A method of controlling a gas compression system includes comparing an engine load of an engine of the gas compression system during operation to a load threshold and controlling a suction valve coupled to an intake of a reciprocating compressor. The suction valve is controlled based at least in part on the comparison of the engine load to the load threshold. Controlling the suction valve includes incrementing the suction valve toward a closed position to reduce flow of a gas into the intake when the engine load is greater than or equal to the load threshold.

An air compressor system includes a motor operably connected to an air compressor, a separator tank fluidly connected to the air compressor by a supply line, a compressed air line coupled to the separator tank, a service valve connected to the compressed air line and positioned downstream of the separator tank, and a controller in operable communication with the motor, wherein in response to the controller detecting the motor operating at an idle speed, the controller reduces the motor speed to a low idle speed and reduces pressure in the separator tank, the low idle speed being slower than the idle speed.

Provided is a forced-regeneration treatment method for an exhaust-gas aftertreatment device (DPF) and an associated engine-driven compressor. When the amount of particulate matter (PM) deposited in a filter element of a DPF reaches a predetermined amount and a forced-regeneration start command is input, a capacity controlling means of the engine-driven compressor is disabled to close an intake valve and to open the discharge side of a compressor main unit to atmosphere, thereby causing the compressor main unit to achieve a low-load state. The operation mode of the engine is switched to a predetermined forced-regeneration mode to operate the engine at a predetermined speed and to increase the temperature of the gas. The temperature inside the DPF is increased to reach a temperature at which an oxidative catalyst is activated and to a temperature lower than the self-combustion temperature of the PM, thereby forcibly burning the PM.

An oilfield pressure pumping system is configured to perform a preliminary fracturing stage or operation at a high pressure but slow speed before initiating normal fracturing. The oilfield pressure pumping system includes an auxiliary underdrive system that can drive the transmission at a slower input speed that can be provided by an idle speed of the power unit's engine to facilitate different fracturing modes, including a preliminary fracturing mode during a slow speed high pressure preliminary fracturing stage. The auxiliary underdrive system may include a hydrostatic transmission driven by the engine and which drives the transmission at an underdrive speed that would correspond to a sub-idle engine speed driving the transmission.

A pumping system pumps material downhole, for example, to perform a fracturing operation. The pumping system comprises one or more variable speed engines, one or more variable displacement hydraulic pumps and one or more intensifiers. According to the desired or required load, the speed of the engine is set at an optimal or most efficient operating speed. The volumetric displacement of the variable displacement hydraulic pump is set to provide the desired output volume and pressure of the material from the intensifier. Varying the speed of the engine and the volumetric displacement of the variable displacement pump allows for the pumping system and in particular the engine to operate at an optimal efficiency which reduces at least fuel costs and wear and tear on components.

A hydraulic actuator includes a variable-delivery positive-displacement pump, a member able to continuously vary the delivery of the pump, the member being actuated by a ram supplied by a first directional-control valve commanded on the basis of an actuator movement instruction. The actuator comprises a second directional-control valve commanded on the basis of an output pressure of the pump, the second directional-control valve comprising two positions, one of them, known as the rest position, obtained as long as the output pressure of the pump is below a predetermined pressure and transmitting the output from the first directional-control valve to the double-acting ram and the other, referred to as the active position, transmitting the output pressure of the pump to the ram so as to reduce the output pressure of the pump without passing via the first directional-control valve.

An oilfield pressure pumping system is configured to perform a preliminary fracturing stage or operation at a high pressure but slow speed before initiating normal fracturing. The oilfield pressure pumping system includes an auxiliary underdrive system that can drive the transmission at a slower input speed that can be provided by an idle speed of the power unit's engine to facilitate different fracturing modes, including a preliminary fracturing mode during a slow speed high pressure preliminary fracturing stage. The auxiliary underdrive system may include a hydrostatic transmission driven by the engine and which drives the transmission at an underdrive speed that would correspond to a sub-idle engine speed driving the transmission.

An example system includes a fluid end having a block, a fluid inlet formed in the block, and a fluid outlet formed in the block. The system also includes an intake manifold fluidly coupled to the fluid inlet, and a fluid conduit fluidly coupled to the fluid outlet and the intake manifold. The system further includes a valve fluidly coupled to the fluid conduit, the valve configured to control fluid flow through the fluid conduit, an actuator coupled to the valve and configured to position the valve in an open position or a closed position, and a controller communicatively coupled to the actuator and configured to send one or more signals to the actuator, causing the actuator to position the valve in the open position or the closed position.

An oscillation controller operates on engine speed or RPM data from a pump or pumping unit associated with a wellbore operation. The oscillation controller determines a measure of variability, such as a bandwidth, for the engine speed over a rolling time window and compares the measure of variability to an oscillation bandwidth threshold. The oscillation controller determines that erratic behavior or oscillation is present when the measure of variability exceeds the oscillation bandwidth threshold, and for such instances measures a duration of erratic behavior with a variability timer. If the oscillation controller determines that the erratic behavior has subsided, the variability timer is cleared. The oscillation controller generates at least one warning whenever the variability timer exceeds an oscillation warning threshold. The oscillation controller mitigates erratic behavior by downshifting (or shifting to neutral) at least one gear of the pump or pumping unit if the variability timer exceeds an oscillation mitigation time threshold.

A pumping system for performing a borehole operation including pumping a fluid into a borehole. The system may include a motor, a transmission, a pump, and a control system. The motor, transmission, and pump may each include sensors. The transmission may be operatively coupled to the motor. The pump may be operatively coupled to the transmission and configured to pump fluid into the borehole. The control system may be in communication with the motor sensors, the transmission sensors, and the pump sensors. The control system may be configured to monitor the operation of the motor, the transmission, and the pump, determine if at least one of the motor, the transmission, or the pump is operating outside of predetermined parameters, and determine at least one component of the motor, the transmission, or the pump that is most likely to cause the operation to be outside of the predetermined parameters.