Expandable mill and methods of use
AssigneeBaker Hughes Incorporated
InventorsGeorge N. Krieg, David Hebert
Life of this patent
Estimating the term…
Abstract
In some embodiments, apparatus useful for cleaning at least part of the interior surface of a generally cylindrically-shaped member disposed in a subterranean well includes a housing and a plurality of retractable mill blades supported on the housing and movable from an initial retracted position to an extended position and thereafter to a final retracted position.
Claims20
A drift sub equipped to be capable of cleaning at least part of the interior surface of a casing in a subterranean well prior to the insertion therein of completion hardware and/or accessories, the drift sub comprising:
- a tubular housing having an upper end, a lower end and a bore extending therebetween, said housing being deployable into and moveable within the casing;
- a plurality of mill blades supported on said housing and arranged in at least one row around the outer circumference of said housing, each said mill blade being movable between at least one retracted position and at least one extended position relative to the housing, said mill blades in said extended position extending radially outwardly beyond the outer diameter of said housing and capable of contacting the interior surface of the casing, and said mill blades in said retracted position being unable to contact the interior surface of the casing, wherein said mill blades are initially positioned in said retracted position upon deployment of said housing into the casing;
- an inner sleeve disposed within said bore of said housing and biasingly engaging each said mill blade, said inner sleeve being configured to be selectively movable axially relative to said housing only in the direction of said lower end thereof at least from a first position to a second position and therefrom to a third position, said inner sleeve in said first and third positions biasing said mill blades in said retracted position and said inner sleeve in said second position biasing said mill blades in said extended position;
- and
- an outer sleeve disposed within said bore radially outwardly relative to said inner sleeve and being releasably engaged therewith, said outer sleeve being configured to be selectively moveable axially relative to the housing only in the direction of said lower end thereof at least from a first position to a second position, wherein movement of said outer sleeve from its said first position to its said second position causes said inner sleeve to move from its said first position to its said second position,
- wherein said inner and outer sleeves are configured to be positioned in said respective first positions upon deployment of said housing into the casing and, thereafter, movement of said outer sleeve from its said first position to its said second position moves said inner sleeve from its said first position to its said second position, causing said mill blades to move into said extended position, and movement thereafter of said inner sleeve from its said second position to its said third position causes said mill blades to move into said retracted position, and
- whereby said inner sleeve in its third said position is unable to move back to its first or second said positions, securing said mill blades in said retracted position.
Apparatus useful to clean at least part of the interior surface of a generally cylindrically-shaped member in a subterranean well, the apparatus comprising:
- a housing having an upper end, a lower end and a bore extending therebetween, said housing being deployable into and moveable within the generally cylindrically-shaped member;
- a plurality of mill blades supported on said housing and arranged in at least one row around the outer circumference of said housing, each said mill blade being movable between at least one retracted position and at least one extended position relative to the housing, said mill blades in said extended position extending radially outwardly beyond the outer diameter of said housing and capable of contacting the interior surface of the generally cylindrically-shaped member, and said mill blades in said retracted position being unable to contact the interior surface of the generally cylindrically-shaped member, wherein said mill blades are initially positioned in said retracted position upon deployment of said housing into the generally cylindrically-shaped member;
- an inner sleeve disposed within said bore of said housing and biasingly engaging each said mill blade, said inner sleeve being configured to be selectively movable axially relative to said housing only in the direction of said lower end thereof at least from a first position to a second position and therefrom to a third position, said inner sleeve in said first and third positions biasing said mill blades in said retracted position and said inner sleeve in said second position biasing said mill blades in said extended position;
- an outer sleeve disposed within said bore radially outwardly relative to said inner sleeve and being releasably engaged therewith, said outer sleeve being configured to be selectively moveable axially relative to the housing only in the direction of said lower end thereof at least from a first position to a second position, wherein movement of said outer sleeve from its said first position to its said second position causes said inner sleeve to move from its said first position to its said second position;
- and
- first and second detachable seats releasably engaged with said outer and inner sleeves, respectively, said first detachable seat useful to catch a first activating member inserted into said bore of said housing and move said inner and outer sleeves from their said first to said second respective positions, and said second detachable seat useful to catch a second activating member inserted into said bore and move said inner sleeve from its said second to third position.
A method of cleaning debris from at least part of the interior surface of a generally cylindrically-shaped member in a subterranean well with the use of a housing having a plurality of spring-biased mill blades associated therewith, the mill blades arranged in at least one row around the outer circumference of the housing, each mill blade being movable from a retracted position to an extended position and therefrom to a retracted position relative to the housing, the mill blades in an extended position extend radially outwardly beyond the outer diameter of the housing and are capable of contacting the interior surface of the generally cylindrically-shaped member, and the mill blades in a retracted position are unable to contact the interior surface of the generally cylindrically-shaped member, the method comprising:
- positioning the mill blades in a retracted position;
- inserting the housing into the generally cylindrically-shaped member, the housing having an upper end, a lower end and a bore therethrough;
- moving the mill blades into an extended position;
- reciprocating the housing to allow the mill blades to clean the interior surface of at least a portion of the generally cylindrically-shaped member;
- moving the mill blades into a retracted position, wherein the mill blades are thereafter unable to move back into an extended position;
- and
- removing the housing from the generally cylindrically-shaped member.
Dependencies are inferred from the claim text.