Charge pump for electric submersible pump (ESP) assembly with inverted shroud

Patent metadata

Field	Value
Publication number	US-11946472-B2
Application number	US-202117492227-A
Country	US
Kind code	B2
Filing date	Oct 1, 2021
Priority date	Oct 1, 2021
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

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.

First claim

What is claimed is:

1. An electric submersible pump (ESP) assembly, comprising:
an electric motor having a first drive shaft;
a seal section coupled at an upstream end to a downstream end of the electric motor having a second drive shaft coupled to the first drive shaft;
a charge pump assembly disposed downstream of the seal section, wherein the charge pump assembly comprises
a third drive shaft coupled to the second drive shaft,
a first fluid mover mechanically coupled to the third drive shaft and having a fluid inlet and a fluid outlet,
a fluid reservoir concentrically disposed around the third drive shaft and located downstream of the first fluid mover, wherein an inside surface of the fluid reservoir and an outside surface of the third drive shaft define a first annulus that is fluidically coupled to the fluid outlet of the first fluid mover, wherein the third drive shaft is not radially supported within the first annulus, wherein when the separator drive shaft is about 0.6875 inches in diameter, the first annulus has a volume of at least 70 cubic inches and less than 100 cubic inches, when the separator drive shaft is about 0.875 inches in diameter, the first annulus has a volume of at least 85 cubic inches and less than 120 cubic inches, when the separator drive shaft is about 1.0 inches in diameter, the first annulus has a volume of at least 180 cubic inches and less than 250 cubic inches, and when the separator drive shaft is about 1.1875 inches in diameter, the first annulus has a volume of at least 220 cubic inches and less than 300 cubic inches, and
a second fluid mover mechanically coupled to the third drive shaft and having a fluid inlet and a fluid outlet, wherein the second fluid mover is located downstream of the fluid reservoir, and wherein the fluid inlet of the second fluid mover is fluidically coupled to the first annulus;

a gas separator assembly coupled at an upstream end to a downstream end of the charge pump assembly, having a fourth drive shaft coupled directly or indirectly to the third drive shaft and having an inlet in fluid communication with an outlet of the charge pump assembly, having a gas flow path and liquid flow path separator having a gas phase discharge port open to an exterior of the gas separator assembly and a liquid phase discharge port;
an inverted shroud coupled at an uphole end to the gas separator assembly or to the charge pump assembly and coupled at a downhole end to the ESP assembly downhole of the charge pump assembly; and
a production pump assembly coupled at an upstream end to a downstream end of the gas separator assembly and having an inlet in fluid communication with the liquid phase discharge port of the gas flow path and liquid flow path separator.

2. The ESP assembly of claim 1 , wherein a distance between a downstream end of the seal section and the gas phase discharge port of the gas flow path and liquid flow path separator is at least 6 feet and less than 500 feet.

3. The ESP assembly of claim 1 , wherein the fluid reservoir is at least 6 inches long and less than 17 inches long.

4. The ESP assembly of claim 1 , further comprising a spider bearing located within the fluid reservoir that has a central through-hole that surrounds the drive shaft.

5. The ESP assembly of claim 4 , wherein the fluid reservoir is at least 17 inches long and less than 34 inches long.

6. The ESP assembly of claim 1 , wherein the charge pump assembly further comprises a housing, wherein the inside surface of the fluid reservoir is provided by an inside surface of the housing, wherein the first fluid mover and the second fluid mover are located within the housing.

7. The ESP assembly of claim 6 , wherein the first fluid mover comprises at least one centrifugal pump stage, wherein the at least one centrifugal pump stage comprises an impeller mechanically coupled to the third drive shaft and a diffuser retained by the housing.

8. The ESP assembly of claim 1 , wherein the first fluid mover is an auger mechanically coupled to the third drive shaft.

9. The ESP assembly of claim 1 , further comprising a second fluid reservoir concentrically disposed around the third drive shaft and located downstream of the second fluid mover, wherein an inside surface of the second fluid reservoir and an outside surface of the third drive shaft define a second annulus that is fluidically coupled to the fluid outlet of the second fluid mover.

10. A method of lifting liquid in a wellbore, comprising:
running an electric submersible pump (ESP) assembly into a wellbore, wherein the ESP assembly comprises
an electric motor having a first drive shaft,
a seal section coupled at an upstream end to a downstream end of the electric motor having a second drive shaft coupled to the first drive shaft,
a charge pump assembly disposed downstream of the seal section, wherein the charge pump assembly comprises
a third drive shaft coupled to the second drive shaft,
a first fluid mover mechanically coupled to the third drive shaft and having a fluid inlet and a fluid outlet,
a fluid reservoir concentrically disposed around the third drive shaft and located downstream of the first fluid mover, wherein an inside surface of the fluid reservoir and an outside surface of the third drive shaft define a first annulus that is fluidically coupled to the fluid outlet of the first fluid mover, wherein the third drive shaft is not radially supported within the first annulus, wherein when the separator drive shaft is about 0.6875 inches in diameter, the first annulus has a volume of at least 70 cubic inches and less than 100 cubic inches, when the separator drive shaft is about 0.875 inches in diameter, the first annulus has a volume of at least 85 cubic inches and less than 120 cubic inches, when the separator drive shaft is about 1.0 inches in diameter, the first annulus has a volume of at least 180 cubic inches and less than 250 cubic inches, and when the separator drive shaft is about 1.1875 inches in diameter, the first annulus has a volume of at least 220 cubic inches and less than 300 cubic inches, and
a second fluid mover mechanically coupled to the third drive shaft and having a fluid inlet and a fluid outlet, wherein the second fluid mover is located downstream of the fluid reservoir, and wherein the fluid inlet of the second fluid mover is fluidically coupled to the first annulus,

a gas separator assembly coupled at an upstream end to a downstream end of the charge pump assembly, having a fourth drive shaft coupled directly or indirectly to the third drive shaft and having an inlet in fluid communication with an outlet of the charge pump assembly, having a gas flow path and liquid flow path separator having a gas phase discharge port open to an exterior of the gas separator assembly and a liquid phase discharge port,
an inverted shroud coupled at an uphole end to the gas separator assembly or to the charge pump assembly and coupled at a downhole end to the ESP assembly downhole of the charge pump assembly, and
a production pump assembly coupled at an upstream end to a downstream end of the gas separator assembly and having an inlet in fluid communication with the liquid phase discharge port of the gas flow path and liquid flow path separator;

turning the third drive shaft of the charge pump assembly by the electric motor;
drawing reservoir fluid from the wellbore into the charge pump assembly by the first fluid mover;
moving the reservoir fluid downstream by the first fluid mover within the charge pump assembly;
filling the first annulus within the charge pump assembly with the reservoir fluid;
flowing the reservoir fluid from the first annulus to the fluid inlet of the gas separator assembly;
dischargi

Assignees

• Halliburton Energy Services Inc

Inventors

• Sheth Ketankumar Kantilal
• Brown Donn J
• Mathes Randy Louis

Classifications

• F04D13/08 Primary

  for submerged use · CPC title

• E21B43/00

  Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells (applicable only to water E03B) · CPC title

• E21B43/128 Primary

  Adaptation of pump systems with down-hole electric drives · CPC title

• E21B43/38

  in the well · CPC title

• F04D3/02

  of screw type · CPC title