An axial piston pump controller for an axial piston pump having a fixed valve plate and a variable displacement is provided. The axial piston pump controller is configured to determine a displacement of the axial piston pump, and to calculate a pump displacement control current to be supplied to the axial piston pump to control the displacement of the axial piston pump. Calculating the pump displacement control current comprises calculating a nominal value for the pump displacement control current based on a rotational speed of the axial piston pump, calculating a pump stiffness adjustment factor based on a pump stiffness control map having as inputs: an output pressure of the axial piston pump; and the estimated pump displacement, and calculating the pump displacement control current to be supplied to the axial piston pump based on the nominal value and the pump stiffness adjustment factor. The controller is further configured to output an instruction to output the calculated pump displacement control current to the axial piston pump in order to control the displacement of the axial piston pump.

A compressor includes a cylinder block having a first bore and a cylinder head overlapping the cylinder block. The cylinder head has a second bore aligned with the first bore. The second bore is separated into a plurality of distinct regions including a suction region and an economizer region. A plurality of valves includes a suction valve selectively operable to fluidly couple the suction region and the first bore, and an economizer valve selectively operable to fluidly couple the economizer region and the first bore.

The present invention refers to a method and system for reducing noise and positioning of piston (15) in starting failure of engine (20) configured to significantly reduce the noise generated during a starting failure of the engine (20), in addition to allow the piston (15) to be positioned in a position more favorable to a new start.

A plunger lift system, as well as a method for monitoring plunger parameters within a wellbore using such a plunger lift system, are provided. The plunger lift system includes a lubricator attached to a wellhead at the surface and a plunger dimensioned to travel through the production tubing upon being released from the lubricator. The plunger lift system also includes magnetic sensor systems installed along the production tubing, where each magnetic sensor system includes a magnetic sensor for detecting the passage of the plunger as it travels through the production tubing, as well a communication device for transmitting communication signals between the magnetic sensor systems and a computing system located at the surface, where the computing system includes a processor and a non-transitory, computer-readable storage medium including computer-executable instructions that direct the processor to dynamically determine the plunger position and/or velocity based on the received communication signals.

A sensor apparatus is provided for transmitting data of a polished rod in a rod pumping system, the rod pumping system including a rod rotator that rotates the polished rod. The sensor apparatus includes an outer shell configured to receive the polished rod, a signal processor within the outer shell, a position sensor within the outer shell and configured to sense and output to the signal processor a position signal, and a magnetic pickup sensor configured to sense and output to the signal processor a signal indicating a sensed magnetic field. The signal processor is configured to count a number of strokes of the polished rod based on the position signal, and to determine whether a fault exists based on the number of strokes and the signal indicating the sensed magnetic field.

A monitoring method and dosing pump system monitor operation of a dosing pump including a dosing chamber (2), a displacement element (4) and an electric drive (12). A position (S) of the displacement element and a pressure (P) inside the dosing chamber are continuously recorded as a curve in a pressure-stroke diagram. The method includes monitoring at least one characteristic portion (36, 38, 40, 42, B, C) of the curve in the pressure-stroke diagram by detecting a possible shift (A) of the characteristic portion over several strokes. The method further includes one or both of: adjusting a control of the electric drive based on the detected shift; and determining a trend of the shift over several strokes of the displacement element and determining based on the trend whether and/or when the shift will reach a predefined limit. A dosing pump system with the dosing pump execute the method.

A compressor control apparatus and method differently compensate for a duty ratio of a control signal during a period in which the compressor performs a compression stroke and a period in which the compressor performs a suction stroke, respectively, to generate the control signal for controlling a compressor.

A gas booster for increasing a pressure of a gas includes a gas cylinder and a drive. The gas cylinder defines a chamber having an inlet and an outlet. A piston is actuatable within the gas cylinder to draw gas into the chamber through the inlet at a first pressure and to push the gas out of the chamber through the outlet at a second pressure that is higher than the first pressure. The drive includes an electric motor coupled to the piston of the gas cylinder by a mechanical connection to actuate the piston.

Apparatus and methods for determining operational health of a pump. An example method may include commencing operation of a processing device to monitor operational health of a pump for pumping a fluid at a wellsite, wherein the pump may be a reciprocating pump. During pumping operations of the pump, the processing device may receive pressure measurements of the fluid at a fluid inlet manifold and/or a fluid outlet manifold of the pump, receive position measurements of fluid displacing members of the pump, detect irregular pressure measurements based on the received pressure measurements, determine operational phase of the pump based on the received position measurements, and determine which of fluid inlet and outlet valves of the pump is leaking based on operational phase during which the irregular pressure measurements are detected.

Systems and methods for controlling downhole linear motors to minimize connections to surface equipment. In one embodiment, an ESP system is coupled by a power cable to equipment at the surface of a well. The ESP system includes a linear motor and a reciprocating pump. The motor has a set of position sensors that sense the position of a mover in the motor. Combining circuitry (E.G., XOR gate) combines the outputs of the position sensors into a single composite signal in which signal components corresponding to the position sensors are indistinguishable. A single channel carries the composite signal from the ESP system to the surface equipment. A control system determines a starting position of the motor and determines its subsequent position based on transitions in the composite signal. The motor is then operated based on the position determined from the composite signal.