Abstract: Vibration of an electric submersible pump assembly is monitored to produce a vibration spectrum. The vibration spectrum is compared to a known vibration signature for a pump condition that precedes gas lock. The pump condition is at least one of an impeller rotating stall condition, a diffuser stall condition, a pre-surge condition, and percentage of free gas within the wellbore fluid. Operation of the pump is then adjusted in response to the similarity of the vibration spectrum to the vibration signature for the pump condition to prevent impending gas lock.

Abstract: A gas separator having an improved flowpath for lighter fluids having a higher concentration of gas decreases total pumping head for an ESP assembly. The ESP assembly includes a rotary primary pump, a motor coupled to the primary pump for driving the pump, a seal assembly between the primary pump and the motor, and a gas separator between the seal assembly and the primary pump. An outlet of the gas separator feeds an intake of the primary pump, and a rotating shaft operationally couples the primary pump to the motor and passes through the seal assembly and the gas separator. The gas separator contains a venting portion, and a diverter positioned within the venting portion having diverter guide vanes formed in a flowpath of the lighter fluid for aiding in a directional change of fluid momentum. A slinger is positioned within the diverter for impelling fluid through the venting port.

Abstract: Devices and methods for detecting operational parameters associated with a gas separator used in an electric submersible pump in a wellbore. A fiber optic sensing arrangement is used to detect the operational parameter and includes a fiber optic signal processor and an optic fiber that is associated with the gas separator to provide a signal indicative of the parameter to the signal processor.

Abstract: A submersible pumping system, electrical submersible pump, and method of providing enhanced alignment of motor and driven shafts of submersible pumping systems and electrical submersible pumps, are provided. An example of an electrical submersible pump system includes a pump, a pump motor, and a seal section. The motor drives the pump via motor and driven shafts rotatingly coupled with a coupling assembly. The coupling assembly maintains the shaft ends in coaxial alignment with an alignment device. The alignment device is profiled on opposite ends for mating engagement with the centering guides extending from the shaft ends.

Abstract: A submersible pumping system, electrical submersible pump, and method of providing enhanced alignment of motor and driven shafts of submersible pumping systems and electrical submersible pumps, are provided. An example of an electrical submersible pump system includes a pump, a pump motor, and a seal section. The motor drives the pump via motor and driven shafts rotatingly coupled with a coupling assembly. The coupling assembly maintains the shaft ends in coaxial alignment with an alignment device. The alignment device is profiled on opposite ends for mating engagement with the centering profiles extending into the shaft ends.

Abstract: A gas separator having an improved flowpath for lighter fluids having a higher concentration of gas decreases total pumping head for an ESP assembly. The ESP assembly includes a rotary primary pump, a motor coupled to the primary pump for driving the pump, a seal assembly between the primary pump and the motor, and a gas separator between the seal assembly and the primary pump. An outlet of the gas separator feeds an intake of the primary pump, and a rotating shaft operationally couples the primary pump to the motor and passes through the seal assembly and the gas separator. The gas separator contains a venting portion, and a diverter positioned within the venting portion having diverter guide vanes formed in a flowpath of the lighter fluid for aiding in a directional change of fluid momentum. A slinger is positioned within the diverter for impelling fluid through the venting port.

Abstract: An electrical submersible pump (ESP) having a sleeve coupled to the shaft that rotates as the shaft rotates. The sleeve can be a base portion of a pump impeller, a journal bearing, or a bushing. A drive collar mounts around the shaft and has an end with a portion that projects past an end of the sleeve profiled to correspond with the shape of the projecting portion. As the shaft rotates the drive collar the projecting portion of the drive collar pushes against the profiled end of the sleeve to rotate the sleeve. The projecting portion can be a wedge shaped tab on the drive collar, or an angular segment of the drive collar extending axially past the remaining segments. The profiled end of the sleeve can include a recess formed to receive the tab and can have an angular segment corresponding to that on the drive collar.

Abstract: A two-phase, homogenizing or mixing stage for a centrifugal pump assembly homogenizes the fluids being circulated therethrough. The mixing stage produces high shut-in head pressure and a very high maximum flow rate. The mixing stage has a diffuser with fixed diffuser vanes that extend radially or tangentially at acute angles. The vanes may be curved in both the axial and radial directions to force fluids impinging thereon to have a radially inward component to create turbulence. The turbulence mixes and homogenizes the gas and liquid fluids to improve the overall performance of centrifugal pump assemblies that operate in two-phase fluids. The mixing stage also has an impeller adjacent the diffuser. The impeller vanes likewise extend radially and tangentially therefrom at acute angles and may be curved.

Abstract: Vibration of an electric submersible pump assembly is monitored to produce a vibration spectrum. The vibration spectrum is compared to a known vibration signature for a pump condition that precedes gas lock. The pump condition is at least one of an impeller rotating stall condition, a diffuser stall condition, a pre-surge condition, and percentage of free gas within the wellbore fluid. Operation of the pump is then adjusted in response to the similarity of the vibration spectrum to the vibration signature for the pump condition to prevent impending gas lock.

Abstract: The pump can be utilized in gassy oil wells to prevent gas slugs from locking the electrical submersible pump. A shroud assembly is provided with a bottom that can be fixed to the top of a seal section connected to the top of a motor. Additional lengths of shroud can be added as the shroud assembly is lowered into the well. The electrical submersible pump can then lowered into the shroud and supported from a production tubing string. A hanger can then be attached to the production tubing string to carry the weight of the shroud assembly, motor, and seal section.

Abstract: A seafloor pump assembly is installed within a caisson that has an upper end for receiving a flow of fluid containing gas and liquid. The pump assembly is enclosed within a shroud that has an upper end that seals around the pump assembly and a lower end that is below the motor and is open. An extraction tube has an upper end above the shroud within the upper portion of the caisson and a lower end connected to a jet pump. The extraction tube causes gas that separates from the liquid and collects in the upper portion of the caisson to be drawn into the jet pump and mixed with the liquid as the liquid is being pumped.

Abstract: Submersible pumps, diffuser assemblies, and related methods for pumping a fluid having a substantial sand content, are provided. A diffuser assembly for a submersible pump can include anti-swirl ribs forming sand dams positioned on an upper surface of the diffuser bowl floor at an acute angle to guide trapped between the bottom shroud of an impeller and the diffuser bowl to the inner surface of the diffuser bowl outer wall and back into the production fluid stream. The diffuser assembly can also include sand jump ramps each separately positioned adjacent the outer peripheral surface of one of the sand dams and positioned adjacent a separate portion of the inner surface of the diffuser bowl outer wall to further enhance deflection of sand back into the production fluid stream.

Abstract: A centrifugal pump has alternating impellers and diffusers. One or more vent holes extend through one or more vanes of one or more diffusers. In an upthrust condition, high pressure production fluid from an upper impeller is able to pass through the one or more vent holes, and thereby exert force on the preceding impeller. The force exerted on the preceding impeller offsets the upthrust force acting against the preceding impeller.

Abstract: A seafloor pump assembly is installed within a caisson that has an upper end for receiving a flow of fluid containing gas and liquid. The pump assembly is enclosed within a shroud that has an upper end that seals around the pump assembly and a lower end that is below the motor and is open. An eduction tube has an upper end above the shroud within the upper portion of the caisson and a lower end in fluid communication with an interior portion of the shroud. The eduction tube causes gas that separates from the liquid and collects in the upper portion of the caisson to be drawn into the pump and mixed with the liquid as the liquid is being pumped.

Abstract: The pump can be utilized in gassy oil wells to prevent gas slugs from locking the electrical submersible pump. A shroud assembly is provided with a bottom that can be fixed to the top of a seal section connected to the top of a motor. Additional lengths of shroud can be added as the shroud assembly is lowered into the well. The electrical submersible pump can then lowered into the shroud and supported from a production tubing string. A hanger can then be attached to the production tubing string to carry the weight of the shroud assembly, motor, and seal section.

Abstract: A submersible pumping system for use downhole that includes a housing, a pump and gas separator within the housing, a motor for driving the pump and separator, and a foaming agent injection system. The foaming agent injection system injects a foaming agent upstream of the pump and optionally upstream of the separator. The foaming agent injection system comprises a foaming agent supply, an injection pump, and foaming agent injection line.

Abstract: An electrical submersible well pump assembly having a progressing cavity pump, a pump motor, a flex shaft connecting the pump motor to the pump, and a gas/liquid separator on the inlet to the pump. An inner and outer housing circumscribe a portion of the flex shaft, each having fluid inlets. The fluid inlets on the outer housing are above the inner housing inlets and an annulus is formed between the inner and outer housing. Wellbore fluid enters the assembly through the outer housing inlets, flows downward through the annulus, and into the inner housing inlets. Gas separates from the liquid as the fluid flows downward from the outer housing inlets to the inner housing inlets.

Abstract: A submersible well pump assembly has a gas separator that separates gas prior to entering into the pump. A shroud encloses a portion of the pump assembly, including the gas separator. The gas separator has gas discharge tubes that extend from it out through the shroud. The gas discharge tubes are tangentially aligned to create a vortex on the exterior of the shroud.

Abstract: A seafloor pump assembly is installed within a caisson that has an upper end for receiving a flow of fluid containing gas and liquid. The pump assembly is enclosed within a shroud that has an upper end that seals around the pump assembly and a lower end that is below the motor and is open. An extraction tube has an upper end above the shroud within the upper portion of the caisson and a lower end connected to a jet pump. The extraction tube causes gas that separates from the liquid and collects in the upper portion of the caisson to be drawn into the jet pump and mixed with the liquid as the liquid is being pumped.

Abstract: An electrical submersible well pump assembly having a progressing cavity pump, a pump motor, a flex shaft connecting the pump motor to the pump, and a gas/liquid separator on the inlet to the pump. An inner and outer housing circumscribe a portion of the flex shaft, each having fluid inlets. The fluid inlets on the outer housing are above the inner housing inlets and an annulus is formed between the inner and outer housing. Wellbore fluid enters the assembly through the outer housing inlets, flows downward through the annulus, and into the inner housing inlets. Gas separates from the liquid as the fluid flows downward from the outer housing inlets to the inner housing inlets.