via first and second support ring.

Abstract: A method in a clocked integrated circuit receiving an input clock signal having a clock frequency and a command signal for accessing a memory element in the clocked integrated circuit. The method detects the input clock signal having a clock frequency above or below a frequency threshold. The method generates a clock detect output signal having a first logical state in response to the clock frequency being below the frequency threshold and generates the clock detect output signal having a second logical state in response to the clock frequency being above the frequency threshold. The method delays the command signal by a first timing latency to generate a timing adjusted control signal where the first timing latency is one or more clock periods of the input clock signal. Finally, the method adjusts the first timing latency in response to the clock detect output signal.

Abstract: A downhole arrangement (32) comprises first (34) and second (41) members, a lock profile (4) fixed relative to one of the first and second members, and a lock member (10) for engaging the at least one lock profile. A release member (40) is provided which is moveable to selectively lock the lock member in engagement with the lock profile so as to selectively secure the second member relative to the first member. Such a downhole arrangement may permit a releasable connection between the first and second members.

Abstract: A downhole actuator (30) comprises a tubular housing (34) which includes an indexing profile (42) on an inner surface thereof, and an indexing sleeve (46) mounted within the housing (34). The indexing sleeve (46) comprises an engaging arrangement including first and second axially spaced engagement members (52, 54) which cooperate with the indexing profile (42) of the housing (34) to be sequentially engaged by an actuation object (48) passing through a central bore (50) of the indexing sleeve (46) to drive the indexing sleeve (46) one discrete step of movement through the housing (34) towards an actuation site.

Abstract: A screen assembly, such as a downhole/sand screen assembly, comprising first and second screen portions or screens longitudinally coupled together, wherein there is provided a fluid flow path between the first and second screen portions or screen. Optionally, the first and second sleeves are coupled or connected by a centralizer or further sleeve or screen, and/or optionally by or via first and second support ring.

Abstract: A downhole tool (32) comprises a tool housing (34) defining a central bore (35) and including a fluid port (20), and a valve member (40) mounted within the housing (34) and being movable from a closed position in which the fluid port (20) is blocked to an open position in which the fluid port (20) is opened. The tool (32) further comprises a catching arrangement (41) mounted within the housing (34) and comprising one or more radially movable seat members (106), and being configurable from a free configuration in which the seat members (106) permit an object (48) to pass through the tool (32), to a catching configuration in which the seat members (106) catch an object (48) passing through the tool (32).

Abstract: A downhole tool (32) comprises a tool housing (34) defining a central bore (35) and including a fluid port (20), and a valve member (40) mounted within the housing (34) and being moveable from a closed position in which the fluid port (20) is blocked to an open position in which the fluid port (20) is opened. The tool (32) further comprises a catching arrangement (41) mounted within the housing (34) and comprising one or more radially moveable seat members (106), and being configurable from a free configuration in which the seat members (106) permit an object (48) to pass through the tool (32), to a catching configuration in which the seat members (106) catch an object (48) passing through the tool (32).

Abstract: A clock timing adjust circuit is incorporated in a clocked integrated circuit to detect an input clock frequency and to adjust the timing latency of an internal control signal for accessing a memory element in the clocked integrated circuit. The clock timing adjust circuit introduces an adjustable timing latency to an internal control signal derived from the command signal. The clock timing adjust circuit operates to adjust the timing latency of the control signal to cause clock based operations to either be advanced or delayed by one or more clock cycles in response to the clock frequency detection. In one embodiment, the clock timing adjust circuit includes a clock frequency detect circuit and a latency adjust circuit. The clock timing adjust circuit can operate at both high and low clock frequencies to ensure that undesired data collision events are obviated without introducing unnecessary delays.