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Cutting Knife Retraction Apparatus for Section Mill Cutting

IP.com Disclosure Number: IPCOM000240323D
Publication Date: 2015-Jan-22
Document File: 6 page(s) / 1M

Publishing Venue

The IP.com Prior Art Database

Abstract

When section milling in the upward direction a knife retraction device is needed to pull the cutting knives back inside the internal diameter of the casing that is being milled, so that the section mill can be pulled thru the casing and from the well bore at the completion of milling. Without the retraction device the blades may become lodged below the end of the casing string preventing the removal of the section mill. The device could also be used when milling downwards as well. At the end of milling down the blades would retract and would allow the tool to go further down inside the casing if needed. The retraction device would be added to the knife blades by mechanical means, welding or made integral to the material when the knife is machined. The device is shaped as a protruding lug such that when milling is stopped the internal spring inside the section mill forces the mandrel to move in contact with the retraction device forcing the knifes to pivot inward , so they are nesting inside the section mill body.

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Cutting Knife Retraction Apparatus for Section Mill Cutting

When section milling in the upward direction a knife retraction device is needed to pull the cutting knives back inside the internal diameter of the casing that is being milled, so that the section mill can be pulled thru the casing and from the well bore at the completion of milling.  Without the retraction device the blades may become lodged below the end of the casing string preventing the removal of the section mill.  The device could also be used when milling downwards as well.  At the end of milling down the blades would retract and would allow the tool to go further down inside the casing if needed.

The retraction device would be added to the knife blades by mechanical means, welding or made integral to the material when the knife is machined.  The device is shaped as a protruding lug such that when milling is stopped the internal spring inside the section mill forces the mandrel to move in contact with the retraction device forcing the knifes to pivot inward , so they are nesting inside the section mill body.