Releasing tool

Claim 1

A releasing tool having one end thereof being adapted to be releasably attached to a hook-up nipple having a bore therethrough of a gravel pack screen assembly while having the other end thereof adapted to be releasably attached to a tubing string, said releasing tool comprising: case means for releasably attaching said releasing tool to said tubing string, said case means including: adapter means having a bore therethrough for releasably attaching said releasing tool to said tubing string; ported case means having a bore therethrough, having a plurality of ports therein for communicating the bore of said ported case means with the exterior of said ported case means and having annular seal means disposed in the wall of the bore through said ported case means on opposite sides of said ports; and releasing body means having a bore therethrough and a plurality of apertures therein; releasing block means retained within the apertures in said releasing body means of said case means for releasably attaching said releasing tool to said hook-up nipple of said gravel pack screen assembly; releasing mandrel means slidably disposed within said case means for alternately allowing said releasing block means to engage and disengage an annual channel in said hook-up nipple of said gravel pack screen assembly when said releasing mandrel means is moved from a first position in said case means maintaining said releasing block means engaging said hook-up nipple to a second position in said case means allowing said releasing block means to disengage said hook-up nipple, said releasing mandrel means including: a cylindrical member slidably disposed within said case means, said cylindrical member having a bore therethrough, a first annular channel in the exterior surface thereof, and a second annular channel in the exterior surface thereof for receiving said releasing block means therein when said releasing mandrel means is in said second position allowing said releasing block means to disengage said hook-up nipple; shear pin means securing said ported case means to said releasing mandrel means thereby maintaining said releasing mandrel means in said first position in said case means; and snap ring means retained in an annular cavity formed when a portion of one end of said ported case means abuts a portion of one end of said releasing body means, said snap ring means engaging the first annular channel in said releasing mandrel means when said releasing mandrel means is in said second position thereby retaining said releasing mandrel means in said second position.