Breather tube for labyrinth seal chamber
AssigneeSaudi Arabian Oil Company
InventorsChristopher Wrighton, Sakethraman Mahalingam
Life of this patent
Estimating the term…
Abstract
An electrical submersible pumping assembly includes a motor, a pump connected to the motor by a shaft, and a labyrinth type seal section between the motor and pump. Hydrostatic pressure is communicated between the motor and pump across the seal section and through a breather tube in the seal section that is configured to restrict fluid communication from the pump to the motor. A U-shaped bend is provided in the breather tube to increase its effective length. Optionally, a number of recycle loops are formed on the breather tube similar to a Tesla valve. In an alternative, the shaft includes a helical flight that directs fluid to a mechanical shaft seal between pump and seal section.
Claims18
An electrical submersible pumping system (“ESP”) that is selectively disposed in a wellbore, the ESP comprising:
- a motor;
- a shaft having an end attached to the motor;
- a pump attached to an end of the shaft distal from the motor;
- and
- a seal section disposed between the motor and the pump comprising,
- a breather tube having,
- an uphole end that is in pressure communication to ambient hydrostatic pressure,
- a downhole end distal from the uphole end and that is in pressure communication with the motor, and
- a mid-portion having an undulating contour that comprises a recycle loop mounted to the breather tube, the recycle loop having a curved mid-section and upper and lower ends that intersect the breather tube at spaced apart locations along a length of the breather tube to define a valvular conduit.
An electrical submersible pumping system (“ESP”) selectively disposed in a wellbore, the ESP comprising:
- a motor;
- a pump uphole of the motor;
- a shaft having an end attached the motor and an opposing end attached to the pump;
- and
- a seal section disposed between the motor and the pump having a labyrinth chamber with a flow path that restricts fluid communication, the flow path extending through a breather tube with a diameter that creases with distance downhole.
A method of operating an electrical submersible pumping system (“ESP”) comprising:
- providing electricity to the ESP is disposed in a wellbore, to energize a motor in the ESP to rotate a shaft connected between the motor and a pump, so that fluid in the wellbore is pressurized by the pump;
- equalizing pressure of dielectric fluid inside the motor with hydrostatic pressure in the wellbore by communicating pressure of the wellbore to the dielectric fluid through a communicating fluid that is flowable along a pathway that intersects a seal disposed between the motor and pump;
- and
- blocking fluid in the wellbore from communicating to dielectric fluid inside the motor by diverting a portion of the communicating fluid flowing towards the motor and reintroducing the portion into the pathway in a direction pointing away from the motor.
Dependencies are inferred from the claim text.