Abstract: A system is provided for switching between redundant control systems for a subsurface safety valve (SSV) while being able to isolate the closure spring from hydrostatic pressure in the control line of the system that is not being used. There are two control lines that connect to discrete operating pistons that are both coupled to the flow tube. Each operating piston is connected to a control rod with the control rods terminating near opposed ends of a pivoting member. Pushing down on one rod pushes up on the other rod so that the other rod is held supported and the hydrostatic pressure in its associated control line doesn't affect the force needed by the closure spring to close the SSV. Releasing control line pressure puts the system in neutral to allow either of the systems to be reselected.

Abstract: A combination penetration tool for access to the control system of a subsurface safety valve also has a lockout for the flapper that operates by latching into a nipple profile near its upper end as a series of collet fingers pass through a sleeve that is held in the locked position on the valve housing. One or more dogs on the collet fingers line up with the flapper already pushed open by the advancing collet fingers to push the flapper further back. A second series of dogs get past the sleeve after moving through it. With a jar up force the second series of dogs overcomes a lock on the sleeve and shifts the sleeve to overlap the open flapper and allow the lock ring that moves with the sleeve to latch into the housing. The second series of dogs is sheared off but retained by the tool for removal from the well. The penetrator portion of the tool is a known device that preferably works by jarring up.

Abstract: A combination penetration tool for access to the control system of a subsurface safety valve also has a lockout for the flapper that operates by latching into a nipple profile near its upper end as a series of collet fingers pass through a sleeve that is held in the locked position on the valve housing. One or more dogs on the collet fingers line up with the flapper already pushed open by the advancing collet fingers to push the flapper further back. A second series of dogs get past the sleeve after moving through it. With a jar up force the second series of dogs overcomes a lock on the sleeve and shifts the sleeve to overlap the open flapper and allow the lock ring that moves with the sleeve to latch into the housing. The second series of dogs is sheared off but retained by the tool for removal from the well. The penetrator portion of the tool is a known device that preferably works by jarring up.

Abstract: A subsurface safety valve features vertically stacked springs that are each independently supported in the valve housing and each having an opposite end that bears on a shoulder connected to the flow tube. When mounted this way their applied force is additive as they are in effect mounted in parallel between the housing and the flow tube for overcoming hydrostatic pressure in deep set applications that can exceed 20,000 feet. The stacking also allows the cross-sectional area of the flow tube to be maximized for a given housing outside diameter dictated by well conditions.

Abstract: A system is provided for switching between redundant control systems for a subsurface safety valve (SSV) while being able to isolate the closure spring from hydrostatic pressure in the control line of the system that is not being used. There are two control lines that connect to discrete operating pistons that are both coupled to the flow tube. Each operating piston is connected to a control rod with the control rods terminating near opposed ends of a pivoting member. Pushing down on one rod pushes up on the other rod so that the other rod is held supported and the hydrostatic pressure in its associated control line doesn't affect the force needed by the closure spring to close the SSV. Releasing control line pressure puts the system in neutral to allow either of the systems to be reselected.