Abstract: A subterranean tool that has a pressurized chamber when brought out of the hole after being actuated is depressurized by a tool that facilitates location of a technician at a distance when the gas is allowed to escape. Preferably, the tool features a hydraulic system with a device to build pressure at the technician end and a suitably long hydraulic line to the subterranean tool to connect to the venting tool that is independently secured to the subterranean tool to be depressurized. Raising the hydraulic pressure in the system extends a piston in the venting tool against a rupture disc to cause the disc to fail and the pressurized gas to escape. The vent tool is secured against longitudinal or relative rotational movement with respect to the subterranean tool. Variations including pneumatic or electrically or magnetically driven pistons, among other variants are also contemplated.

Abstract: A pressure pulse signal is processed and a valve is operated to allow tubing or annulus pressure to move a piston against an atmospheric or low pressure chamber. Movement of the piston triggers the release of the dogs that previously held two components together for a separation. Redundant release mechanisms that respond to discrete pressure pulse signals are provided for backup purposes.

Abstract: A pressure pulse signal is processed and a valve is operated to allow tubing or annulus pressure to move a piston against an atmospheric or low pressure chamber. Movement of the piston triggers the release of the dogs that previously held two components together for a separation. Redundant release mechanisms that respond to discrete pressure pulse signals are provided for backup purposes.