摘要:
A sensor and transmitter is employed with a pressurized chamber of a downhole tool to be able to tell at a glance when the tool is delivered for service that it is properly charged. The sensor and transmitter can be integrated within the tool so as to be protected from damage during run in. While in service the sensor and transmitter can monitor pressure in real time and include a capability to send surface signals for real time monitoring of chamber pressures corrected for the service depth, temperature and density of the hydraulic fluid, for example. The signal can be acoustic through the control line or the annulus or delivered through a fiber optic cable or signal wire run in the hydraulic control line, an auxiliary line or through the annulus.
摘要:
A sensor and transmitter is employed with a pressurized chamber of a downhole tool to be able to tell at a glance when the tool is delivered for service that it is properly charged. The sensor and transmitter can be integrated within the tool so as to be protected from damage during run in. While in service the sensor and transmitter can monitor pressure in real time and include a capability to send surface signals for real time monitoring of chamber pressures corrected for the service depth, temperature and density of the hydraulic fluid, for example. The signal can be acoustic through the control line or the annulus or delivered through a fiber optic cable or signal wire run in the hydraulic control line, an auxiliary line or through the annulus.
摘要:
A sensor and transmitter is employed with a pressurized chamber of a downhole tool to be able to tell at a glance when the tool is delivered for service that it is properly charged. The sensor and transmitter can be integrated within the tool so as to be protected from damage during run in. While in service the sensor and transmitter can monitor pressure in real time and include a capability to send surface signals for real time monitoring of chamber pressures corrected for the service depth, temperature and density of the hydraulic fluid, for example. The signal can be acoustic through the control line or the annulus or delivered through a fiber optic cable or signal wire run in the hydraulic control line, an auxiliary line or through the annulus.
摘要:
A sensor and transmitter is employed with a pressurized chamber of a downhole tool to be able to tell at a glance when the tool is delivered for service that it is properly charged. The sensor and transmitter can be integrated within the tool so as to be protected from damage during run in. While in service the sensor and transmitter can monitor pressure in real time and include a capability to send surface signals for real time monitoring of chamber pressures corrected for the service depth, temperature and density of the hydraulic fluid, for example. The signal can be acoustic through the control line or the annulus or delivered through a fiber optic cable or signal wire run in the hydraulic control line, an auxiliary line or through the annulus.
摘要:
A shape memory material is used for a power spring in a subsurface safety valve. The spring is sized for the force it will deliver when it goes past its transition temperature and reverts to an original shape. The force released by having the spring pass its transition temperature holds the valve closed against hydrostatic pressure. Since the force exerted by the spring does not increase as the valve opens less force is required to hold the valve in the open position, thus lowering opening pressure. The trigger to cross the transition temperature comes from the expected temperature of well fluids at the mounting position of the subsurface safety valve. Other downhole applications are anticipated.
摘要:
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.
摘要:
A control system can be used with a single control line to a subsurface safety valve. The operating piston is exposed to the flow tube between two blocks with near identical seals to make the piston insensitive to tubing pressure. A control system seal is carried by the piston in the upper block and a passage between the control system seal and the tubing pressure seal in the upper block communicates to a compressible fluid reservoir in the lower block that is also isolated from tubing pressure by a tubing pressure seal. Movement of the piston compresses the fluid in the reservoir. The reservoir can also include a spring to return the piston and the flow tube to a position to close the valve. A redundant system can be actuated if the primary system fails.
摘要:
A control system for a subsurface safety valve addresses normal open and closed operation and a failsafe operation if key system components fail. It features a single control line from the surface that splits at the subsurface safety valve and goes to one end of two discrete piston chambers that are aligned and isolated from tubing pressure. The piston in one chamber is larger than in the other and the pistons are connected for tandem movement. Each side of the unbalanced system's piston has a seal mounted to it and another for the rod attached to it that exits the chamber. A jumper line connects the chambers at a point between the seals in each chamber and features a large reservoir. The jumper line is filled with a compressible fluid. Fail safe closure of the valve occurs if any of the four seals fail.
摘要:
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.
摘要:
A control system for a subsurface safety valve features a control line from the surface leading to one side of an operating piston. The operating piston is exposed to tubing pressure and is in pressure balance from tubing pressure. The opposite end of the operating piston is exposed to a chamber in the housing of the subsurface safety valve and that chamber is open through a port to the surrounding annulus. The operating piston is coupled to the flow tube and a power spring so that pressure in the control line shifts the operating piston and the flow tube against the power spring to rotate the flapper open. Provisions for fail closed mode if certain seals fail are also made though a passage extending from between seals near the upper end of the operating piston to the chamber open to the annulus.