Annular shaped power charge for subsurface well devices
AssigneeBaker Hughes Incorporated
InventorBrett W. Bouldin
Life of this patent
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Abstract
An annular shaped gas generating power charge is shown of the type which can be used in a downhole tool in a well. The charge is provided in the form of a longitudinal strip of solid propellant having a length and a width, a leading end which defines a burn area, a trailing end and opposing side edges. The strip is helically wrapped in at least one spiral turn about a central axis so that the opposing edges of the strip abut one another to form an annular shape. The annular shape provides a controlled gas generation rate and can be installed in the setting chamber of a downhole tool to provide a controlled setting action of the elastomeric components of the downhole tool.
Claims7
An annular shaped gas generating power charge of the type adapted to be used in a downhole tool in a subterranean well, the power charge comprising:
- a longitudinal strip of propellant having a length and a width less than the length, a leading end which defines a burn area, a trailing end and opposing non-combustible side edges, the strip being helically wrapped in a plurality of spiral turns occurring in a single plane about a central axis, whereby opposing edges of the strip abut one another to form a right circular cylinder.
In a downhole tool of the type used in a subterranean well having a tubular conduit of a given length extending downwardly from the well surface into contact with well fluids, at least a portion of the length of the tubular conduit being surrounded by an outer tubular member, the improvement comprising:
- an annular shaped gas generating power charge located in an annular space created between the tubular conduit and the outer tubular member, the power charge being comprised of a longitudinal strip of propellant having a length and a width less than the length, a leading end which defines a burn area, a trailing end, and opposing non-combustible side edges, the strip being helically wrapped about the tubular conduit in a plurality of spiral turns about a central axis, whereby opposing edges of the strip abut one another to form a cylindrical shape between the tubular conduit and the outer tubular member;
- and
- setting means responsive to ignition of the power charge for moving the downhole tool from a first position to a second position.
A downhole tool adapted for use in a subterranean well having an imperforate tubular conduit extending from the well surface downwardly to an actuating section, the downhole tool comprising:
- an inner tubular member having an imperforate length and being adapted to be made up in the imperforate tubular conduit extending from the well surface;
- an outer tubular member surrounding at least a portion of the inner tubular member and spaced-apart therefrom to define an annular space within the well tool;
- an annular shaped gas generating power charge located in the annular space, the power charge being comprised of a longitudinal strip of propellant having a length and a width less than the length, a leading end which defines a burn area, a trailing end, and opposing non-combustible side edges, the strip being helically wrapped about the inner tubular member in a plurality of spiral turns about a central axis, whereby opposing edges of the strip abut one another to form a cylindrical shape within the annular space;
- packing means surrounding a portion of the imperforate tubular conduit for forming a seal with the surrounding well bore;
- and
- setting means responsive to ignition of the power charge for moving the packing means into sealing engagement with the surrounding well bore.
Dependencies are inferred from the claim text.