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.

Abstract: A drilling system utilizing a plurality of independent telemetry systems. The drilling system uses a drill collar as a pressure housing for downhole components of the system. One or more sensors are disposed within the pressure housing. These sensors can be MWD sensors, LWD sensors, or both MWD and LWD sensors. A plurality of independent borehole telemetry systems is used to telemeter sensor response data to the surface of the earth. Each sensor cooperates with a downhole component of at least one of the independent telemetry systems. The plurality of telemetry systems can be of the same type, such as a mud pulse systems. Alternately, the telemetry systems can be of different types including a mud pulse system and an electromagnetic system.

Abstract: A drilling system utilizing a plurality of independent telemetry systems. The drilling system uses a drill collar as a pressure housing for downhole components of the system. One or more sensors are disposed within the pressure housing. These sensors can be MWD sensors, LWD sensors, or both MWD and LWD sensors. A plurality of independent borehole telemetry systems is used to telemeter sensor response data to the surface of the earth. Each sensor cooperates with a downhole component of at least one of the independent telemetry systems. The plurality of telemetry systems can be of the same type, such as a mud pulse systems. Alternately, the telemetry systems can be of different types including a mud pulse system and an electromagnetic system.