Lock Out Tool
Lock Out Tool
The Lock-Out Tool is a mechanical and hydraulic device. It provides a means to permanently lock open a rod-piston tubing-retrievable safety valve (TRSV) when operating conditions dictate the necessity. The tool is installed and retrieved by using standard wireline methods. The lock-out procedure requires only a single wireline trip. The tool locates in the first matching nipple profile, which is in the top sub of the TRSV. The lock-out tool shifts the flow tube to the open position and raises a dimple on the top sub extension to lock the TRSV permanently open. This lock-out does not provide control-line communication. A communication tool must be run after the valve is locked open to establish control-line communication for a wireline valve. The TRSV control line can then be used to operate the wireline valve.
The lock-out tool is run and locates in the first matching nipple profile which is in the top sub of the TRSV. Downward jarring sets the locating keys of the lock-out tool. Pressure is then applied down the tubing string, shearing the shear screws, and allowing the shifting lugs to engage the flow tube of the TRSV. Further pressuring moves the flow tube downward. When the TRSV is in the full-open position, a built-in bypass valve in the lock-out tool opens and pressure above the TRSV starts to drop to give an indication on the surface that the TRSV is open. Continuously pumping down the tubing is not required due to a ratchet mechanism in the lock-out tool that maintains the TRSV in the open position. Downward jarring shears the shear screws and releases the core rod of the lock-out tool. Further jarring drives the extender button out and deforms the top sub extension. The dimple in the top sub extension above the opening prong permanently holds the TRSV in the open position. The lock-out tool is then retrieved.