US 5,881,816 A · Packer mill

Abstract

A packer mill system for milling a packer in a wellbore has been invented which has, in certain aspects, a bushing with a hollow generally cylindrically shaped bushing body with a bottom, a top, a bushing bore extending therethrough from top to bottom, and at least one key on an interior surface thereof, the at least one key projecting inwardly into the bushing bore, a mandrel initially disposable within the bushing, the mandrel having a hollow generally cylindrically shaped mandrel body with a top, a bottom, a mandrel bore extending therethrough from top to bottom, and a slot system formed in an exterior surface of the mandrel body, the at least one key disposed for movement through the slot system, engagement apparatus connected to the bottom of the mandrel body for engaging the packer, milling apparatus connected to the bottom of the bushing body and disposed for movement therethrough of the engagement apparatus, the slot system having a series of one or more interconnected slots through which the at least one key is movable, the series of interconnected slot(s) including one or more exits at the top and at the bottom for movement of the at least one key out from the slot system thereby freeing the bushing from the mandrel. In certain aspects torsion or torque is applied only by the slot system and only in a single direction so that, when using a downhole motor, a rotary shoe or other mill can be replaced or redressed and then reinserted into the wellbore through the slot system to continue milling.

Claims22

Dependent claims

A packer mill system for removing a packer from a wellbore, the packer mill system comprising

a bushing having a hollow generally cylindrically shaped bushing body with a bottom, a top, a bushing bore extending therethrough from top to bottom, and at least one key on an interior surface thereof, the at least one key projecting inwardly into the bushing bore, the bushing rotatable in a first direction and in a second direction opposite the first direction,
a mandrel initially disposable within the bushing, the mandrel having a hollow generally cylindrically shaped mandrel body with a top, a bottom, a mandrel bore extending therethrough from top to bottom, and a slot system formed in an exterior surface of the mandrel body,
the at least one key disposed for movement in and through the slot system,
engagement apparatus connected to the bottom of the mandrel body for engaging the packer,
milling apparatus connected to the bottom of the bushing body and disposed for movement therethrough of the engagement apparatus,
the slot system having a top and a bottom and a series of interconnected slots through which the at least one key is movable, the series of interconnected slots including exit means for movement of the at least one key out from the slot system thereby freeing the bushing from the mandrel,
a coiled tubing string extending into the wellbore,
a downhole motor interconnected between the coil tubing and the bushing for providing rotation in the first direction, and
the bushing configured and positioned so that pulling upon the bushing moves the at least one key to contact the slot system thereby rotating the bushing in the second direction,
wherein the milling apparatus is rotated by the downhole motor.

7 more elements

A method for retrieving a packer secured in a wellbore, the method comprising

introducing a packer mill system into the wellbore, the packer mill system comprising a bushing having a hollow generally cylindrically shaped bushing body with a bottom, a top, a bushing bore extending therethrough from top to bottom, and at least one key on an interior surface thereof, the at least one key projecting inwardly into the bushing bore, a mandrel initially disposable within the bushing, the mandrel having a hollow generally cylindrically shaped mandrel body with a top, a bottom, a mandrel bore extending therethrough from top to bottom, and a slot system formed in an exterior surface of the mandrel body, the at least one key disposed for movement in and through the slot system, engagement apparatus connected to the bottom of the mandrel body for engaging the packer, milling apparatus connected to the bottom of the bushing body and disposed for movement therethrough of the engagement apparatus, and the slot system having a top and a bottom and a series of interconnected slots through which the at least one key is movable, the series of interconnected slots including exit means for movement of the at least one key out from the slot system thereby freeing the bushing from the mandrel, the bushing selectively releasably connected to the mandrel, a coiled tubing string extending into the wellbore, a downhole motor interconnected between the coil tubing and the bushing for providing rotation in the first direction, the bushing configured and positioned so that pulling up on the bushing moves the at least one key to contact the slot system thereby rotating the bushing in the second direction, and wherein the milling apparatus is rotated by the downhole motor, releasing the mandrel from the bushing,
engaging the packer with the engagement apparatus,
releasing the bushing from the mandrel,
moving the at least one key through the slot system,
moving the milling apparatus into contact with the packer,
rotating the bushing with the downhole motor to rotate the milling apparatus in the first direction to mill the packer,
moving the bushing and the milling apparatus up away from the packer,
engaging the at least one key in the slot system thereby providing rotation of the bushing in the second direction, and
pulling up on the packer with the packer mill system to remove the packer from the wellbore.

6 more elements

Dependencies are inferred from the claim text.

Packer mill

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Packer mill

Life of this patent

Abstract

Claims22