WO2024172682A1

WO2024172682A1 - Displacement unit for an electric submersible pump

Info

Publication number: WO2024172682A1
Application number: PCT/RU2023/000036
Authority: WO
Inventors: Andrey Igorevich SHOSTAK; Vladimir Vladimirovich CHUGUNOV; Nikita Andreevich FISIVSKI; Victoria Vladislavovna IVANYKINA
Original assignee: Schlumberger Canada Ltd; Services Petroliers Schlumberger SA; Schlumberger Technology BV; Schlumberger Technology Corp
Current assignee: Schlumberger Canada Ltd; Services Petroliers Schlumberger SA; Schlumberger Technology BV; Schlumberger Technology Corp
Priority date: 2023-02-16
Filing date: 2023-02-16
Publication date: 2024-08-22
Anticipated expiration: 2025-08-16

Abstract

A displacement unit. The displacement unit may include a body, a head shaft, a base shaft, a middle shaft, and radial bearings. The body may include a head and a base. The head shaft may extend through the head of the body. The base shaft may extend through the base of the body. The middle shaft may be coupled to the head shaft via a first flexible coupling and coupled to the base shaft via a second flexible coupling. The radial bearings may be disposed within body to support at least one of the head shaft, the middle shaft, or the base shaft.

Description

DISPLACEMENT UNIT FORAN ELECTRIC SUBMERSIBLE PUMP

BACKGROUND

[0001] Various types of artificial lift equipment and methods are available, for example, electric submersible pumps (ESPs). An ESP includes multiple centrifugal pump stages mounted in series, each stage including a rotating impeller and a stationary diffuser mounted on a shaft, which is coupled to a motor. In use, the motor rotates the shaft, which in turn rotates the impellers within the diffusers. Well fluid flows into the lowest stage and passes through the first impeller, which centrifuges the fluid radially outward such that the fluid gains energy in the form of velocity. Upon exiting the impeller, the fluid flows into the associated diffuser, where fluid velocity is converted to pressure. As the fluid moves through the pump stages, the fluid incrementally gains pressure until the fluid has sufficient energy to travel to the well surface.

SUMMARY

[0002] A displacement unit according to one or more embodiments of the present disclosure includes a body, a head shaft, a base shaft, a middle shaft, and radial bearings. The body includes a head and a base. The head shaft extends through the head of the body. The base shaft extends through the base of the body. The middle shaft is coupled to the head shaft via a first flexible coupling and coupled to the base shaft via a second flexible coupling. The radial bearings are disposed within body to support at least one of the head shaft, the middle shaft, or the base shaft.

[0003] A electric submersible pump (“ESP”) according to one or more embodiments of the present disclosure includes a motor, a protector, and a displacement unit. The motor includes a motor shaft. The protector includes a protector shaft. The displacement unit is operably coupling the motor to the protector and includes a body, a middle shaft, and radial bearings. The body includes a head and a base. The protector shaft extending through the head of the body and the motor shaft extending through the base of the body. The middle shaft is shaft coupled to the protector shaft via a first flexible coupling and coupled to the motor shaft via a second flexible coupling. The

SUBSTITUTE SHEET (RULE 26) radial bearings are disposed within body to support at least one of the motor shaft, the middle shaft, or the protector shaft.

[0004] A method of producing hydrocarbons according to one or more embodiments of the present disclosure includes coupling a base of a quick disconnect system to a first subsystem of the ESP. The method further includes disposing an ESP within a wellbore. The method also includes transferring torque from a motor of the ESP to a displacement unit of the ESP. The method further transferring torque from the displacement unit to a protector of the ESP.

BRIEF DESCRIPTION OF THE FIGURES

[0005] Certain embodiments, features, aspects, and advantages of the disclosure will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. In accordance with standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or reduced for clarity of discussion. It should be understood that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various technologies described herein.

[0006] FIG. 1 is a schematic of an electric submersible pump (ESP) system, according to an embodiment of the disclosure;

[0007] FIG. 2 is a partial, cross-sectional view of an ESP, according to an embodiment of the disclosure;

[0008] FIG. 3 is a cross-sectional view of a displacement unit, according to an embodiment of the disclosure; and

[0009] FIG. 4 is a cross-sectional view of a flexible coupling of FIG. 3.

DETAILED DESCRIPTION

[0010] In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the disclosure. These

SUBSTITUTE SHEET (RULE 26) are, of course, merely examples and are not intended to be limiting. In addition, the disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. 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 are possible. This description is not to be taken in a limiting sense, but rather made merely for the purpose of describing general principles of the implementations. The scope of the described implementations should be ascertained with reference to the issued claims.

[0011] As used herein, the terms “connect”, “connection”, “connected”, “in connection with”, and “connecting” are used to mean “in direct connection with” or “in connection with via one or more elements”; and the term “set” is used to mean “one element” or “more than one element”. Further, the terms “couple”, “coupling”, “coupled”, “coupled together”, and “coupled with” are used to mean “directly coupled together” or “coupled together via one or more elements”. As used herein, the terms "up" and "down"; "upper" and "lower"; "top" and "bottom"; and other like terms indicating relative positions to a given point or element are utilized to more clearly describe some elements. Commonly, these terms relate to a reference point at the surface from which drilling operations are initiated as being the top point and the total depth being the lowest point, wherein the well (e.g., wellbore, borehole) is vertical, horizontal or slanted relative to the surface.

[0012] Various types of artificial lift equipment and methods are available, for example, electric submersible pumps (ESP). As shown in the example embodiment of Figure 1, an ESP 110 may include a motor 116, a protector 115, a displacement unit 118, a pump 112, a pump intake 114, and one or more cables 111, which can include an electric power cable. The motor 116 can be powered and controlled by a surface power supply and controller, respectively, via the cables 111. In some configurations, the ESP 110 also includes gas handling features 113 and/or one or more sensors 117 (e.g., for temperature, pressure, current leakage, vibration, etc.). As shown, the well may include one or more well sensors 120.

SUBSTITUTE SHEET (RULE 26) [0013] The pump 112 includes multiple centrifugal pump stages mounted in series within a housing 230, as shown in Figure 2A. Each stage includes a rotating impeller 210 and a stationary diffuser 220. One or more spacers 204 can be disposed axially between sequential impellers 210. A shaft 202 extends through the pump 112 (e.g., through central hubs or bores or the impellers 210 and diffusers 220) and is operatively coupled to the motor 116. The shaft 202 can be coupled to the protector 115 (e.g., a shaft of the protector), which in turn can be coupled to the motor 116 (e.g., a shaft of the motor) via a displacement unit 118 (e.g., a shaft of the displacement unit). The impellers 210 are rotationally coupled, e.g., keyed, to the shaft 202. The diffusers 220 are coupled, e.g., rotationally fixed, to the housing 230. In use, the motor 116 causes rotation of the shaft 202 (for example, by rotating the protector 115 shaft, which rotates the pump shaft 202), which in turn rotates the impellers 210 relative to and within the stationary diffusers 220.

[0014] In use, well fluid flows into the first (lowest) stage of the ESP 110 and passes through an impeller 210, which centrifuges the fluid radially outward such that the fluid gains energy in the form of velocity. Upon exiting the impeller 210, the fluid makes a sharp turn to enter a diffuser 220, where the fluid’s velocity is converted to pressure. The fluid then enters the next impeller 210 and diffuser 220 stage to repeat the process. As the fluid passes through the pump stages, the fluid incrementally gains pressure until the fluid has sufficient energy to travel to the well surface.

[00015] Turning now to FIG. 3, FIG. 3 is a displacement unit 300 that transmits torque from the motor to the protector. As shown in FIG. 3, the displacement unit 300 includes a body that includes a head 302, radial bearings 304, nipples 306, multiple shafts 308, 310, 312 extending through the displacement unit 300 and coupled via one or more flexible couplings 314, and a base 316. As shown in FIG. 3, each shaft, e.g., the head shaft 308, the middle shaft 310, or the base shaft 312, is coupled to the adjacent shaft via the flexible coupling. The flexible couplings 314 allow adjacent shafts to move eccentrically relative to one another while still transferring torque to the adjacent shaft. Further, one or more of the shafts may be supported via the radial bearings 304 to limit eccentric movement of the shaft relative to the head 302 or the base.

[0016] The base 316 includes an upper flange 318 eccentrically positioned relative to the base 316 such that a lower flange 320, e.g., a motor flange, is coupled to

SUBSTITUTE SHEET (RULE 26) the base 316 at an eccentric position relative to the base 316. In other embodiments, the upper flange may be replaced by a thread profile that is positioned such that a mating component is at an eccentric position relative to the longitudinal axis of the base 316. This allows a motor to be coupled to a protector eccentrically via the displacement unit 300, instead of the conventional concentric arrangement of the protector and the motor. The eccentric arrangement of the motor and protector due to the displacement unit 300 reduces the overall outer diameter of the motor and protector assembly, allowing an ESP to be used in casings having a reduced diameter.

[0017] Turning now to FIG. 4, FIG. 4 is a flexible coupling 314 that allows for radial displacement of one shaft 308 relative to another shaft 310 while transferring torque between the shafts. The flexible coupling 314 includes a first body 500 coupled to a second body 502 via fasteners 504 or similar means. A lamination pack 506 is disposed between the first body 500 and the second body 502 and allows for angular displacement between the shafts 308, 310 disposed within the flexible coupling 314 while transferring torque between the shafts 308, 310. In one or more embodiments, each shaft 308, 310 is press-fit onto the flexible coupling 314 and is prevented from rotating relative to the respective body 500, 502 of the flexible coupling 314 via pins positioned in aligning grooves 508 formed in the shafts 308, 310 and the bodies 500, 502. In other embodiments, the bodies 500, 502 may include splines that extend into the first shaft 308 and the second shaft 310, respectively.

[0018] Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately,” “about,” “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and/or within less than 0.01% of the stated amount. As another example, in certain embodiments, the terms “generally parallel” and “substantially parallel” or “generally perpendicular” and “substantially perpendicular” refer to a value, amount, or characteristic that departs from exactly parallel or perpendicular, respectively, by less than or equal to 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree, or 0.1 degree.

SUBSTITUTE SHEET (RULE 26) [0019] Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments described may be made and still fall within the scope of the disclosure. It should be understood that various features and aspects of the disclosed embodiments can be combined with, or substituted for, one another in order to form varying modes of the embodiments of the disclosure. Thus, it is intended that the scope of the disclosure herein should not be limited by the particular embodiments described above.

SUBSTITUTE SHEET (RULE 26)

Claims

CLAIMS What is claimed is:

1. A displacement unit comprising: a body comprising a head and a base; a head shaft extending through the head of the body; a base shaft extending through the base of the body a middle shaft coupled to the head shaft via a first flexible coupling and coupled to the base shaft via a second flexible coupling; and radial bearings disposed within body to support at least one of the head shaft, the middle shaft, or the base shaft.

2. The displacement unit of claim 1, wherein the base comprises a flange eccentrically positioned relative to the base.

3. The displacement unit of claim 1, wherein the first flexible coupling comprises: a first body coupled to the head shaft; a second body coupled to the middle shaft and to the first body; and a lamination pack disposed between the first body and the second body that allows for angular displacement between the head shaft and the middle shaft while transferring torque between the head shaft and the middle shaft.

4. The displacement unit of claim 3, further comprising pins disposed in aligning grooves of the head shaft and the first body to prevent relative rotation between the head shaft and the first body.

5. The displacement unit of claim 3, further comprising pins disposed in aligning grooves of the base shaft and the second body to prevent relative rotation between the head shaft and the first body.

SUBSTITUTE SHEET (RULE 26)

6. The displacement unit of claim 3, wherein the first body comprises splines that extend into grooves formed in the first body to prevent relative rotation between the head shaft and the first body.

7. The displacement unit of claim 3, wherein the second body comprises splines that extend into grooves formed in the second body to prevent relative rotation between the middle shaft and the second body.

8. An electric submersible pump (“ESP”) comprising; a motor comprising a motor shaft; and a protector comprising a protector shaft; a displacement unit operably coupling the motor to the protector and comprising: a body comprising a head and a base, the protector shaft extending through the head of the body and the motor shaft extending through the base of the body; a middle shaft coupled to the protector shaft via a first flexible coupling and coupled to the motor shaft via a second flexible coupling; and radial bearings disposed within body to support at least one of the motor shaft, the middle shaft, or the protector shaft.

9. The ESP of claim 8, wherein the base comprises a flange eccentrically positioned relative to the base.

10. The ESP of claim 8, wherein the first flexible coupling comprises: a first body coupled to the head shaft; a second body coupled to the middle shaft and to the first body; and

SUBSTITUTE SHEET (RULE 26) a lamination pack disposed between the first body and the second body that allows for angular displacement between the head shaft and the middle shaft while transferring torque between the head shaft and the middle shaft.

11. The ESP of claim 10, further comprising pins disposed in aligning grooves of the head shaft and the first body to prevent relative rotation between the head shaft and the first body.

12. The ESP of claim 10, further comprising pins disposed in aligning grooves of the base shaft and the second body to prevent relative rotation between the head shaft and the first body.

13. The ESP of claim 10, wherein the first body comprises splines that extend into grooves formed in the first body to prevent relative rotation between the head shaft and the first body.

14. The ESP of claim 10, wherein the second body comprises splines that extend into grooves formed in the second body to prevent relative rotation between the middle shaft and the second body.

15. A method of producing hydrocarbons comprising: disposing an ESP within a wellbore; and transferring torque from a motor of the ESP to a displacement unit of the ESP; and transferring torque from the displacement unit to a protector of the ESP.

16. The method of claim 15, wherein transferring torque from the motor of the

ESP to a displacement unit of the ESP comprises transferring torque though a motor shaft of the motor to middle shaft of the displacement unit via a flexible coupling.

SUBSTITUTE SHEET (RULE 26)

17. The method of claim 16, wherein transferring torque though a motor shaft of the motor to middle shaft of the displacement unit via the flexible coupling comprises: coupling the motor shaft to a first body of the flexible coupling; coupling the middle shaft to a second body of the flexible coupling; and coupling the first body to the second body such that a lamination pack is disposed between the first body and the second body that allows for angular displacement between the motor shaft and the middle shaft while transferring torque between the motor shaft and the middle shaft.

18. The method of claim 15, wherein transferring torque from the displacement unit of the ESP to the protector of the ESP comprises transferring torque though middle shaft of the displacement unit to a protector shaft of the protector via a flexible coupling.

19. The method of claim 18, wherein transferring torque though middle shaft of the displacement unit to a protector shaft of the protector via a flexible coupling comprises: coupling the middle shaft to a first body of the flexible coupling; coupling the protector shaft to a second body of the flexible coupling; and coupling the first body to the second body such that a lamination pack is disposed between the first body and the second body that allows for angular displacement between the middle shaft and the protector shaft while transferring torque between the middle shaft and the protector shaft.

SUBSTITUTE SHEET (RULE 26)