Abstract: A fully rotating bias unit for directional drilling rotates at bit speed while providing proportional control of directional response and steering force. The unit also provides added reliability by having increased redundancy (multiple independently controlled actuators). The unit disposed on a drillstring transfers rotation to a drill bit and has a bore communicating fluid from the drillstring to the drill bit. Directors are disposed on the unit to rotate with it. Each of the directors is independently movable between extended and retracted conditions relative to the unit's housing. Actuators of the unit are in fluid communication between the bore and the borehole or some other low pressure. Each actuator is independently operable to direct communicated fluid from the bore to extend a respective one of the directors toward the extended condition.

Abstract: A fully rotating bias unit for directional drilling rotates at bit speed while providing proportional control of directional response and steering force. The unit also provides added reliability by having increased redundancy (multiple independently controlled actuators). The unit disposed on a drillstring transfers rotation to a drill bit and has a bore communicating fluid from the drillstring to the drill bit. Directors are disposed on the unit to rotate with it. Each of the directors is independently movable between extended and retracted conditions relative to the unit's housing. Actuators of the unit are in fluid communication between the bore and the borehole or some other low pressure. Each actuator is independently operable to direct communicated fluid from the bore to extend a respective one of the directors toward the extended condition.

Abstract: A fully rotating bias unit for directional drilling rotates at bit speed while providing proportional control of directional response and steering force. The unit also provides added reliability by having increased redundancy (multiple independently controlled actuators). The unit disposed on a drillstring transfers rotation to a drill bit and has a bore communicating fluid from the drillstring to the drill bit. Directors are disposed on the unit to rotate with it. Each of the directors is independently movable between extended and retracted conditions relative to the unit's housing. Actuators of the unit are in fluid communication between the bore and the borehole or some other low pressure. Each actuator is independently operable to direct communicated fluid from the bore to extend a respective one of the directors toward the extended condition.

Abstract: A drilling assembly disposed on a drillstring deviates a borehole (i.e., changes the trajectory of the borehole) advanced by a drill bit. A housing disposed on the drillstring transfers first rotation to the drill bit, and one or more directors are disposed on the housing to rotate therewith. Each of the directors is independently movable between an extended condition and a retracted condition relative to the housing. An actuator is disposed on the assembly and is operable provide a second rotation relative to the first rotation. An internal component is disposed in the housing and is rotatable by the second rotation of the actuator to have first and second conditions relative to each of the one or more directors rotating with the first rotation of the housing. The internal component in the first condition extends a given one of the one or more directors toward the extended condition.

Abstract: A drilling assembly disposed on a drillstring deviates a borehole (i.e., changes the trajectory of the borehole) advanced by a drill bit. A housing disposed on the drillstring transfers first rotation to the drill bit, and one or more directors are disposed on the housing to rotate therewith. Each of the directors is independently movable between an extended condition and a retracted condition relative to the housing. An actuator is disposed on the assembly and is operable provide a second rotation relative to the first rotation. An internal component is disposed in the housing and is rotatable by the second rotation of the actuator to have first and second conditions relative to each of the one or more directors rotating with the first rotation of the housing. The internal component in the first condition extends a given one of the one or more directors toward the extended condition.

Abstract: A fully rotating bias unit for directional drilling rotates at bit speed while providing proportional control of directional response and steering force. The unit also provides added reliability by having increased redundancy (multiple independently controlled actuators). The unit disposed on a drillstring transfers rotation to a drill bit and has a bore communicating fluid from the drillstring to the drill bit. Directors are disposed on the unit to rotate with it. Each of the directors is independently movable between extended and retracted conditions relative to the unit's housing. Actuators of the unit are in fluid communication between the bore and the borehole or some other low pressure. Each actuator is independently operable to direct communicated fluid from the bore to extend a respective one of the directors toward the extended condition.

Abstract: A drilling assembly disposed on a drillstring can deviate a borehole advanced by a drill bit. A housing coupled between the drillstring and the bit transfers rotation of the drillstring to the bit. A mandrel in the housing's axial bore has a least one inclined surface on at least one side. The mandrel is subject to pressure in the housing and can be displaced longitudinally. A biasing element biases the mandrel toward one position. At least one piston disposed on the housing's side can be moved by the at least one inclined surface and can be displaced transversely in response to the longitudinal displacement of the mandrel. To vary the transverse displacement of the piston and change a trajectory of the borehole, changes to the differential pressure across the mandrel longitudinally displaces the mandrel and moves the piston.

Abstract: A downhole assembly for directionally drilling a borehole has a motor, a transmission, and a steering mechanism. The motor has a rotor driven in a stator by flow of drilling fluid therebetween. The transmission operatively couples the rotor to a drill bit for drilling the borehole. A flow control controls the flow of drilling fluid through an internal passage of the rotor. The flow control can thereby vary the drive of the rotor in a bit speed effect that preferentially cuts the wall of the borehole to achieve directional drilling. The flow control can also thereby create a differential pressure displacing the rotor along a longitudinal axis of the motor in a thrust effect. The steering mechanism responds to the displacement of the rotor and deviates a direction of the drill bit from the longitudinal axis of the motor to further achieve directional drilling. The bit speed effect, the rotor displacement, and the deviation are preferentially coordinated to coincide or at least operate together.