Chain drive system
AssigneeSchlumberger Technology Corporation
InventorsFalk W. Doering, Wade D. DuPree
Life of this patent
Estimating the term…
Abstract
A downhole tractor is provided that includes a motor, at least one rotatable screw powered by the motor, and a chain engageable with the at least one rotatable screw, whereby rotation of the at least one rotatable screw moves the chain.
Claims46
A downhole tractor assembly comprising a chain drive, the chain drive comprising:
- at least one rotatable screw;
- and
- a chain, the at least one rotatable screw being engageable with the chain such that rotation of the at least one rotatable screw causes linear movement of the chain.
A downhole tractor vehicle comprising:
- a motor;
- at least one rotatable screw powered by the motor;
- a flexible track engaged with the at least one rotatable screw, whereby rotation of the at least one rotatable screw causes movement of the track.
A downhole tractor comprising:
- a motor,
- at least one rotatable screw powered by the motor, and
- a chain engageable with the at least one rotatable screw, whereby rotation of the at least one rotatable screw moves the chain.
A method of conveying an item in an oil and gas well, comprising:
- providing a downhole tractor comprising a motor, at least one rotatable screw powered by the motor, and a flexible track, the at least one rotatable screw being engageable with the track such that rotation of the at least one rotatable screw causes linear movement of the track,
- connecting the item to the downhole tractor,
- engaging the track with a surface,
- activating the motor, and
- moving the downhole tractor along the surface.
A method of conveying an item, comprising:
- providing a vehicle including a motor, a first and a second chain, and a first, a second, a third and a fourth rotatable screw, each screw being powered by the motor, the first and second rotatable screws positioned in generally parallel relationship on opposite sides of the first chain and engageable with the first chain such that rotation of the first and second screws in opposite directions causes movement of the first chain, and the third and fourth rotatable screws positioned in generally parallel relationship on opposite sides of the second chain and engageable with the second chain such that rotation of the third and fourth screws in opposite directions causes movement of the second chain,
- connecting the item to the vehicle,
- engaging the first chain with a first surface,
- engaging the second chain with a second surface,
- activating the motor to rotate the first, second, third and fourth screws, and
- moving the vehicle along the first and second surfaces in a first direction.
A method of conveying an item in a borehole having an inner surface, comprising:
- providing a downhole tractor including a motor, a rotatable screw powered by the motor, and a flexible track, the screw being engageable with the track such that rotation of the screw causes movement of the track,
- connecting the item to the tractor,
- engaging the track with the surface,
- activating the motor to rotate the screw in a first direction, and
- moving the tractor along the surface in a first direction.
A method of converting rotary motion into linear motion in a downhole tractor comprising:
- providing at least one rotatable screw,
- providing a flexible track,
- engaging the at least one rotatable screw with the flexible track, and
- rotating the at least one rotatable screw so as to move the flexible track.
Dependencies are inferred from the claim text.