A centrifugal pump including an outer case; an inner case; a first unit and a second unit placed in fluid communication with each other, each unit including a plurality of impellers; the inner case includes two half-parts joined along a connection plane containing the axis of rotation; a connecting element is placed between the first unit and the second unit, the connecting element is engaged with a last impeller of the first unit and with a last impeller of the second unit.

An assembly structure of a multi-stage impeller and wheel housing for use in a submersible pump that includes a connecting seat having a drainage channel, shaft, intermediate unit which has a wheel housing, inner guide cover, and impeller. The wheel housing has a central partition plate, with an upper ring housing and lower ring canopy extending upward and downward, respectively, along the perimeter of the central partition plate. The intermediate unit has the upper ring housing connected to the canopy of the connecting seat by a swivel snap structure. A bottom unit has a bottom impeller and bottom wheel housing, which has a water suction port, a bottom plate and a bottom ring housing that extends upward along the perimeter of the bottom plate. A bottom ring canopy of an intermediate unit is connected by a rotating snap structure, and the bottom ring housing is pressed by a sealing ring.

A pumping module is positionable within a pump housing for pumping fluid into a wellbore. The pumping module includes a cylindrical housing with an inlet end and an outlet end, an inlet cap positioned on the inlet end of the cylindrical housing and including an inlet formed through the inlet cap, and an outlet cap positioned on the outlet end of the cylindrical housing and including an outlet formed through the outlet cap. A shaft is rotatable with respect to the cylindrical housing, and a rotor is positioned within the cylindrical housing and rotatable by the shaft to push fluid through the cylindrical housing.

A centrifugal pump assembly includes a pump head, a pump base defining a pump inlet and a pump outlet, a fluid outlet channel from the pump head to the pump outlet, impellers, defining an impeller fluid channel between an impeller inlet and outlet and connected with one of rotor shaft segments including a positive fit coupling for torque transfer between at least two rotor shaft segments, and one or more pump stage housing segments arranged between the pump base and the pump head. The pump stage housing segments have a structure defining a guide passage for receiving pumped fluid from the impeller outlet of the impellers and for guiding pumped fluid to the impeller inlet of another one of the impellers or to the pump head. The pump stage housing segments each have a structure defining at least a part of a wall section of the fluid outlet channel.

A downhole gas separator fluid mover assembly comprising a fluid mover having an inlet and an outlet, a separation device, a separation chamber, and a flow path separator located downstream of the fluid mover. The fluid mover comprising a centrifugal pump stage with an impeller and a diffuser moves production fluid comprising a high viscosity fluid portion and a gas portion to the separation device. The separation device produces a fluid motion that separates the gas phase from the liquid phase in response to the flow rate of production fluid from the fluid mover. A portion of the high viscosity fluid passes through the gas phase discharge port in response to the over-supply of high viscosity fluid to the liquid discharge port in response to the flow rate of the production fluid through the fluid mover.

An assembly structure of a multi-stage impeller and wheel housing for use in a submersible pump that includes a connecting seat having a drainage channel, shaft, intermediate unit which has a wheel housing, inner guide cover, and impeller. The wheel housing has a spacer, with an upper ring housing and lower ring canopy extending upward and downward, respectively, along the perimeter of the spacer. The intermediate unit has the upper ring housing connected to the canopy of the connecting seat by a swivel snap structure. A bottom unit has a bottom impeller and bottom wheel housing, which has a water suction port, a bottom plate and a bottom ring housing that extends upward along the perimeter of the bottom plate. A bottom ring canopy of an intermediate unit is connected by a rotating snap structure, and the bottom ring housing is pressed by a sealing ring.

A first fluid rotor that has a first fluid intake end and a first fluid discharge end. A second fluid rotor that has a second fluid intake end and a second fluid discharge end. The second fluid rotor is rotatably coupled to the first fluid rotor to rotate in unison with the first fluid rotor along a shared rotational axis. The first fluid intake end and the second fluid intake end are facing opposite directions. A first fluid stator surrounds the first fluid rotor. The first fluid rotor and the first fluid stator form a first fluid stage. The second fluid stator is aligned along the rotational axis. The second fluid stator and the second fluid rotor form a second fluid stage. A flow crossover sub is positioned between the first fluid stage and the second fluid stage.

A cylindrical rotor inside of the cylindrical stator, wherein the cylindrical rotor has a screw thread with an opposite direction relating to the stator screw thread, wherein the rotor has a curvilinear external surface shape and a stator having an internal semicircular surface shape wherein rotor external surface shape and the stator has an internal surface shape having rounded shapes without rectangular edges to obtain high speed performance with reduced vortices, wherein a gap between the internal surface of the stator and the external surface of the rotor is 0.1-0.2 millimeters and an unloading thrust bearing attached to the rotor shaft positioned between intake thrust bearing and the intake end of the rotor and a cavity in the unloading thrust bearing configured to receive production fluid from the discharge end of the rotor.

A technique employs a system and methodology for improving sand control in pumps. The technique may be used in centrifugal pumps by providing uniquely constructed rib feature to facilitate sand control and thus reduction of erosion due to sand in the pumped fluid. The improved sand control is useful in centrifugal pumps employed in a variety of oilfield applications, such as in electric submersible pumping systems positioned downhole in a wellbore to pump oil or other fluids. The rib feature may be used in combination with a shield and arranged along diffuser bowl walls or other diffuser walls within sequential pump stages.

A submersible well pump has diffusers fixed within the housing and an impeller mounted between each of the diffusers. Spacer sleeves located between and in abutment with hubs of adjacent ones of the impellers define a stack wherein the impellers rotate in unison with the shaft and are axially movable in unison with each other relative to the shaft. A stop shoulder on the shaft abuts the lower end of the stack. A spring mounted in compression around the shaft in abutment with the upper end of the stack urges the lower end of the stack against the stop shoulder. Upward movement of the stack requires further compression of the spring. Up thrust and down thrust gaps between each impeller and adjacent diffusers prevent up thrust and down thrust from being transferred to any of the diffusers.