Hydraulic cutting overshot
OwnerCharles D. Hailey, Wayne M. Biartinventors
Life of this patent
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Abstract
An overshot cutter for suspension from coiled tubing that includes an elongate housing which includes a drive piston at the upper end with adjustable axial passage, an inner barrel there-below, and a cutter piston extending a collet cutter next below and finally a restrictor block; whereby the housing lower end is positioned down over a fish for hydraulic release of the drive piston to drive the inner barrel and cutter piston downward thereby to close the collet cutter within the restrictor block to cut the tubing below the fish.
Claims9
An overshot cutter for removing a fish from a wellbore, comprising:
- an elongate housing having upper and lower ends;
- means for suspending said housing in said wellbore with the lower end enveloping said fish;
- a drive piston retained in said housing upper end by means of a shear pin;
- a cutter piston slidably retained in said housing adjacent said lower end, said cutter piston extending a collet cutter therebelow;
- a restrictor block defining a reducing orifice proximate the lower end of said housing;
- and
- hydraulic means for shearing said drive piston shear pin and forcing said drive piston down to force said cutter piston down around said fish while the restrictor block closes the collet cutter to separate the fish for retention within the cutter piston for subsequent removal.
An overshot cutter for removing a fish from a wellbore comprising:
- a cylindrical housing having upper and lower ends;
- means for suspending said cylindrical housing in said wellbore with the lower end over said fish;
- a drive piston slidable in said cylindrical housing and disposed near the upper end of said housing;
- a shear pin locking said drive piston in said housing upper end;
- an inner barrel slidable within said housing below said drive piston;
- a cutter piston slidable in said housing below said inner barrel and extending a collet cutter below said cutter piston;
- a restrictor block secured in said housing below said cutter piston;
- and
- means for hydraulically forcing said drive piston down shearing the shear pin and striking the inner barrel and cutter piston in succession thereby to drive the collet cutter through the restrictor block to effect cutting separation of the fish.
Dependencies are inferred from the claim text.