A liquid leak detector for a pump is described. The liquid leak detector is mountable on a pump to detect leaked fluid coming from the pump. The leak detector includes a buffer tube positioned on the pump to collect a leaked fluid from the pump and a sensor positioned on the buffer tube to detect the level of leaked fluid in the buffer tube and to generate a signal when the leaked fluid reaches a maximum fluid level. A purge line on the buffer tube removes leaked drive fluid from the buffer tube once the leaked drive fluid reaches a maximum level. Logic connected to the sensor receives the signal from the detector and generates an alarm.

A liquid leak detector for a pump is described. The liquid leak detector is mountable on a pump to detect leaked fluid coming from the pump. The leak detector includes a buffer tube positioned on the pump to collect a leaked fluid from the pump and a sensor positioned on the buffer tube to detect the level of leaked fluid in the buffer tube and to generate a signal when the leaked fluid reaches a maximum fluid level. A purge line on the buffer tube removes leaked drive fluid from the buffer tube once the leaked drive fluid reaches a maximum level. Logic connected to the sensor receives the signal from the detector and generates an alarm.

A method of producing fluid from a wellbore includes operating a pump located proximate to a zone of fluid influx in the wellbore to draw a reservoir fluid from a reservoir into the wellbore at the zone of fluid influx. The pump is coupled to a tubing string extending above the pump, and a packer is coupled to the tubing string proximate to an upper end of the zone of fluid influx and seals an annular space around the tubing string. The method includes operating the pump to produce the reservoir fluid from the wellbore through the tubing string. A pump includes a drive chamber with a drive piston, a production chamber with a production piston coupled to the drive piston, and axially separated traveling valves.

A fluid delivery device comprises a hydraulic pump chamber having a hydraulic fluid. A fluid reservoir is coupled to the hydraulic pump chamber and is configured to contain a fluid deliverable to a patient. A first actuator is coupled to the hydraulic pump chamber and is configured to pressurize the hydraulic pump chamber and configured to transfer energy through the hydraulic pump chamber to the fluid reservoir. A second actuator is coupled to the hydraulic pump chamber and is configured to pressurize the hydraulic pump chamber and configured to transfer energy through the hydraulic pump chamber to the fluid reservoir.

An infusion system includes a double action infusion pump. The pump includes a cylinder and a reciprocating piston received within the cylinder, the reciprocating piston separating a first pump chamber from a second pump chamber of the cylinder. A reciprocating motor is coupled with the reciprocating piston, and the first and second pump chambers alternate between filling and evacuating conditions with reciprocation of the reciprocating piston through operation of the reciprocating motor, and the speed of reciprocation is varied to provide a continuous output of fluid between the first and second pump chambers. A fluid source and a catheter are optionally coupled with the double action infusion pump. The catheter includes one or more infusion ports near a catheter distal portion, and the one or more infusion ports receive and expel the continuous output of fluid from the double action infusion pump.

A natural gas compressor can include a pre-staging chamber that couples with a supply line to receive natural gas from the supply line. The compressor can additionally include a first-stage chamber that couples with the supply line to receive natural gas from the supply line. The first-stage chamber can additionally be coupled with the pre-staging chamber to receive from the pre-staging chamber natural gas that has been compressed by the pre-staging chamber. The compressor can also include a second-stage chamber configured to receive natural gas that has been compressed by the first-stage chamber.

A method of producing fluid from a wellbore includes operating a pump located proximate to a zone of fluid influx in the wellbore to draw a fluid from a reservoir into the wellbore at the zone of fluid influx. A first section of a tubing string is coupled to, and extends above, the pump, and a second section of the tubing string is coupled to, and extends below, the pump. A packer seals a first annular space around the first section of the tubing string. The method further includes operating the pump to move the fluid from the second section of the tubing string and into the first section of the tubing string.

The invention relates to a system that intensifies hydraulic pressure, which comprises a main actuation subsystem and a direction-change sub-system. The main actuation subsystem comprises: a motor; a pump; a first piston with a plunger that moves linearly; a travel-limit sensor and a two-way valve at each end of the piston; a pressure control valve connected to the two-way valves; a second piston similar in always to the first and connected to the pressure control valve; a hydraulic motor connected to the two-way valves of the second piston to generate work; and a fluid-cooling means. The direction-change subsystem comprises a secondary motor, a second pump, a pressure accumulator and a pair of solenoid valves for the parallel and independent operation of the two-way valves of the main actuation subsystem.

A reversing valve for a hydraulic piston pump, including a pilot valve and a main valve. The pilot valve includes a pilot valve seat, a hollow valve core and a pull rod. The main valve comprises an upper valve seat, a lower valve seat and a main valve core. When the hollow valve core is at a upper position, the control flow passage communicates with the spent fluid flow passage, and the main valve core is at a lower position, so the power piston is driven to move downwardly by the power fluids provided by the main valve. When the hollow valve core is at a lower position, the power fluid controls the main valve core to be seated at the upper position, and the power piston is driven to move upwardly by the power fluids provided by the pilot valve.

A method of producing fluid from a wellbore includes operating a pump located proximate to a zone of fluid influx in the wellbore to draw a fluid from a reservoir into the wellbore at the zone of fluid influx. A first section of a tubing string is coupled to, and extends above, the pump, and a second section of the tubing string is coupled to, and extends below, the pump. A packer seals a first annular space around the first section of the tubing string. The method further includes operating the pump to move the fluid from the second section of the tubing string and into the first section of the tubing string.