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AssigneeCamco Drilling Group Limited of Hycalog
InventorsJohn D. Barr, William C. Motion, Michael K. Russell
Estimating the term…
A system for controlling the rotation of a roll stabilizable control unit in a steerable rotary drilling assembly comprises an instrument carrier rotatably mounted on a support connected to the drill string. A first rotatable impeller is mounted for rotation by a flow of drilling fluid over the impeller and is coupled to the instrument carrier so as to transmit a torque to it. Sensors carried by the instrument carrier sense the rotational orientation of the instrument carrier and produce a control signal indicative of its rotational orientation, and the torque applied to the instrument carrier by the impeller is controlled, at least partly in response to said signal, so that the instrument carrier can, for example, be roll stabilized if required. A second rotatable impeller is coupled to the instrument carrier for transmitting to it a second torque, which may also be controlled, in the opposite direction to the torque transmitted by the first impeller. The provision of two opposed impellers allows the rotation of the control unit to be controlled over a greater range than is possible with a single impeller.
A system for controlling the rotation of a downhole instrumentation package with respect to a drill string, comprising:
A method of controlling the rotation of a downhole instrumentation package, comprising the steps of:
A method of controlling the rotation of a downhole instrumentation package, comprising the steps of:
A system for transmitting information from a downhole assembly, comprising:
Dependencies are inferred from the claim text.