The present invention discloses a hydraulically-driven double-acting mud pump, comprising power motors, pressure oil pumps, a three-position four-way hydraulically-actuated directional valve, a hydraulic power end and a mud pump head, the power motors being connected to the pressure oil pumps in a conventional way, the pressure oil pumps being communicated with a port P of the three-position four-way hydraulically-actuated directional valve via a pipeline, a port T of the three-position four-way hydraulically-actuated directional valve being communicated with an oil tank via a pipeline, a port A and a port B of the three-position four-way hydraulically-actuated directional valve being both connected to the hydraulic power end, the hydraulic power end being connected to the mud pump head in a conventional way, a lower end of the mud pump head being communicated with a low-pressure manifold and two sides of the mud pump head being communicated with a high-pressure manifold. The hydraulically-driven double-acting mud pump of the present invention allows for more stable instantaneous flow and pressure of the discharged liquid from the mud pump and reduced fluctuation.

Automated systems are disclosed that enable the rapid provision of fluids to downhole isolation tools. This is achieved by automatically optimizing the use of power available downhole by providing a high flowrate when pressure demand is low and a lower flowrate when pressure demand is high. Methods are disclosed which utilize the apparatus in a bottom hole assembly during downhole operations for isolating segments of a borehole.

Automated systems are disclosed that enable the rapid provision of fluids to downhole isolation tools. This is achieved by automatically optimizing the use of power available downhole by providing a high flowrate when pressure demand is low and a lower flowrate when pressure demand is high. Methods are disclosed which utilize the apparatus in a bottom hole assembly during downhole operations for isolating segments of a borehole.

An apparatus includes a linear motor and a fluid pump functionally connected to the linear motor. A fluid inlet of the fluid pump is in fluid communication with a fluid source. A fluid outlet of the fluid pump in fluid communication with a well. A pressure sensor is in fluid communication with the well. A controller is functionally coupled to the linear motor and the pressure sensor, wherein the controller is configured to operate the fluid pump to maintain a selected pressure in the well.

An apparatus includes a linear motor and a fluid pump functionally connected to the linear motor. A fluid inlet of the fluid pump is in fluid communication with a fluid source. A fluid outlet of the fluid pump in fluid communication with a well. A pressure sensor is in fluid communication with the well. A controller is functionally coupled to the linear motor and the pressure sensor, wherein the controller is configured to operate the fluid pump to maintain a selected pressure in the well.

A compressor device that periodically supplies compressed working gas to a cooling device loses less of the gas by not using rotary valves. The compressor device includes a compressor cylinder, a compensation container and a drive device with an hydraulic cylinder. The compressor cylinder includes a compressor element, such as a piston or membrane, that divides the compressor cylinder into first and second volumes. The first volume contains the gas that is compressed by the compressor element. The hydraulic cylinder has a piston that is coupled to the compressor element. The compensation container contains compensation fluid and is directly connected to the second volume. The compensation container is also connected to the first volume by a gas line with a non-return valve that opens in the direction of the first volume. The drive device allows the compressed gas to be provided at a frequency required for Gifford-McMahon and pulse-tube coolers.

A compressor device that periodically supplies compressed working gas to a cooling device loses less of the gas by not using rotary valves. The compressor device includes a compressor cylinder, a compensation container and a drive device with an hydraulic cylinder. The compressor cylinder includes a compressor element, such as a piston or membrane, that divides the compressor cylinder into first and second volumes. The first volume contains the gas that is compressed by the compressor element. The hydraulic cylinder has a piston that is coupled to the compressor element. The compensation container contains compensation fluid and is directly connected to the second volume. The compensation container is also connected to the first volume by a gas line with a non-return valve that opens in the direction of the first volume. The drive device allows the compressed gas to be provided at a frequency required for Gifford-McMahon and pulse-tube coolers.

An apparatus includes a linear motor and a fluid pump functionally connected to the linear motor. A fluid inlet of the fluid pump is in fluid communication with a fluid source. A fluid outlet of the fluid pump in fluid communication with a well. A pressure sensor is in fluid communication with the well. A controller is functionally coupled to the linear motor and the pressure sensor, wherein the controller is configured to operate the fluid pump to maintain a selected pressure in the well.

An apparatus includes a linear motor and a fluid pump functionally connected to the linear motor. A fluid inlet of the fluid pump is in fluid communication with a fluid source. A fluid outlet of the fluid pump in fluid communication with a well. A pressure sensor is in fluid communication with the well. A controller is functionally coupled to the linear motor and the pressure sensor, wherein the controller is configured to operate the fluid pump to maintain a selected pressure in the well.

A linearly actuated hydraulic piston pump is provided. The pump includes a piston disposed between a first section and a second section of a piston chamber. The pump also includes a control valve having a valve body defining a valve chamber therein. The control valve also includes an inlet port, a first port, a regeneration port, a second port, and a spool. The spool in a first spool position fluidly couples a pressurized fluid source to the first section via the inlet port and the first port, and fluidly couples an accumulator to the second section via the regeneration port and the second port. The spool in the second spool position fluidly couples the first section to a drain via the first port and a drain port, and fluidly couples the second section to the pressurized fluid source via the inlet port and the second port.