Systems and features for improving sand control in pumps are provided. These features can be used 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. Such features include shielded anti-swirl ribs positioned in the balance chamber.

A thrust box with improved cooling comprises a case having an interior, a first passageway and an opposing second passageway. A shaft passes through the case and the first and second passageway. A thrust runner is secured to the shaft and a pump ring is attached to the thrust runner. Advantageously, the pump ring facilitates oil rate circulation and cooling among other benefits.

An electric submersible pump (ESP) assembly. The ESP assembly comprises an electric motor; a seal section; a fluid intake; a charge pump assembly located downstream of the fluid intake and having an inlet in fluid communication with an outlet of the fluid intake, having a fluid mover coupled to a drive shaft, and having a fluid reservoir located downstream of the fluid mover; a gas separator located downstream of the charge pump assembly and having an inlet in fluid communication with an outlet of the charge pump assembly; an inverted shroud coupled at an upper end to the gas separator or to the charge pump assembly and coupled at a lower end to the ESP assembly below the fluid intake; and a production pump assembly located downstream of the gas separator and having an inlet in fluid communication with a liquid phase discharge port of the gas separator.

An electric submersible pump (ESP) assembly. The ESP assembly comprises an electric motor; a seal section; a fluid intake; a charge pump assembly located downstream of the fluid intake and having an inlet in fluid communication with an outlet of the fluid intake, having a fluid mover coupled to a drive shaft, and having a fluid reservoir located downstream of the fluid mover; a gas separator located downstream of the charge pump assembly and having an inlet in fluid communication with an outlet of the charge pump assembly; an inverted shroud coupled at an upper end to the gas separator or to the charge pump assembly and coupled at a lower end to the ESP assembly below the fluid intake; and a production pump assembly located downstream of the gas separator and having an inlet in fluid communication with a liquid phase discharge port of the gas separator.

A submersible pump assembly includes a pump, a motor, and a seal section connected between. A shaft passage in the seal section has an outboard end that is open to the pump intake and an inboard end that is in fluid communication with motor lubricant in the motor. A drive shaft extends axially within the shaft passage. An outboard bearing at the outboard end of the shaft passage receives the shaft to provide radial support. An inboard bearing at the inboard end of the shaft passage receives the shaft to provide radial support. A shaft seal in the shaft passage receives and seals around the shaft. The shaft seal is located between the outboard bearing and the inboard bearing and seals motor lubricant in the shaft passage from well fluid in the shaft passage.

An assembly and a method for lubricating an electric submersible pump assembly disposed in a wellbore are described. The assembly includes a pump to pressurize a wellbore fluid and an electric motor to rotate the pump. The electric motor is lubricated by a dielectric oil. A sensor is coupled to the electric motor to sense a condition of the electric motor and transmit a signal including a value representing the condition. A controller is coupled to the electric motor and the sensor. The controller receives the signal from the sensor, compares the value to a threshold value, determines when the value is greater than the threshold value, and responsive to determining that the value is greater than a threshold value indicating a presence of contaminated dielectric oil, flows a clean dielectric oil from an accumulator to the electric motor to expel the contaminated dielectric oil out of the electric motor.

An electric submersible pump assembly with integral heat exchanger, high speed gas separator, high-speed self-aligning bearings, and dual bearing thrust chamber is described. The described gas separator may be used for operating an electric submersible pump at high speeds as well as over a wide range of speeds and flowrates without replacing downhole equipment.

An electric submersible pump assembly with integral heat exchanger, high speed gas separator, high-speed self-aligning bearings, and dual bearing thrust chamber is described. The described gas separator may be used for operating an electric submersible pump at high speeds as well as over a wide range of speeds and flowrates without replacing downhole equipment.

The application relates to a pump apparatus for pumping liquid, and more particularly to a technique for removing foreign matters contained in the liquid when an impeller catches on the foreign matters. The pump apparatus includes: an impeller (1); an electric motor (7) configured to rotate the impeller (1); an inverter (14) configured to drive the electric motor (7); a current measuring device (15) configured to measure a current supplied to the electric motor (7); and an operation controller (17) configured to instruct the inverter (14) to cause the impeller (1) to perform a foreign-matter removing operation including at least two of: an intermittent operation that intermittently rotates the impeller (1) in a forward direction; a reverse-rotating operation that rotates the impeller (1) in a reverse direction; and a forward and reverse inching operation that rotates the impeller (1) in the reverse direction and the forward direction alternately and repeatedly.

The application relates to a pump apparatus for pumping liquid, and more particularly to a technique for removing foreign matters contained in the liquid when an impeller catches on the foreign matters. The pump apparatus includes: an impeller (1); an electric motor (7) configured to rotate the impeller (1); an inverter (14) configured to drive the electric motor (7); a current measuring device (15) configured to measure a current supplied to the electric motor (7); and an operation controller (17) configured to instruct the inverter (14) to cause the impeller (1) to perform a foreign-matter removing operation including at least two of: an intermittent operation that intermittently rotates the impeller (1) in a forward direction; a reverse-rotating operation that rotates the impeller (1) in a reverse direction; and a forward and reverse inching operation that rotates the impeller (1) in the reverse direction and the forward direction alternately and repeatedly.