An ultra high pressure pump having a servo motor coupled to a piston having a head arranged within a cylinder to define a pumping chamber, whereby the servo motor rotation causes reciprocal displacement of the piston to pressurize fluid in the pumping chamber to pressures greater than 50,000 psi, the servo motor having a feedback loop coupled to a computer, the feedback loop including a pressure feedback signal to control the pump pressure in real time.

An actuator for use with a fluid transfer device is provided. The actuator includes a piston cylinder having a longitudinal axis and defining a piston chamber having both a head end and a longitudinally opposite base end. The actuator further includes a piston disposed within the piston chamber. The piston movable between a first piston position proximate the piston chamber head end and a second piston position proximate the piston chamber base end. The piston includes a piston head end having a first indexing mechanism, a first piston seal, and at least one first feed hole. The piston further includes a base end longitudinally opposite the head end having a second indexing mechanism, a guide tooth, a second piston seal, and at least one second feed hole. The piston defines a plurality of channels that extends from proximate the first piston seal to proximate the second piston seal.

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.

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.

Illustrative embodiments of pump systems and methods are disclosed. In at least one embodiment, an apparatus comprises a piston pump including a motor and a plunger, where the motor is configured to drive linear reciprocating motion of the plunger in response to being supplied with a flow of compressed fluid, a metering valve fluidly coupled to the motor, the metering valve being configured to control the flow of compressed fluid to the motor, a purge valve fluidly coupled between the metering valve and the motor, a linear encoder coupled to the piston pump, the linear encoder configured to generate sensor data indicative of a position of the plunger, and an electronic controller operatively coupled to the metering valve, the purge valve, and the linear encoder, where the electronic controller is configured to receive sensor data from the linear encoder and to control the metering valve and the purge valve.

A pump with a position indicator is disclosed. The pump includes a pump housing, wherein the pump housing includes a flexible bladder disposed therein; a first fluid zone, wherein the first fluid zone is operable to allow flow of a first fluid into and out of the first fluid zone; and a second fluid zone, wherein the second fluid zone is operable to allow flow of a second fluid into and out of the second fluid zone. The pump further includes a flexible position indicator disposed in the first fluid zone and in communication with the flexible bladder, wherein the flexible position indicator is operable to detect a linear position of the flexible bladder, and wherein the flexible bladder fluidly isolates the first fluid zone from the second fluid zone.