Apparatus for releasing a perforation gun

摘要

An improved apparatus for releasing a perforation gun from a tubing string in a well casing is disclosed. The explosion of a detonator that fires the perforation gun opens a previously sealed passageway through a wall of the apparatus of the invention. The passageway transmits bottom hole well pressure to a piston that actuates means for releasing the perforation gun. A secondary release sleeve is also provided to mechanically release the perforation gun when the piston fails to function properly. In an alternate embodiment of the apparatus of the invention, the perforation gun is released when the explosion of the detonator breaks a frangible rod that previously held one or more retaining balls within a recess in a wall of the perforation gun assembly.