Abstract: The present invention generally relates to a subsurface safety valve configured to control fluid flow through a production tubing string. In one aspect, a safety valve for deployment beneath a surface of a wellbore is provided. The valve includes a control piston and a balance piston. The valve is configured to be connected to a controller at the surface by a control line so that the control piston is actuatable between a first position and a second position in response to receiving pressurized fluid from the controller through the control line. The balance piston is configured to compensate for hydrostatic pressure in the control line. The valve may have a bore therethrough and the control piston may be configured to utilize tubing pressure within the valve bore to urge the control piston towards the second position.

Abstract: The present invention generally relates to a subsurface safety valve configured to control fluid flow through a production tubing string. In one aspect, a safety valve for deployment beneath a surface of a wellbore is provided. The valve includes a control piston and a balance piston. The valve is configured to be connected to a controller at the surface by a control line so that the control piston is actuatable between a first position and a second position in response to receiving pressurized fluid from the controller through the control line. The balance piston is configured to compensate for hydrostatic pressure in the control line. The valve may have a bore therethrough and the control piston may be configured to utilize tubing pressure within the valve bore to urge the control piston towards the second position.

Abstract: A tool for generating a force downhole comprises a body, a longitudinally movable activating member mounted to the body, and a longitudinally movable driven member also mounted to the body. The driven member is operatively associated with the activating member such that on translation of the activating member in one axial direction, the driven member is translated in an opposite axial direction. The tool may be utilised to convert a pulling action, applied by a spoolable member, to a pushing action, useful in disengaging a downhole lock.