| Patent Number |
Title Of Patent |
Date Issued |
| 6089332 |
Steerable rotary drilling systems |
July 18, 2000 |
| A steerable rotary drilling system has a bottom hole assembly which includes, in addition to the drill bit, a modulated bias unit and a control unit, the bias unit comprising a number of hydraulic actuators around the periphery of the unit, each having a movable thrust member which i |
| 5959380 |
Prevention of particle accumulation between rotatable components of an electrical machine |
September 28, 1999 |
| An electrical machine, such as an electric motor, generator or torquer-generator, includes a relatively rotatable cylindrical armature and magnetic pole structure separated by an annular gap into which a surrounding fluid may flow during operation of the machine. In order to prevent |
| 5803185 |
Steerable rotary drilling systems and method of operating such systems |
September 8, 1998 |
| A steerable rotary drilling system has a bottom hole assembly which includes, in addition to the drill bit, a modulated bias unit and a control unit, the bias unit comprising a number of hydraulic actuators around the periphery of the unit, each having a movable thrust member which i |
| 5695015 |
System and method of controlling rotation of a downhole instrument package |
December 9, 1997 |
| 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 |
| 5685379 |
Method of operating a steerable rotary drilling system |
November 11, 1997 |
| A steerable rotary drilling system comprises a bottom hole assembly which includes, in addition to a drill bit, a modulated bias unit and a control unit including an instrument carrier which is rotatable relative to the bias unit. The bias unit comprises a number of hydraulic actuators s |
