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 system to provide power to a downhole-type tool includes a downhole-type electric motor that can be positioned in a wellbore and a variable speed drive electrically connected to the electric motor, in which the downhole-type electric motor can operate at rotary speeds of at least 6,000 rotations per minute (rpm), the variable speed drive can control and supply power to the electric motor when the electric motor is positioned at a downhole location inside the wellbore, and the variable speed drive can be at a surface of the wellbore.

A system to provide power to a downhole-type tool includes a downhole-type electric motor that can be positioned in a wellbore and a variable speed drive electrically connected to the electric motor, in which the downhole-type electric motor can operate at rotary speeds of at least 6,000 rotations per minute (rpm), the variable speed drive can control and supply power to the electric motor when the electric motor is positioned at a downhole location inside the wellbore, and the variable speed drive can be at a surface of the wellbore.

An artificial lift system for a horizontal well deploys a downhole pump and flexible bladder reservoir chamber to be used with a conventional rod pump. The rod pump is used in the vertical at the top of the curve. The flexible bladder reservoir chamber is connected to the rod pump intake. The downhole pump is set in the producing formation and is connected to the reservoir chamber by tubing. The lift system uses a compressor drive system to operate the downhole pump to move fluids from the producing formation to the reservoir chamber. The reservoir chamber uses the flexible chamber bladder that is filled with well fluids by operation of the downhole pump to provide a continuous supply of well fluids to the rod pump intake. Operation of the rod pump lifts fluids from the flexible chamber bladder without regard to the operation state of the downhole pump.

An artificial lift system for a horizontal well deploys a downhole pump and flexible bladder reservoir chamber to be used with a conventional rod pump. The rod pump is used in the vertical at the top of the curve. The flexible bladder reservoir chamber is connected to the rod pump intake. The downhole pump is set in the producing formation and is connected to the reservoir chamber by tubing. The lift system uses a compressor drive system to operate the downhole pump to move fluids from the producing formation to the reservoir chamber. The reservoir chamber uses the flexible chamber bladder that is filled with well fluids by operation of the downhole pump to provide a continuous supply of well fluids to the rod pump intake. Operation of the rod pump lifts fluids from the flexible chamber bladder without regard to the operation state of the downhole pump.

A pumping system pumps material or fluid downhole, for example, to perform a stimulation operation. The pumping system can include a hydraulic pump coupled to an intensifier. The intensifier may have a piston which allows for a small footprint as compared to an intensifier with a plunger. The hydraulic cylinder of the intensifier may be protected from the corrosive, erosive and/or abrasive effects of the material or fluid to be pumped by one or more seals. Using the intensifier that includes a piston may provide for a greater reliability of the overall pumping system, as fewer strokes are required, and a compact pumping system, as the stroke length of the intensifier with a piston is less than the stroke length required for a plunger.

A pumping system pumps material or fluid downhole, for example, to perform a stimulation operation. The pumping system can include a hydraulic pump coupled to an intensifier. The intensifier may have a piston which allows for a small footprint as compared to an intensifier with a plunger. The hydraulic cylinder of the intensifier may be protected from the corrosive, erosive and/or abrasive effects of the material or fluid to be pumped by one or more seals. Using the intensifier that includes a piston may provide for a greater reliability of the overall pumping system, as fewer strokes are required, and a compact pumping system, as the stroke length of the intensifier with a piston is less than the stroke length required for a plunger.

Pumps are provided, more particularly piston type pumps having increased energy efficiency, systems incorporating such piston type pumps, and methods of operating piston type pumps. The pumps are suitable for pumping of oil from an oil well or for pumping other liquids such as ground water, subterranean liquids, brackish water, sea water, waste water, cooling water, gas, coolants, and the like.

Pumps are provided, more particularly piston type pumps having increased energy efficiency, systems incorporating such piston type pumps, and methods of operating piston type pumps. The pumps are suitable for pumping of oil from an oil well or for pumping other liquids such as ground water, subterranean liquids, brackish water, sea water, waste water, cooling water, gas, coolants, and the like.

A tool includes a device including a housing and a rotor, the rotor to rotate about a longitudinal axis, and an axial gap generator including a stator assembly positioned adjacent to the rotor. The axial gap generator generates a voltage signal as a function of a gap spacing between the stator assembly and the rotor, the gap spacing being parallel to the longitudinal axis.