Abstract: A system and method for determining drilling parameters based on hydraulic pressure associated with a directional drilling system are disclosed. A drilling parameter associated with a directional drilling system may be determined by measuring hydraulic pressure associated with the directional drilling system during drilling of a wellbore, detecting a change in the hydraulic pressure, and determining a drilling parameter based on the detected change in hydraulic pressure.

Abstract: Systems and methods of downhole power generation are disclosed, which provide for the generation of electrical power in a downhole environment by the use of an electrical generator coupled to a hydraulic circuit that receives energy from a source in the downhole environment. The hydraulic circuit can receive energy from flowing drilling fluid and/or from kinetic energy of one or more portions of the drill string. A direct or indirect coupling can be used to transfer energy from the downhole environment to a pump in the hydraulic circuit, which can act as a hydraulic flow source, providing flow through a flow regulation device or control circuit. The hydraulic fluid under such control can then be used to turn a hydraulic motor, which is used to turn an electric generator for the generation of electricity for downhole tools such as logging tools, related telemetry, and the like.

Abstract: A disclosed example embodiment of a constant velocity device positionable in a well bore includes a continuously-variable transmission, including an input race coupled to a rotational power input shaft, an output race, and a plurality of transmission elements disposed between the input race and the output race in a planetary formation. The transmission elements are configured to transmit rotational power from the input race to the output race. The constant velocity device also includes a weighted rotor assembly coupled at a first end to the output race. The weighted rotor assembly includes at least two weighted lever arms rotatable about a central axis of a power output shaft coupled to a second end of the weighted lever arms.

Abstract: The subject matter of this specification can be embodied in, among other things, a tool string positionable in a wellbore that includes a spur gear driven by a source of input rotation, a planetary gearbox having an attachment structure to connect to the spur gear. The gearbox includes a central sun gear, a collection of planet gears disposed in a planet gear carrier disposed around the central sun gear, and a ring gear disposed around the planet gears and planet gear carrier. The attachment structure drives a hydraulic pump or electrical generator at a rotational speed different than a rotational speed of the source of input rotation.

Abstract: A rotary steerable drilling system includes a housing, a drive shaft passing through the housing, a shaft/housing locking mechanism disposed to selectively engage the drive shaft and the housing, and an anti-rotation mechanism disposed to engage a wellbore wall. Shaft/housing locking mechanism includes a first configuration in which rotation of the drive shaft is independent of the housing, and a second configuration in which rotation of the drive shaft causes rotation of the housing. Anti-rotation mechanism includes a first configuration in which the anti-rotation mechanism extends radially relative to the drive shaft, and a second configuration in which the anti-rotation mechanism retracts from engagement with the wellbore wall. A timing mechanism may be employed to transition the anti-rotation mechanism from the first configuration to the second configuration before the shaft/housing locking mechanism transitions from the first configuration to the second configuration.