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.

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.

A pumping method can include displacing a rod string with pressure applied to an actuator by a pressure source including an accumulator and a separate gas volume in communication with the accumulator. A sensor indicates whether a fluid is in the gas volume. A pumping system can include an actuator, a pump connected between the actuator and an accumulator, a hydraulic fluid contacting a gas in the accumulator, a separate gas volume in communication with the accumulator, and a sensor that detects the hydraulic fluid in the gas volume. Another pumping system can include an actuator, a pump connected between the actuator and an accumulator that receives nitrogen gas from a nitrogen concentrator assembly while a hydraulic fluid flows between the pump and the actuator, a separate gas volume in communication with the accumulator, and a sensor that detects a presence of the hydraulic fluid in the gas volume.

A hydraulic pumping system can include an actuator including a piston rod that displaces in response to pressure in the actuator, a seal assembly that seals about the piston rod and is exposed to the pressure in the actuator, and another seal assembly that seals about the piston rod, is exposed to pressure in a well and includes multiple separate seal cartridges, each of the seal cartridges including a dynamic seal that slidingly and sealingly engages the piston rod. Another hydraulic pumping system can include an actuator including a piston rod that displaces in response to pressure in the actuator, a seal assembly that seals about the piston rod and is exposed to the pressure in the actuator, and another seal assembly that seals about the piston rod, is exposed to pressure in a well and includes a labyrinth ring comprising multiple ring layers.

A fracturing apparatus, a control method of the fracturing apparatus and a fracturing system. The fracturing apparatus includes a plunger pump, a prime mover, a clutch and a clutch hydraulic system. The prime mover includes a power output shaft, and the clutch includes a first connection portion, a second connection portion and a clutch portion between the first connection portion and the second connection portion. The power end of the plunger pump includes a power input shaft, the first connection portion is connected with the power input shaft, the second connection portion is connected with the power output shaft of the prime mover, and the clutch hydraulic system is configured to provide hydraulic oil to the clutch. The fracturing apparatus further includes a first pressure sensor arranged in the clutch hydraulic system and configured to detect the hydraulic pressure of the clutch hydraulic system.

A system for monitoring a piece of hydraulic fracturing equipment such as a positive displacement pump. The system includes a plurality of sensors configured to detect conditions of the hydraulic fracturing pump and a processor that is communicatively coupled to the plurality of sensors and configured to analyze data received from the plurality of sensors. The processor is also configured to predict faults in the hydraulic fracturing pump based on the data analysis. The system also includes a communication interface that is configured for transmitting predicted fault data to one or more devices.

Provided is a dynamic characteristic measurement method for a cylinder block of a non-intrusive axial piston pump. The cylinder block is the main rotating component of the axial piston pump, and the dynamic characteristic of the cylinder block is more capable of reflecting the health condition of the pump than an external characteristic. A non-contact type measurement scheme is provided so as to reduce the influence of a measurement device on the motion of the cylinder block. Cylinder block contour signals and radial displacement signals are obtained by measuring the radial displacement of two sections of the surface of the cylinder block under different working conditions in the perpendicular directions, and then the cylinder block contour signals are accurately removed from the radial displacement signals to obtain the translational and tilting motion characteristics of the cylinder block.