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CA-3041312-C - GAS PURGING FOR ELECTRIC SUBMERSIBLE PUMPING SYSTEM

CA3041312CCA 3041312 CCA3041312 CCA 3041312CCA-3041312-C

Abstract

A technique facilitates removal of gas from a gas-sensitive region in an electric submersible pumping system. A gas purging system is integrated into the electric submersible pumping system. During operation of the electric submersible pumping system, the gas purging system also is operated to move gas away from the gas-sensitive region, e.g. a thrust bearing region, and to a collection region or other suitable region. In some embodiments, the gas which accumulates in a collection region may be discharged to a region external of the electric submersible pumping system.

Inventors

  • Arthur I. Watson
  • Grant T. Harris

Assignees

  • SCHLUMBERGER CANADA LIMITED

Dates

Publication Date
20260505
Application Date
20171023
Priority Date
20161023

Claims (7)

  1. 85234863 CLAIMS: 1. A system for use in a well, comprising: an electric submersible pumping system having a submersible motor, a motor protector, a submersible pump powered by the submersible motor, a gas-sensitive section positioned in the motor protector and comprising a thrust bearing and a thrust runner which rotate relative to each other when the shaft is rotated, and a gas purging system to remove gas from the gas-sensitive section, the gas purging system comprising: a shaft; a pumping feature driven by rotation of the shaft to draw gas away from a radially inward region of the gas-sensitive section; and a sump chamber positioned to receive the gas from the pumping feature via a diffuser disposed radially through a shaft tube positioned around the shaft.
  2. 2. The system as recited in claim 1, wherein the pumping feature comprises a helical groove formed along the shaft.
  3. 3. The system as recited in claim 1, wherein the electric submersible pumping system is a generally horizontal electric submersible pumping system.
  4. 4. The system as recited in claim 1, wherein the gas purging system comprises a body section disposed between the sump chamber in the thrust runner, the body section having a plurality of passages therethrough, the passages being oriented to move gas away from the thrust runner and to move motor oil to the thrust runner as the shaft is rotated.
  5. 5. The system as recited in claim 4, wherein the gas purging system comprises a plurality of gas discharge passages routed from the sump chamber to a relief valve to discharge gas from the sump chamber.
  6. 6. The system as recited in claim 5, wherein the gas purging system comprises a plurality of baffles arranged in the sump chamber to facilitate separation of gas and motor oil in the sump chamber.
  7. 7. The system as recited in claim 5, wherein the gas purging system comprises a filter positioned to filter motor oil from gas as a mixed gas and motor oil fluid flows to the plurality of gas discharge passages. 14 Date Re9ue/Date Recieved 2024-02-05 85234863 8. The system as recited in claim 5, wherein the gas purging system comprises a weighted disc which automatically orients to block flow of fluid into lower gas discharge passages of the plurality of gas discharge passages and to allow flow of fluid into upper gas discharge passages of the plurality of gas discharge passages when the electric submersible pumping system is generally horizontal. 9. A system, comprising: an electric submersible pumping system having a submersible motor, a motor protector, a submersible pump powered by the submersible motor via a shaft, a gas-sensitive section positioned in the motor protector and comprising a thrust bearing section having a thrust bearing and a thrust runner, and a gas purging system to remove gas from the gas-sensitive section, the gas purging system comprising: a sump chamber; and a body section disposed between the sump chamber and the thrust runner, the body section having a plurality of passages therethrough, the passages being oriented to move gas away from the thrust runner and to move motor oil to the thrust runner as the shaft is rotated. 10. The system as recited in claim 9, wherein the gas purging system further comprises a pumping feature driven by rotation of the shaft to draw gas away from a radially inward region of the thrust bearing section, the sump chamber being positioned to receive the gas from the pumping feature via a diffuser disposed radially through a shaft tube positioned around the shaft. 11. The system as recited in claim 9, wherein the gas purging system further comprises a centrifugal agitator mounted on the shaft along the sump chamber to facilitate separation of gas from motor oil. 12. The system as recited in claim 10, wherein the pumping feature comprises a helical groove formed along the shaft. 13. The system as recited in claim 10, wherein the gas purging system comprises a plurality of gas discharge passages routed from the sump chamber to a relief valve to discharge gas from the sump chamber; and a plurality of baffles arranged in the sump chamber to facilitate separation of gas and motor oil in the sump chamber. 14. A method of removing gas during a well pumping operation, comprising: Date Re9ue/Date Recieved 2024-02-05 85234863 providing an electric submersible pumping system with a submersible pump driven by a submersible motor containing a motor oil; resisting thrust of the submersible pump with a thrust bearing section having a thrust bearing and a corresponding thrust runner mounted on a rotatable shaft of the electric submersible pumping system; using a gas purging system to remove gas which collects along a radially inward region of the electric submersible pumping system when the gas is liberated from the motor oil; and pumping the gas, which is liberated from the motor oil, to a sump chamber. 15. The method as recited in claim 14, wherein pumping gas comprises using a helical groove along the shaft to move the gas along the shaft from the thrust bearing section to the sump chamber during rotation of the shaft. 16. The method as recited in claim 14, further comprising using baffles in the sump chamber to improve separation of gas from the motor oil. 17. The method as recited in claim 14, further comprising orienting a plurality of passages through a body section between the sump chamber and the corresponding thrust runner; and orienting the electric submersible pumping system substantially horizontally to enable a pumping action through the plurality of passages to remove gas from the thrust bearing section. 18. The method as recited in claim 14, further comprising locating a plurality of gas discharge passages between the sump chamber and a relief valve to facilitate discharge of gas from the sump chamber. 16 Date Re9ue/Date Recieved 2024-02-05

Description

WO 2018/076000 PCT/0S2017/057777 PATENT APPLICATION GAS PURGING FOR ELECTRIC SUBMERSIBLE PUMPING SYSTEM CROSS-REFERENCE TO RELATED APPLICATION [0001] The present document is based on and claims priority to US Provisional Application Serial No.: 62/411,647, filed October 23, 2016, which is incorporated herein by reference in its entirety. BACKGROUND [0002] In various well applications, a wellbore is drilled into a hydrocarbon bearing reservoir and then a pumping system may be deployed downhole. The pumping system is operated to pump oil and/or other fluids to the surface for collection. The pumping system may comprise an electric submersible pumping system having a submersible pump powered by a submersible electric motor. Thrust from the submersible pump is resisted by a thrust bearing working in cooperation with a thrust runner. In some applications, excess gas builds up between the thrust bearing and the thrust runner. The excess gas may cause wear and sometimes failure of the thrust bearing. SUMMARY [0003] In general, the present disclosure provides a system and method for removing gas from a gas-sensitive region, e.g. from a thrust bearing section, in an electric 1 WO 2018/076000 PCT/0S2017/057777 submersible pumping system. A gas purging system is integrated into the electric submersible pumping system. During operation of the electric submersible pumping system, the gas purging system also is operated to move gas away from the gas-sensitive region and to a collection region or other appropriate region. In some embodiments, the gas which accumulates in a collection region may be discharged to a region external of the electric submersible pumping system. BRIEF DESCRIPTION OF THE DRAWINGS [0005] Certain embodiments will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying figures illustrate various implementations described herein and are not meant to limit the scope of various technologies described herein, and: [0006] Figure I is a schematic illustration of an example of a well system having an electric submersible pumping system deployed in a lateral section, e.g. a horizontal section, of a borehole, according to an embodiment of the disclosure; [0007] Figure 2 is a cross-sectional view of a portion of the electric submersible pumping system having a thrust bearing section working in cooperation with a gas purging system, according to an embodiment of the disclosure; [0008] Figure 3 is a cross-sectional view of another portion of the gas purging system, according to an embodiment of the disclosure; [0009] Figure 4 is a cross-sectional view of another example of the gas purging system, according to an embodiment of the disclosure; [0010] Figure 5 is a cross-sectional view of another example of the gas purging system, according to an embodiment of the disclosure; and 2 WO 2018/076000 PCT/0S2017/057777 [0011] Figure 6 is a cross-sectional view of another example of the gas purging system, according to an embodiment of the disclosure. DETAILED DESCRIPTION [0012] In the following description, numerous details are set forth to provide an understanding of some illustrative embodiments of the present disclosure. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible. [0013] The disclosure herein generally relates to a system and method for removing gas from a region within an electric submersible pumping system. For example, gas may be removed from a thrust bearing section of the pumping system. A gas purging system may be integrated into the electric submersible pumping system to effectively remove gas from the region, e.g. thrust bearing section, when the electric submersible pumping system is in a horizontal orientation or various other orientations. For example, the gas purging system works well for removing gas from the thrust bearing section of a horizontal electric submersible pumping system disposed in a lateral wellbore. [0014] During operation of the electric submersible pumping system, a submersible pump is rotated by a submersible motor via a shaft. According to an embodiment, the gas purging system also is operated via rotation of the shaft to move gas away from the thrust bearing section and to a collection region or other suitable region. The gas purging system may comprise one or more features which operate to remove gas from the thrust bearing section and to transfer the gas to the collection region, e.g. to a sump chamber. In some embodiments, gas which accumulates in the collection region may be discharged to a region external of the electric submersible pumping system. 3 WO 2018/076000 PCT/0S2017/057777 [0015] According to an embodiment, an electric submersible pumping system comprises a th