Abstract: A hydraulic pumping system can include a hydraulic actuator with a magnet that displaces with a piston, and a sensor that continuously detects a position of the magnet. A ferromagnetic wall of the hydraulic actuator is positioned between the magnet and the sensor. A hydraulic pumping method can include incrementally lowering a lower stroke extent of a rod string reciprocation over multiple reciprocation cycles of the rod string, and automatically varying the lower stroke extent or an upper stroke extent of the rod string reciprocation, in response to a measured vibration. Another hydraulic pumping method can include solving a wave equation in the rod string, and automatically varying a reciprocation speed of the rod string in response to a change in work performed during reciprocation cycles of the hydraulic actuator or a change in detected force versus displacement in different reciprocation cycles of the hydraulic actuator.

Abstract: A hydraulic pumping system can include a hydraulic actuator with a magnet that displaces with a piston, and a sensor that continuously detects a position of the magnet. A ferromagnetic wall of the hydraulic actuator is positioned between the magnet and the sensor. A hydraulic pumping method can include incrementally lowering a lower stroke extent of a rod string reciprocation over multiple reciprocation cycles of the rod string, and automatically varying the lower stroke extent or an upper stroke extent of the rod string reciprocation, in response to a measured vibration. Another hydraulic pumping method can include solving a wave equation in the rod string, and automatically varying a reciprocation speed of the rod string in response to a change in work performed during reciprocation cycles of the hydraulic actuator or a change in detected force versus displacement in different reciprocation cycles of the hydraulic actuator.

Abstract: A hydraulic pumping method for use with a subterranean well can include mounting a hydraulic actuator above a wellhead, the hydraulic actuator and the wellhead being axially aligned with each other and inclined relative to vertical The hydraulic actuator can be unsupported by any substructure or guy wires after the mounting. A hydraulic pumping system for use with a subterranean well can include a hydraulic actuator including a piston that displaces in response to pressure in the actuator, a magnet that displaces with the piston, and a magnetic field sensor that detects a presence of the magnet. The hydraulic actuator may be mounted above a wellhead, with the hydraulic actuator and the wellhead being axially aligned with each other and inclined relative to vertical.

Abstract: A reservoir analysis method can include transmitting a signal from a downhole pump in a wellbore, receiving the signal at another wellbore, and determining a reservoir characteristic from the received signal. A reservoir analysis system can include a downhole pump positioned in a wellbore and a sensor positioned at another wellbore. The downhole pump selectively transmits a signal, and the sensor receives the signal. Another reservoir analysis method can include selectively changing a reciprocating displacement of a rod string connected to a downhole pump in a wellbore, transmitting a signal from the downhole pump in response to the changed reciprocating displacement, receiving the signal at another wellbore, and determining a reservoir characteristic from the received signal.

Abstract: A well pumping system can include an actuator that reciprocates a rod string, and a rod rotator including at least one helical profile and at least one engagement device. The rod string may rotate in response to longitudinal displacement of the rod string while the engagement device is engaged with the helical profile. A method of rotating a rod string in a well can include rotating a rod in a rotary direction, in response to displacement of the rod in a longitudinal direction, and preventing rotation of the rod in an opposite rotary direction, in response to displacement of the rod in an opposite longitudinal direction.

Abstract: A well pumping system can include an actuator that reciprocates a rod string, and a rod rotator including at least one helical profile and at least one engagement device. The rod string may rotate in response to longitudinal displacement of the rod string while the engagement device is engaged with the helical profile. A method of rotating a rod string in a well can include rotating a rod in a rotary direction, in response to displacement of the rod in a longitudinal direction, and preventing rotation of the rod in an opposite rotary direction, in response to displacement of the rod in an opposite longitudinal direction.

Abstract: A reservoir analysis method can include transmitting a signal from a downhole pump in a wellbore, receiving the signal at another wellbore, and determining a reservoir characteristic from the received signal. A reservoir analysis system can include a downhole pump positioned in a wellbore and a sensor positioned at another wellbore. The downhole pump selectively transmits a signal, and the sensor receives the signal. Another reservoir analysis method can include selectively changing a reciprocating displacement of a rod string connected to a downhole pump in a wellbore, transmitting a signal from the downhole pump in response to the changed reciprocating displacement, receiving the signal at another wellbore, and determining a reservoir characteristic from the received signal.

Abstract: A well pumping system can include an actuator that reciprocably displaces a rod string, a continuous position sensor that continuously detects a position of a member of the actuator, and a control system that modifies reciprocal displacement of the rod string by the actuator, in response to an output of the continuous position sensor. A well pumping method can include reciprocably displacing a rod string, continuously detecting a velocity profile with a continuous position sensor, and modifying the velocity profile while the rod string reciprocably displaces, in response to an output of the continuous position sensor.

Abstract: A well pumping system can include an actuator that reciprocably displaces a rod string, a flowmeter that measures flow of a fluid between a power source and the actuator, and a control system that modifies reciprocal displacement of the rod string by the actuator, in response to an output of the flowmeter. A well pumping method can include reciprocably displacing a rod string, continuously determining a velocity profile of the rod string, and modifying the velocity profile while the rod string reciprocably displaces, in response to an output of a flowmeter. Another well pumping method can include reciprocably displacing a rod string with an actuator, continuously determining displacement in response to an output of a flowmeter, and modifying reciprocating displacement of the rod string by the actuator, in response to the output of the flowmeter.

Abstract: A hydraulic pumping method for use with a subterranean well can include mounting a hydraulic actuator above a wellhead, the hydraulic actuator and the wellhead being axially aligned with each other and inclined relative to vertical The hydraulic actuator can be unsupported by any substructure or guy wires after the mounting. A hydraulic pumping system for use with a subterranean well can include a hydraulic actuator including a piston that displaces in response to pressure in the actuator, a magnet that displaces with the piston, and a magnetic field sensor that detects a presence of the magnet. The hydraulic actuator may be mounted above a wellhead, with the hydraulic actuator and the wellhead being axially aligned with each other and inclined relative to vertical.

Abstract: A hydraulic pumping system can include a hydraulic actuator with a magnet that displaces with a piston, and a sensor that continuously detects a position of the magnet. A ferromagnetic wall of the hydraulic actuator is positioned between the magnet and the sensor. A hydraulic pumping method can include incrementally lowering a lower stroke extent of a rod string reciprocation over multiple reciprocation cycles of the rod string, and automatically varying the lower stroke extent or an upper stroke extent of the rod string reciprocation, in response to a measured vibration. Another hydraulic pumping method can include solving a wave equation in the rod string, and automatically varying a reciprocation speed of the rod string in response to a change in work performed during reciprocation cycles of the hydraulic actuator or a change in detected force versus displacement in different reciprocation cycles of the hydraulic actuator.

Abstract: An artificial lift system for a well having a wellhead reciprocates a rod string with an uphole pump unit at the wellhead to operate a downhole pump unit in the well and lift fluid in the well. A rod segment coupled to the rod string at the wellhead has first opposing surfaces facing in first opposing directions. Opposing catchers are movable laterally relative to the rod segment at the wellhead. Each of the catchers has a face with second opposing surfaces facing in second opposing directions opposite to the first opposing directions. The catchers moved in a first condition have the second opposing surfaces disengaged from the first opposing surfaces of the rod segment, but the catchers moved in a second condition have the second opposing surfaces engaged with the segment's first opposing surfaces to hold the rod string in place.