A single line surface controlled, subsurface safety valve, adapted for connection in a well tubing string. The safety valve has a closure means disposed in the bore of the safety valve housing and is operable by action of control pressure fluid causing a longitudinal operator to move the closure means to an open to flow position. The control pressure fluid chamber in the safety valve is protected from well pressure by providing annular areas, between the longitudinal operator and the housing, positioned between the control pressure fluid chamber and well pressure. The annular areas are sealed from exposure to well pressure and are in fluid communication with each other. A floating piston is positioned to respond to well pressure entering the annular areas and thus move to engage and assist the operator means in closing the safety valve to flow of well fluids therethrough. Vent means is provided to prevent a hydraulic lock from retarding movement of the floating piston.
A retainer valve provides increased safety in wellsite operations. In a preferred embodiment, operation of the retainer valve may be responsive to control line pressure or to tubing pressure. The retainer valve response is controlled by several factors, among which are relative tubing and balance line pressures, and axial positions of a number of pistons relative to a tubular J-slot member. If the control and balance lines are disconnected, or otherwise unavailable for operation of the valve, it may still be operated by manipulation of the tubing pressure at the earth's surface. Thus, the valve may be opened in emergency situations in which the control and balance lines are unavailable, but operation of the valve is still needed in order to safely relieve trapped pressure in the tubing string and/or to kill the well, unlatch a subsea test tree, etc. The retainer valve is also useful as a lubricator valve.
A full opening subsurface control valve for use in subsurface closure of a well annulus. The valve includes a body with a sleeve reciprocably disposed in the valve body. The body is releasably attached to an upper tool string portion, and the sleeve is attached to a lower tool string portion. An actuator arm, mounted on the body and stationary with respect thereto, engages a ball valve element. When the body and sleeve are in a relatively converged position, the ball valve element is in a closed position. When the body and sleeve are in a relatively extended position, the ball valve is in an open position, such that the ball valve element, body and sleeve define a substantially unobstructed flow passage through the valve. A spring is utilized for relatively biasing the body and sleeve toward the converged position. The weight of the lower tool string portion overcomes the spring force such that the valve is maintained in an open position as it is longitudinally positioned in the well bore. A pressure balancing piston is provided for balancing forces exerted by test pressurization of the valve so that undesired opening of the valve is prevented.
The invention is a system and method a system used to control multiple downhole tools with one control line. The downhole tools may comprise any hydraulically actuated tools, such as valves, packers, or perforating guns. Each tool is associated with an indexer, in one embodiment, so that the tools can be operated in concert and as a system.
