Abstract: Hydraulic control assemblies for controlling the operation of one or more downhole tools. In one embodiment of the invention, a hydraulic control assembly (10) includes a tubular member in the form of tubing (12), which carries axial chambers (14), each coupled to a downhole tool and carrying a flow controlling shuttle valve (24) and a gear rod (34). Tool control fluids inlets and outlets (18, 16) are provided in communication with each chamber (14), and flow through the chamber (14) to a downhole tool to control the tool. The shuttle valve (24) is movable by the gear rod (34) to selectively allow flow of control fluid to the tool. The gear rod (34) is movable in response to applied fluid pressure.

Abstract: A downhole valve assembly (10) comprises a tubular body (12), and a valve comprising a valve member (18) and a fluid actuated valve control mechanism (14) adapted to be selectively actuated to move the valve member between an open and a closed configuration, for selectively allowing fluid flow through the body (12). A first hydraulic control conduit (41) is in fluid communication with the valve control mechanism (14) for permitting actuation of the control mechanism to move the valve member (18) to the open configuration, by application of a first control fluid. A second hydraulic control conduit (41) is in fluid communication with the valve control mechanism (14) to move the valve member (18) to the closed configuration, by application of a second control fluid.

Abstract: A downhole valve assembly (10) comprises a tubular body (12), and a valve comprising a valve member (18) and a fluid actuated valve control mechanism (14) adapted to be selectively actuated to move the valve member between an open and a closed configuration, for selectively allowing fluid flow through the body (12). A first hydraulic control conduit (41) is in fluid communication with the valve control mechanism (14) for permitting actuation Of the control mechanism to move the valve member (18) to the open configuration, by application of a first control fluid. A second hydraulic control conduit (41) is in fluid communication with the valve control mechanism (14) to move the valve member (18) to the closed configuration, by application of a second control fluid.

Abstract: Downhole apparatus in the form of a valve (140) comprises a body (148) defining a bore (168) with a curved disc closure member (142) positioned in the bore. First and second retaining members (144, 146) are positioned on respective sides of the disc (142) for retaining the disc in a closed position and to hold pressure from both sides. One of the retaining members (144) is retractable to permit opening of the valve disc (142). The disc (142) may be locked closed by locking the retractable retaining member (144) in position. On release of the member (144), application of fluid pressure to portions of the member (144) will retract the member (144).

Abstract: A method of locating a tubing string in a bore, the method comprising the steps: providing a device defining a restriction-engaging member; locating the device on the lower end of a tubing string; and then running the tubing string into the bore until the member engages a restriction in the bore and the device and the tubing is prevented from advancing further by the restriction. The member is then re-configured to permit further advancement of the device and tubing relative to the restriction and the device and tubing moved a predetermined distance relative to the restriction to position the tubing at a desired location in the bore.

Abstract: Apparatus for perforating a section of liner intersecting a hydrocarbon-bearing formation comprises a length of tubing, the wall of the tubing defining a plurality of apertures, and perforating charges being located in the apertures. The tubing is adapted for mounting on the lower end of a length of production or test tubing such that the formation fluid may flow into the tubing and then directly into the production or test tubing. The charges disintegrate on detonation to leave the apertures unobstructed and to form light or small parts which may be swept out of the well by the formation fluid. Following detonation of the charges, the flow area of the tubing corresponds to the tubing internal diameter.

Abstract: Downhole apparatus (10) for mounting on a string (12) for location in a drilled hole is provided, the apparatus comprising: a tubular body (14) defining a bore; a packer (16) mounted on the body (14) for sealing the annulus between the body (14) and the wall of the hole; a plug or valve (18) for closing the body bore (14) below the packer (16); a fluid actuated valve (20) in the body between the bore closing valve (18) and the packer (16) for permitting selective fluid communication between the body bore and the exterior of the body, and an arrangement (22) for transferring fluid pressure from above the packer (16) to the valve (20), whereby fluid pressure applied to the annulus above the packer (16) may be used to operate the valve (20).

Abstract: Downhole apparatus in the form of a valve (140) comprises a body (148) defining a bore (168) with a curved disc closure member (142) positioned in the bore. First and second retaining members (144, 146) are positioned on respective sides of the disc (142) for retaining the disc in a closed position and to hold pressure from both sides. One of the retaining members (144) is retractable to permit opening of the valve disc (142). The disc (142) may be locked closed by locking the retractable retaining member (144) in position, On release of the member (144), application of fluid pressure to portions of the member (144) will retract the member (144).

Abstract: Downhole apparatus in the form of a valve (140) comprises a body (148) defining a bore (168) with a curved disc closure member (142) positioned in the bore. First and second retaining members (144, 146) are positioned on respective sides of the disc (142) for retaining the disc in a closed position and to hold pressure from both sides. One of the retaining members (144) is retractable to permit opening of the valve disc (142). The disc (142) may be locked closed by locking the retractable retaining member (144) in position. On release of the member (144), application of fluid pressure to portions of the member (144) will retract the member (144).

Abstract: Apparatus for perforating a section of liner intersecting a hydrocarbon-bearing formation comprises a length of tubing, the wall of the tubing defining a plurality of apertures, and perforating charges being located in the apertures. The tubing is adapted for mounting on the lower end of a length of production or test tubing such that the formation fluid may flow into the tubing and then directly into the production or test tubing. The charges disintegrate on detonation to leave the apertures unobstructed and to form light or small parts which may be swept out of the well by the formation fluid. Following detonation of the charges, the flow area of the tubing corresponds to the tubing internal diameter.

Abstract: Apparatus for use in setting packers and other fluid actuated devices includes a tubular body (222), a valve (228) for controlling the flow of well fluid through a port (234) in the body (222) and a valve actuator (224) mounted on the body (222) and movable relative thereto, to open the valve (228) by application of well fluid pressure. The well fluid may flow through the open valve (228) to set a packer or actuate a device.