Torque control device for a downhole drilling assembly
First Claim
1. A torque control device for a downhole drilling assembly, the downhole drilling assembly comprising a drill bit and connected componentry which are adapted to rotate during drilling, the torque control device being adapted for connection to the drill bit, the torque control device including an outer sleeve and an inner shaft, the outer sleeve and the inner shaft being respective parts of the connected componentry which are adapted to rotate during drilling, the outer sleeve being movable longitudinally relative to the inner shaft, the torque control device having a cylinder, a piston located within the cylinder, and a controller to adjust the volume of the cylinder, the volume of the cylinder being adjustable whilst the outer sleeve and the inner shaft are rotating.
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Accused Products
Abstract
This invention relates to a torque control device for a downhole drilling assembly. The torque control device is adapted for connection to a drill bit, and has an outer sleeve and an inner shaft, the outer sleeve being movable longitudinally relative to the inner shaft. The torque control device also has a cylinder, a piston located within the cylinder, and a controller to control the volume of the cylinder. Changing the volume of the cylinder causes relative longitudinal movement between the outer sleeve and the inner shaft. The controller can receive inputs from a torque sensor and/or an accelerometer in order to determine if a threshold torque has been exceeded. Alternatively the controller can comprise a rotary valve which automatically responds to torque in the assembly.
51 Citations
21 Claims
- 1. A torque control device for a downhole drilling assembly, the downhole drilling assembly comprising a drill bit and connected componentry which are adapted to rotate during drilling, the torque control device being adapted for connection to the drill bit, the torque control device including an outer sleeve and an inner shaft, the outer sleeve and the inner shaft being respective parts of the connected componentry which are adapted to rotate during drilling, the outer sleeve being movable longitudinally relative to the inner shaft, the torque control device having a cylinder, a piston located within the cylinder, and a controller to adjust the volume of the cylinder, the volume of the cylinder being adjustable whilst the outer sleeve and the inner shaft are rotating.
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20. A torque control device for a downhole drilling assembly, the torque control device being adapted for connection to a drill bit, the torque control device including an outer sleeve and an inner shaft, the outer sleeve being movable longitudinally relative to the inner shaft;
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the torque control device having a cylinder, a piston located within the cylinder, and a controller to control the volume of the cylinder, the cylinder being filled with drilling fluid in use; the torque control device having a through-bore for carrying drilling fluid to the drill bit, a fluid entry port between the through-bore and the cylinder, and an actuating valve controlling the flow of drilling fluid through the fluid entry port, the actuating valve being located within the piston.
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21. A torque control device for a downhole drilling assembly, the torque control device being adapted for connection to a drill bit, the torque control device including an outer sleeve and an inner shaft, the outer sleeve being movable longitudinally relative to the inner shaft;
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the torque control device having a cylinder, a piston located within the cylinder, and a controller to control the volume of the cylinder, the cylinder being filled with drilling fluid in use; the torque control device having a through-bore for carrying drilling fluid to the drill bit, a fluid entry port between the through-bore and the cylinder, an actuating valve controlling the flow of drilling fluid through the fluid entry port, and an exhaust port permitting the flow of drilling fluid out of the cylinder, the exhaust port being permanently open, the exhaust port having a smaller cross-sectional area than the fluid entry port.
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Specification