Abstract: An electric submersible motor is provided that includes a plurality of rotors and bearings mounted on a shaft, and a stator external to said rotors. A running clearance is located between an inner diameter of the stator and external diameter of the rotors, and includes a lubricating oil that includes a base hydrocarbon oil and a plurality of nanoparticles. Also provided is an improved lubricant oil and method of preparation thereof are provided. The lubricant oil includes a hydrocarbon containing base oil and a plurality of nanoparticles. The nanoparticles may be present in an amount up to 30% by volume.

Abstract: A submersible electric motor has feature to enhance thermal conductivity from the motor interior to the exterior. The motor has a cylindrical housing and a stator rigidly mounted within housing. A rotatable rotor is located within the stator. A gap formed between the stator's outer diameter and the inner wall of the housing is filled with a high thermal conductivity material to improve heat transfer from the motor. The remaining portion of the housing may be filled with a dielectric lubricant that has lesser thermal conductivity than the high thermal conductivity material.

Abstract: A submersible pumping system for use downhole, wherein the system includes a pump, an inlet section for receiving fluid, a pump motor, and a viscometer. Pumping system operating parameters are adjusted based on wellbore fluid viscosity measured by the viscometer.

Abstract: Pump apparatus and methods of making and using same are disclosed. One inventive apparatus includes at least two pump stages having different performance characteristics combined in series to substantially match an intended pumping application. An inventive method includes selecting two or more pump stages having different performance characteristics that when combined in series overcome limitations of at least one of the pump stages.

Abstract: A system for accommodating thermal expansion of a pump housing. The system includes a pump having an external housing, and a mounting structure for mounting the pump. Contacting members are disposed intermediate the mounting structure and the pump for allowing one-dimensional movement of the external housing along a longitudinal axis of the external housing. Alternatively, bearing members are positioned to support the pump in the mounting structure, while allowing a thermal distortion of the housing.

Abstract: A system allows the pumping of viscous fluids from a wellbore. The system includes a submergible pump and a pump intake through which a fluid may be drawn. A submergible electric motor powers the submergible pump, and a heater is connected in the pumping system to heat the wellbore fluid. Additionally, a combination of heaters may be employed to heat the desired production fluid both externally to the pumping system and internally to the pumping system.

Abstract: A submergible, centrifugal pump utilizes an improved bushing system for absorbing downthrust at each stage of the pump. The centrifugal pump is a multi-stage pump having a plurality of impellers keyed to a rotatable shaft. Diffusers cooperate with the impellers to conduct the pumped fluid upwardly from one impeller to the next. The improved support system comprises simple diffuser bushings that are generally cylindrical in shape, and relatively inexpensive to manufacture. Each diffuser bushing is disposed between a diffuser and the next upwardly sequential impeller to support that impeller with respect to the downthrust created during pumping.

Abstract: A gas compressor is employed downhole in a well for pressurizing formation gas. The gas compressor is driven by a downhole electrical motor. The downhole assembly also includes a pump. The pump might be located below the motor and driven by the same motor. In that event, the pump pumps liquid being produced by the formation downward to a liquid disposal formation. Also, the pump may pump the liquid to the surface, with the gas being delivered into a repressurizing zone.

Abstract: A gas separator for a submersible centrifugal pump for a well separates gas from liquid components of the well fluid. The gas separator has a rotatably driven rotor. The rotor has an outer cylinder, an inner hub and a longitudinal vane that extends between the inner hub and outer cylinder. Notches are formed in the upper edge of the vanes. A discharge member, mounted above the rotor, has a depending skirt that extends into the notches. This defines a separate inner flow path for gas to flow out of the separator into the well. The unseparated portions of the well fluid flow in a clearance between the skirt and the housing into a pump intake. Supports extend out from the discharge member for securing the discharge member in the housing.

Abstract: A submersible centrifugal pump has a downward thrust washer of reduced diameter. The pump has a housing containing a plurality of stages of impellers and diffusers. Each impeller is rotated by a shaft for discharging fluid upward and outward into an intake of a diffuser. A counterbore is formed in the upper end of a bore that passes axially through the diffuser. An upward facing shoulder is located at the lower end of the counterbore. A thrust washer is located on the shoulder. An extension sleeve extends downward from the hub of each impeller into the counterbore of the diffuser of a next lower stage. Downward thrust on the impeller is transmitted through the extension sleeve to the thrust washer.