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US 8,783,354 B2Granted
Apparatus and method for adjusting spring preload in a downhole tool
AssigneeNational Oilwell Varco, L.P.
InventorsMark Sheehan, Jonathan Prill, Jeffery Clausen
Life of this patent
Estimating the term…
Abstract
Apparatus and method for adjusting spring preloading in a downhole tool. In an apparatus, a mechanism includes a nut and a piston. The nut is configured to axially compress a spring in the downhole tool. The piston is coupled to the nut. Extension of the piston causes the nut to rotate and compress the spring. The nut is configured to maintain compression of the spring after the piston retracts.
Claims32
Apparatus for adjusting preloading in a downhole tool, the apparatus comprising:
- a nut configured to axially compress a spring in the downhole tool;
- a piston coupled to the nut, wherein extension of the piston causes the nut to rotate and compress the spring, and
- the nut is configured to maintain compression of the spring after the piston retracts;
- a tubular shuttle disposed between the piston and the nut, and
- a retraction spring disposed between the nut and the shuttle, the spring configured to retract the shuttle and the piston toward an initial position.
2 more elements
A method for adjusting preloading of a spring in a downhole tool, comprising:
- applying hydraulic pressure from outside the downhole tool to a piston disposed within the tool;
- rotating the piston along a helical path along the longitudinal axis of the tool responsive to the applied hydraulic pressure;
- extending a compression member coupled to the piston responsive to the rotation of the piston;
- compressing the spring via the extension of the compression member;
- discontinuing application of hydraulic pressure to the piston;
- retracting the piston along the helical path;
- and
- retainin the compression member in an extended position after he piston is retracted.
5 more elements
A downhole tool for use in a borehole, comprising:
- a spring disposed about a longitudinal axis of the tool;
- a spring adjustment mechanism longitudinally coaxial with the spring, the spring adjustment mechanism comprising:
- a hydraulically driven piston;
- a compression member configured to retainably compress the spring responsive to rotation of the piston;
- and
- a tubular sleeve, wherein the piston is disposed about one end of the sleeve and the compression member is disposed about another end of the sleeve;
- and
- a cylindrical outer case disposed about the spring and the spring adjustment mechanism, the case comprising a first fluid port configured to provide pressurized fluid to the spring adjustment mechanism.
5 more elements
A downhole tool for use in a borehole, comprising:
- a spring disposed about a longitudinal axis of the tool;
- a spring adjustment mechanism longitudinally coaxial with the spring, the spring adjustment mechanism comprising:
- a hydraulically driven piston;
- a compression member configured to retainably compress the spring responsive to rotation of the piston;
- and
- a tubular shuttle disposed between the piston and the compression member, wherein the shuttle is configured to unidirectionally transfer piston rotation to the compression member, the shuttle comprising:
- longitudinal teeth at one end configured to engage matching longitudinal teeth of the piston, and
- splines at another end, the splines configured to couple to splines of the compression member;
- and
- a cylindrical outer case disposed about the spring and the spring adjustment mechanism, the case comprising a first fluid port configured to provide pressurized fluid to the spring adjustment mechanism.
7 more elements
A downhole tool for use in a borehole, comprising:
- a spring disposed about a longitudinal axis of the tool;
- a spring adjustment mechanism longitudinally coaxial with the spring, the spring adjustment mechanism comprising:
- a hydraulically driven piston;
- and
- a compression member configured to retainably compress the spring responsive to rotation of the piston;
- a cylindrical outer case disposed about the spring and the spring adjustment mechanism, the case comprising a first fluid port configured to provide pressurized fluid to the spring adjustment mechanism;
- and
- a second fluid port configured to provide fluid to the spring adjustment mechanism, wherein the pressure of the fluid returns the piston toward an initial position when hydraulic pressure at the first port is discontinued.
5 more elements
Dependencies are inferred from the claim text.