A downhole-type system includes a rotatable shaft; a sensor that can sense an axial position of the shaft and generate a first signal corresponding to the axial position of the shaft; a controller coupled to the sensor, in which the controller can receive the first signal generated by the sensor, determine an amount of axial force to apply to the shaft to maintain a target axial position of the shaft, and transmit a second signal corresponding to the determined amount of axial force; and multiple magnetic thrust bearings coupled to the shaft and the controller, in which each magnetic thrust bearing can receive the second signal from the controller and modify a load, corresponding to the second signal, on the shaft to maintain the target axial position of the shaft.

A system to provide power to a downhole-type tool includes a downhole-type electric motor that can be positioned in a wellbore and a variable speed drive electrically connected to the electric motor, in which the downhole-type electric motor can operate at rotary speeds of at least 6,000 rotations per minute (rpm), the variable speed drive can control and supply power to the electric motor when the electric motor is positioned at a downhole location inside the wellbore, and the variable speed drive can be at a surface of the wellbore.

During rotation of a shaft of a downhole-type wellbore system, a first signal corresponding to an axial position of the rotating shaft is transmitted by a sensor. The shaft is axially levitated by a plurality of magnetic thrust bearings. A controller determines an amount of axial force to apply to the rotating shaft to maintain axial levitation of the rotating shaft based on the first signal. The controller transmits a second signal corresponding to the determined amount of axial force to the plurality of magnetic thrust bearings. The plurality of magnetic thrust bearings applies the amount of axial force on the rotating shaft to maintain the axial levitation of the rotating shaft based on the second signal.

During rotation of a shaft of a downhole-type wellbore system, a first signal corresponding to an axial position of the rotating shaft is transmitted by a sensor. The shaft is axially levitated by a plurality of magnetic thrust bearings. A controller determines an amount of axial force to apply to the rotating shaft to maintain axial levitation of the rotating shaft based on the first signal. The controller transmits a second signal corresponding to the determined amount of axial force to the plurality of magnetic thrust bearings. The plurality of magnetic thrust bearings applies the amount of axial force on the rotating shaft to maintain the axial levitation of the rotating shaft based on the second signal.

An oil well pumping unit. The pumping unit has a vertical support column residing adjacent a horizontal support base at a generally transverse orientation. The pumping unit has a standing sheave fixed proximate an upper end of the vertical support column, a carrier bar configured to be attached to a polished rod along the front face of the vertical support column, and a traveling sheave configured to move up and down along the vertical support column. A near-vertical actuator resides along the horizontal support base, and is connected to the traveling sheave. Cyclical movement of the linear actuator causes the traveling sheave to reciprocate up and down along the vertical support column such that upward movement of the traveling sheave produces a downstroke of the polished rod, while downward movement of the traveling sheave produces an upstroke of the polished rod. The linear actuator remains in tension at all times during movement of the polished rod.

An oil well pumping unit. The pumping unit has a vertical support column residing adjacent a horizontal support base at a generally transverse orientation. The pumping unit has a standing sheave fixed proximate an upper end of the vertical support column, a carrier bar configured to be attached to a polished rod along the front face of the vertical support column, and a traveling sheave configured to move up and down along the vertical support column. A near-vertical actuator resides along the horizontal support base, and is connected to the traveling sheave. Cyclical movement of the linear actuator causes the traveling sheave to reciprocate up and down along the vertical support column such that upward movement of the traveling sheave produces a downstroke of the polished rod, while downward movement of the traveling sheave produces an upstroke of the polished rod. The linear actuator remains in tension at all times during movement of the polished rod.

A measurement tool includes a rotor to rotate about a longitudinal axis, an axial gap generator having a stator assembly adjacent to the rotor, and a movable support structure to which the stator assembly is mounted. The axial gap generator generates a voltage signal as a function of a gap spacing between the stator assembly and the rotor, where the gap spacing is parallel to the longitudinal axis. The movable support structure moves the stator assembly parallel to the longitudinal axis based at least in part on a physical property of an environment about the movable support structure.

A wellbore pump includes a receptacle for a pump formed into a wellbore production tubing. A pump includes a seal engageable with an interior surface of the receptacle. The seal has a pump rod passing sealingly through the seal. The pump rod has a piston in sealing engagement with an interior of the tubing on each side of the seal. A power fluid line is in hydraulic connection to an interior of the production tubing above and below the seal. A well fluid inlet port is disposed between one of the pistons. A longitudinally spaced apart check valve is disposed in the wellbore production tubing above an upper one of the pistons.

Methods and systems are provided to adaptively control a hydraulic fluid supply to supply a driving fluid for applying a driving force on a piston in a gas compressor, the driving force being cyclically reversed between a first direction and a second direction to cause the piston to reciprocate in strokes. During a first stroke of the piston, a speed of the piston, a temperature of the driving fluid, and a load pressure applied to the piston is monitored. Reversal of the driving force after the first stroke is controlled based on the speed, load pressure, and temperature.

Methods and systems are provided to adaptively control a hydraulic fluid supply to supply a driving fluid for applying a driving force on a piston in a gas compressor, the driving force being cyclically reversed between a first direction and a second direction to cause the piston to reciprocate in strokes. During a first stroke of the piston, a speed of the piston, a temperature of the driving fluid, and a load pressure applied to the piston is monitored. Reversal of the driving force after the first stroke is controlled based on the speed, load pressure, and temperature.