A cylindrical gap is formed between a production pipe and a pump stator, the pump stator has a tubular pump casing that surrounds a plurality of pump bodies, the pump casing is provided with a penetrating portion that penetrates the pump casing in a radial direction and communicates with the gap, and the penetrating portion is formed in a portion of the pump casing that faces a pump body, which is located in an intermediate stage of the plurality of pump bodies, in the radial direction.

An apparatus for generating acoustic waves within a medium to stimulate oil recovery within an oil reservoir. The apparatus is operable with a single moving part—a central rotor, and the rotor further includes a “conduit” through which the supply fluid passes.

An apparatus for generating acoustic waves within a medium to stimulate oil recovery within an oil reservoir. The apparatus is operable with a single moving part—a central rotor, and the rotor further includes a “conduit” through which the supply fluid passes.

A rotary drive actuator for an annular well pressure control device includes a piston having a tapered inner surface, a through bore and a threaded outer surface. A threaded sleeve having a threaded inner surface is in threaded engagement with the threaded outer surface of the piston. A rotary motor is arranged to rotate the threaded sleeve, whereby rotation of the rotary motor causes corresponding axial motion of the piston.

A rotary drive actuator for an annular well pressure control device includes a piston having a tapered inner surface, a through bore and a threaded outer surface. A threaded sleeve having a threaded inner surface is in threaded engagement with the threaded outer surface of the piston. A rotary motor is arranged to rotate the threaded sleeve, whereby rotation of the rotary motor causes corresponding axial motion of the piston.

An electrical submersible well pump assembly has first and second permanent magnet motors. The first motor drive shaft is connected to a coupling that has internal splines for receiving an externally splined end of the second motor drive shaft. Alignment devices rotationally align magnetic poles of the first drive shaft with the magnetic poles of the second drive shaft prior to securing the housings of the first and second motors together. The alignment devices may be a coupling irregularity in the internal splines that is at a controlled orientation relative to the magnetic poles of the first shaft and a shaft irregularity in the external splines that prevents the second drive shaft from fully engaging the coupling unless the shaft irregularity is in a specified rotational position relative to the coupling irregularity.

An electrical submersible well pump assembly has first and second permanent magnet motors. The first motor drive shaft is connected to a coupling that has internal splines for receiving an externally splined end of the second motor drive shaft. Alignment devices rotationally align magnetic poles of the first drive shaft with the magnetic poles of the second drive shaft prior to securing the housings of the first and second motors together. The alignment devices may be a coupling irregularity in the internal splines that is at a controlled orientation relative to the magnetic poles of the first shaft and a shaft irregularity in the external splines that prevents the second drive shaft from fully engaging the coupling unless the shaft irregularity is in a specified rotational position relative to the coupling irregularity.

Systems and methods for increasing hydrocarbon production using an electrical submersible pump are described. The methods typically include, for example, configuring an electrical submersible pump comprising a gas separator to induce a gas lift effect in a well comprising a tubing within a casing. Hydrocarbon production from the well is therefore increased using the electrical submersible pump.

Systems and methods for increasing hydrocarbon production using an electrical submersible pump are described. The methods typically include, for example, configuring an electrical submersible pump comprising a gas separator to induce a gas lift effect in a well comprising a tubing within a casing. Hydrocarbon production from the well is therefore increased using the electrical submersible pump.

An electric submersible pump (ESP) assembly. The ESP assembly comprises a centrifugal pump, an electric motor mechanically coupled by a drive shaft to the centrifugal pump, wherein the electric motor comprises a stator and a rotor, a bearing, wherein the bearing is disposed inside the electric motor, and a magnetic shield disposed in the electric motor between bearing and the rotor and stator.