05293940 is referenced by 65 patents and cites 13 patents.

An automatic tubing release mechanism is adapted to be disposed in a wellbore between a tubing, on one end, and a perforating gun, on the other end. The release mechanism includes a frangible breakup tube, firing head positioned above the breakup tube, and the perforating gun positioned below the breakup tube when the release mechanism is disposed in the wellbore. A detonating cord is interconnected between the firing head and the perforating gun via the breakup tube. When the firing head detonates the perforating gun, the breakup tube shatters. When the breakup tube shatters: in accordance with one embodiment, a release piston, previously resting on the breakup tube, moves downwardly in response to hydrostatic pressure of wellbore fluid and releases a collet arm which rests against a threaded connection of a housing, the release of the collet arm disconnecting the perforating gun from the tubing, the perforating gun falling to a bottom of the wellbore; or, in accordance with another embodiment, wellbore fluid at hydrostatic pressure enters a plurality of fluid ports and exerts a pressure on an underside of a release piston causing the piston to move upwardly thereby releasing a collet arm which rests against a threaded connection of a housing, the release of the collet arm disconnecting the perforating gun from the tubing, the perforating gun falling to a bottom of the wellbore.

Title
Automatic tubing release
Application Number
858400
Publication Number
5293940
Application Date
March 16, 1993
Publication Date
March 15, 1994
Inventor
Klaus B Huber
Sugar Land
TX, US
Antoni K L Miszewski
Missouri City
TX, US
Joe C Hromas
Sugar Land
TX, US
Agent
John H Bouchard
Henry N Garrana
Assignee
Schlumberger Technology Corporation
TX, US
IPC
E21B 43/116
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