Esp protector bag support and gas purging protector for low angle application

Abstract

An electric submersible pump (ESP). The ESP may comprise a bag frame comprising an upper bag frame and a lower bag frame. The ESP may comprise a bag. The ESP may comprise a housing. The ESP may comprise a shaft tube. The ESP may comprise a clamp. The ESP may comprise a bag support with a lower bag support and an upper bag support. The bag support may support an external surface of the bag that is uncovered by the housing, the bag frame, the shaft tube, and the clamps. The lower bag support may comprise a single, complete ring that supports the bag from the clamp to the housing.

Description

IS22.0592ESP PROTECTOR BAG SUPPORT AND GAS PURGING PROTECTOR FOR LOW ANGLE APPLICATIONCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the priority benefit of Indian Provisional Application No.202411028345 filed April 5, 2024, the entire contents of which are incorporated by reference in their entirety.BACKGROUNDField

[0002] The present disclosure generally relates to electric submersible pumps (ESPs).SUMMARY

[0003] Electric submersible pump (ESP) protectors commonly employ redundant layers of compensation for motor oil thermal expansion and contraction, each layer comprising one or two bags for volume compensation, a shaft seal, and a relief valve to discharge excess oil during initial thermal expansion. Relief valves are prone to leakage in well fluids containing sludge or solids. The sealing force in relief valves is proportional to the cracking pressure, so recent efforts to improve reliability involve increasing the cracking pressure, which the bag must withstand. Recent innovations in hydraulic logic have also increased the number of relief valves acting on a single bag. The added pressure differential on a bag can cause the elastomer to creep and fail. The current application comprises methods and devices for fully supporting the outer surface of a bag to withstand significantly higher pressure differential in the same way that a vehicle tire and rim support an innertube against much higher pressure than the innertube alone could withstand.

[0004] The current disclosure comprises features and methods for purging gas from an ESP protector when it is installed near horizontal in an application where the rotational orientation of the ESP can be controlled, such as in a skid installed on the seabed. In the past, this has been done by timing the threads to orient certain passages and relief valves on the upper side of the ESP to vent gas from chambers below the component. Features of this application include inversion of protector bags to orient the larger end toward the head and thereby reduce the gas trap at the upper neck, circles of vent hole in threaded parts to vent gas with random rotational orientation, andIS22.0592installation of relief valves in a bolted mounting ring that can be indexed at assembly to position the relief valve on the upper side where it can vent gas.

[0005] This application relates to an electric submersible pump (ESP) comprising a housing enclosing the ESP, a bag frame comprising an upper bag frame and a lower bag frame, and a bag supported by the bag frame. The ESP may include a shaft tube extending through the housing and bag frame, a clamp configured to secure the bag to the bag frame, and a bag support comprising a lower bag support and an upper bag support. The bag support may support an external surface of the bag that is not covered by the housing, the bag frame, the shaft tube, and / or the clamp, wherein the lower bag support comprises a complete ring that supports the bag from the clamp to the housing.

[0006] In some embodiments, the upper bag support may comprise an inboard portion and an outboard portion, each portion comprising a complete ring. The inboard portion of the upper bag support may support the bag from the clamp to the housing. The outboard portion of the upper bag support may envelop the bag clamp and comprise a recess configured to accommodate the clamp buckle. The bag support may include at least one radial, one axial, or one circumferential passage for fluid communication, through the housing, to the chamber above the bag or to one or more ports. The bag support may be fixed against rotation and vibration relative to the housing by friction of an O-ring positioned between the bag support and the housing. The bag support may be constructed of fine metal mesh to prevent extrusion or creep of the elastomer bag based on pressure differential. The bag support may comprise one or more holes configured to permit free flow of fluids or solids into and out of the space around the bag as the bag contracts and expands. The bag support may be divided into segments of a circle that join together to form a complete circle, enabling radial assembly over the bag or bag frame. The bag support may be retained from moving upward, downward, or rotationally by trapping an inward projection between one or more neighboring parts.

[0007] This application also includes a bag support for an electric submersible pump (ESP) comprising a lower bag support comprising a single, complete ring that supports the bag from the clamp to the housing, and an upper bag support comprising an inboard portion and an outboard portion, each portion comprising a complete ring. The inboard portion of the upper bag support may be configured to support the bag from the clamp to the housing. The outboard portion of the upper bag support may envelop the bag clamp and include a recess to accommodate a clampIS22.0592buckle. The bag support may include at least one radial passage, axial passage, or circumferential passage for fluid communication, via the housing, to the chamber above the bag or to ports. The bag support may comprise one or more holes configured to permit free flow of fluids or solids into and out of the space around the bag as the bag contracts and expands.

[0008] In other embodiments, the bag support may comprise a fine metal mesh to prevent extrusion or creep of the elastomer bag due to pressure differential. The bag support may be retained from moving upward, downward, or rotationally by trapping an inward projection between one or more neighboring parts. The lower bag support may be fixed against rotation and vibration relative to a lower body by means of friction of an O-ring squeezed between the lower bag support and the lower body. The lower body may be configured to support one or more inner bellows or one or more annular metal bellows. The bag support may include small gaps between the support and the housing to permit free flow of fluids or solids. The bag support may be divided into one or more segments of a circle that join together to form a complete circle, enabling radial assembly over the bag or bag frame. The outboard upper bag support may be joined to the inboard upper bag support with one or more pins, threading, clips, wire, expanding fasteners, interference fit, crimping, or swaging. The lower bag support may comprise a portion smaller in internal diameter than the lower bag frame outer diameter, wherein the portion smaller in internal diameter is trapped between the lower bag frame and the lower body or the lower bag frame and the relief valve mounting ring. The upper bag support may comprise a portion smaller in internal diameter than the upper bag frame outer diameter, wherein the portion smaller in diameter is trapped between the upper bag frame and the upper body or the upper bag frame and a retainer ring.BRIEF DESCRIPTION OF THE FIGURES

[0009] 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. 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.

[0010] Figure 1 shows a schematic of an ESP according to some embodiments.

[0011] Figure 2 shows an elastomer bag according to some embodiments.

[0012] Figure 3 shows an ESP protector according to some embodiments.IS22.0592

[0013] Figure 4 shows an ESP bag according to some embodiments.

[0014] Figure 5 shows another ESP bag according to some embodiments.

[0015] Figure 6 shows a Gas Purging System (GPS) for an ESP according to some embodiments.

[0016] Figure 7 shows another GSP for an ESP bag according to some embodiments.

[0017] Figure 8 shows a low angle system according to some embodiments.

[0018] Figure 9 shows yet another ESP bag according to some embodiments.

[0019] Figure 10 shows an ESP with metal bellows according to some embodiments.

[0020] Figure 11 shows another ESP with metal bellows according to some embodiments.

[0021] Figure 12 shows yet another ESP bag according to some embodiments.DETAILED DESCRIPTION

[0022] 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 are, of course, merely examples and are not intended to be limiting. 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.

[0023] Turning to FIG. 1, elastomer bags may be utilized in electric submersible pump (ESP) protectors (e.g., seal sections) for accommodating thermal expansion and contraction of the motor oil during thermal cycles. Elastomer bags are designed to be flexible and durable, allowing them to accommodate the thermal expansion and contraction of motor oil during the varying temperature cycles experienced in well operations. These bags may be made from high-performance elastomers that can withstand harsh well conditions, including exposure to aggressive chemicals and high temperatures. The design of the elastomer bags may ensure that they canIS22.0592expand and contract without losing their structural integrity, providing reliable performance over extended periods.

[0024] One or more relief valves may be provided to discharge excess motor oil once the bag has expanded to its maximum capacity. The one or more relief valves may open at a predetermined pressure to discharge excess motor oil to maintain pressure balance within the bag and ESP system. The one or more relief valves may be used for maintaining the pressure balance within the ESP protector, preventing overpressure conditions that could damage the bag or other components. The one or more relief valves may include features such as adjustable opening pressures and enhanced sealing mechanisms to improve reliability and performance in various well conditions.

[0025] Relief valve opening pressure subjects the bag to a pressure differential from inside to outside the bag. This pressure differential is a useful factor in the design of elastomer bags, as it determines the stress and strain experienced by the bag during operation. To ensure reliable performance, elastomer bags may be designed to perform under various pressure conditions to resist deformation and failure. The design may also include reinforcements and / or supports to distribute the pressure more evenly across the bag, reducing the risk of localized stress points that could lead to failure.

[0026] Turning to FIG. 2, if a bag is subjected to excessive differential pressure, it may gradually fail by creep into unoccupied external spaces, particularly the space around and beyond the clamp 204 that seals the neck of the bag to the bag frame. The bag frame is a structural component that supports and holds the bag in place within the ESP system. Clamp 204 may comprise a device used to secure the bag to the bag frame, resisting and / or preventing movement or displacement. Excessive differential pressure can occur due to various factors such as rapid changes in well pressure, high flow rates, or blockages in the system. This deformation is often observed around and beyond the clamp that seals the neck of the bag to the bag frame. This pressure can cause the elastomer material to deform and flow into spaces where it is not intended to be, leading to failure. For example, differential pressures exceeding 5-6 psi can lead to creep in elastomer bags. The bag typically folds over the clamp 204, bulges into the empty space beyond the clamp, and tears. To address this issue, alternative designs may include reinforced clamps with larger surface areas to distribute the pressure more evenly and reduce localized stress points. Additionally, support structures such as rigid rings or mesh can be placed around the bag to preventIS22.0592excessive deformation and maintain its integrity under high-pressure conditions. For instance, stainless steel support rings can provide additional strength and prevent creep. Susceptibility to creep of a bag made of a particular elastomer generally increases with increasing temperature, increasing time of exposure, and the presence of aggressive chemicals in the well fluid. Temperatures above 150°C can accelerate the rate of creep, causing the material to deform more quickly. Prolonged exposure to aggressive chemicals such as hydrogen sulfide (H2S) or carbon dioxide (CO2) can weaken the elastomer, making it more prone to creep.

[0027] Furthermore, advanced elastomer formulations may enhance resistance to creep. These formulations may include additives such as carbon black or silica to improve the material's ability to withstand prolonged stress without deforming. The use of multi-layered elastomer bags with different material properties can also provide better performance under varying pressure conditions. For example, an inner layer of high-strength elastomer can provide structural support, while an outer layer with chemical resistance can protect against aggressive well fluids.

[0028] The differential internal pressure of the bag may be controlled by the opening pressure of the one or more relief valves of the protector that are interposed in series or parallel between the interior of bag and the exterior of the bag.

[0029] In some embodiments, one relief valve has been interposed between the interior and exterior, and the cracking pressure has usually been in the range of 5 to 6 psi. In other embodiments, protector designs may increase both the number of intervening relief valves and their cracking pressure.

[0030] Turning to FIG. 3, the number of intervening relief valves may be increased in the logic of an orthogonal protector. An orthogonal protector may comprise 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 intervening relief valves, in series or parallel, to provide redundancy. The orthogonal protector is designed to enhance the reliability and performance of ESP systems by incorporating multiple relief valves that act in series or parallel to manage pressure differentials. This design ensures that even if one valve fails, others can maintain the necessary pressure balance, preventing damage to the elastomer bags and other components.

[0031] Referring generally to FIG.3, an embodiment of the compensator 356 is illustrated in greater detail. In this embodiment, the compensator 356 is positioned between thrust section 354 and shaft seal module 360. FIG. 3 illustrates a portion of the electric submersible pumping system starting from a head of the motor 324 and working upward to the pump 322. Above theIS22.0592submersible motor 324 is thrust section 354 for carrying thrust loads transferred from the submersible pump 322. The thrust section 354 comprises a lower thrust bearing 362 for carrying downward thrust, an upper thrust bearing 364 for carrying upward thrust, and a runner 366 between them that is joined to a shaft 368. The shaft 368 rotates in a shaft tube 370 and extends from submersible motor 324 to submersible pump 322 to power the submersible pump 322.

[0032] Above the thrust section 354, in this example, is the motor compensator 356 comprising one or more chambers 372 containing one or more corresponding pressure compensators 374. Multiple compensator chambers 372 may be arranged in parallel to provide greater compensation volume and / or in series to provide redundancy. The pressure compensator or compensators 374 may be formed from a variety of structures, such as elastomer bags or bellows, e.g. metal bellows. In the embodiment illustrated, the pressure compensator 374 is in the form of annular metal bellows having an annular inner bellows portion 376 joined with an annular outer bellows portion 378 to form a bellows interior 380. In another embodiment, the pressure compensator 374 may be in the form of multiple metal bellows arranged around the shaft 368 like bullets in a revolver. The structure of pressure compensator / metal bellows 374 provides high reliability and may provide greater displacement per unit length than can be achieved with parallel arrangements of metal bellows. However, embodiments described herein may utilize a single, serial, and / or parallel arrangement of metal bellows pressure compensators 374. If elastomer bags are used as pressure compensators 374, a series arrangement can be helpful in various applications.

[0033] In the embodiment illustrated in FIG. 3, one side of the bellows 374, e g. bellows interior 80, communicates with the motor 324 via a communication passage 382. The other side of bellows 374, e.g. the outside of bellows 374 within chamber 372, communicates to the wellbore 328 via a passage 384 extending to a pressure port 386 located along the exterior of compensator 356. Thus, the compensator 356 and its internal pressure compensator / bellows 374 breathes to the wellbore 328 and not through the shaft seal module 360. In other words, the pressure compensation between the internal fluid of submersible motor 324 and the external well fluid in the annulus surrounding pumping system 320 is achieved directly by the compensator 356 rather than through the shaft seal module 360. In this embodiment, the submersible motor 324 communicates with the interior 380 of the bellows 374 between the inner bellows portion 376 and outer bellows portion 378 via passage 382, and the wellbore 328 communicates with the exterior of the bellows 374 within a chamber 372 via passage 384.IS22.0592

[0034] In the embodiment illustrated, the pressure compensator, e.g. bellows, 374 may be located between an upper body 388 and a lower body 390 of compensator 356. The upper body 388 and the lower body 390 may be connected by an outer housing 392 which forms interior chamber or chambers 372 in cooperation with upper body 388, lower body 390, and shaft tube 370. By way of example, the bellows 374 may be suspended from the upper body 388. In some applications, bubbles can vent from the bellows 374 through a relief valve 394 disposed along a relief flow path 395. By way of example, the relief flow path 395 may be oriented so the bubbles can vent through the shaft seal module 360. Such venting may occur during oil filling and in the event gas is liberated from the oil during operation.

[0035] Well solids that enter the chamber 372 can settle out below the bellows 374. Additionally, a filter 396 may be positioned at or along passage 384 to filter out solids from well fluid which enters passage 384 via port 386. The filter 396 may be constructed in a variety of configurations, such as the illustrated embodiment having a circular cross- section which provides a filtering surface along its circumference. The compensator 356 may further comprise one or more shaft seals 398, such as the shaft seal 398 illustrated as positioned proximate upper body 388.

[0036] In some applications, a relief valve, e.g. relief valve 394, also may be provided in cooperation with the motor compensator 356 to enable excess volume of oil to be discharged from the submersible motor 324 into the shaft seal module 360. The excess volume of oil entering the shaft seal module 360 is eventually discharged into the wellbore through, for example, multiple redundant relief valves. In some applications, this excess volume of oil is discharged through the shaft seal module 360 instead of directly to the wellbore to provide redundancy of relief valves via the plurality of relief valves. Once the submersible motor 24 has reached maximum operating temperature and expelled excess oil, the relief valves would not normally open again and there would be no further communication between the motor compensator 356 and the shaft seal module 360. In an embodiment, the relief valve or valves 94 also may be located in the upper body 388 above the metal bellows 74 to help vent gas liberated from the motor oil used within motor 324.

[0037] Referring again to FIG. 3, the filter 396 may be provided within the motor compensator 356 to exclude solids, such as sand, from the chamber 372 outside the bellows 374. Otherwise, solids could lodge in crevices between portions, e.g. between diaphragms, of bellows portions 376, 378 and restrict the bellows 374 from fully collapsing. Hard solids, such as sand,IS22.0592could also deform the thin metal diaphragms / bellows portions of the bellows 374 if the bellows 374 is constructed as a metal bellows.

[0038] Depending on the application, the filter 396 may be located at the end of the chamber 372, either above or below the pressure compensator / bellows 374. By way of example, the filter 396 may be an annular pleated filter of sand screen material to maximize the filter element area per cubic inch of filter volume. In the illustrated example, this compact filter is attached to the lower body 390 below the pressure compensating bellows 374. The interior space of the filter 396 communicates downwardly through the body 390 below it, which in turn communicates to the wellbore 328 via passage 384 and external pressure port 386. This permits solids to drain from the filter 396 and back to the wellbore 328 instead of being trapped.

[0039] In another embodiment, the filter 396 may comprise a cylinder of sand screen material encircling the outer surface of the bellows 374. This type of filter 396 can be housed between two perforated metal housings, one inside the filter and the other outside the filter in, on, and / or outside the housing of chamber 372. In this embodiment, the filter 396 may include a longitudinal groove or channel for the power cable 344 so that the diameter of the chamber 372 and filter 396 may be maximized without causing undue interference with the cable. In the embodiment illustrated in FIG. 3, the shaft seal module 360 is an independent module located above the motor compensator 56. By way of example, the shaft seal module 360 may comprise a plurality of redundant chambers, as illustrated schematically in FIG. 3. Each of the redundant chambers of the shaft seal module 360 may comprise a variety of components depending on the parameters of a given application. For example, each redundant chamber may comprise a shaft seal 104 positioned about the shaft 68 to prevent interchange of motor oil and well fluid.

[0040] Referring again to FIG. 3, housing 392 may enclose the entire ESP system, providing protection and structural integrity. A housing may comprise an enclosure that surrounds and protects the internal components of the ESP system. Housing 392 may be made of high-strength materials such as stainless steel or titanium to withstand harsh well conditions. Surrounding components of the ESP system, the housing may provide a protective barrier against external forces. Housing 392 may be coupled to, in contact with, or contain, at least in part, the upper body 388, lower body 390, and shaft seal module (SSM) 360 to ensure the stability and integrity of the ESP system.IS22.0592

[0041] Pump 322 may form a part of the ESP system and may be a multistage centrifugal pump that provides the fluid with additional lift or transfer pressure to get the fluid to flow out of the wellbore at a given pace. Each stage may contain a rotating impeller and stationary diffusers that convert the fluid's velocity into pressure. Positioned towards the bottom of the ESP system, the pump 322 may be driven by the motor and is responsible for lifting fluids from the wellbore to the surface. The pump 322 may be coupled to the motor and shaft to ensure efficient fluid movement.

[0042] SSM 360 may prevent well fluids from entering the motor and protect the motor oil from contamination. The SSM 360 may include one or more mechanical seals and / or labyrinth seals that create a barrier against fluid ingress. The SSM 360 may be located between the motor and the pump and ensure that the motor remains uncontaminated by well fluids. The SSM 360 may interact with the motor and housing to maintain the integrity of the ESP system.

[0043] SSM 360 may prevent well fluids from entering the motor and protect the motor oil from contamination. It may include one or more mechanical seals and labyrinth seals that create a barrier against fluid ingress. Positioned between the motor and the pump in some embodiments, the shaft seal module ensures that the motor remains uncontaminated by well fluids. SSM 360 may interact with the motor and housing to maintain the integrity of the ESP system. Additionally, the SSM 360 may work with the relief valves to manage pressure differentials and prevent overpressure conditions. By preventing well fluids from entering the motor, SSM 360 may ensure that the motor oil remains clean and the motor operates efficiently. This helps extend the run life of the ESP system and reduces the risk of motor failure due to contamination.

[0044] Upper body 388 may house the motor compensator 356 and the one or more relief valves 394. A motor compensator may comprise a device that balances the internal pressure of the motor oil with the external well fluid pressure, allowing for thermal expansion and contraction. Upper body 388 may be designed to withstand high pressures and temperatures, providing structural support to the ESP system. The upper body 388, which may be positioned above the motor, may provide a protective enclosure for the motor compensator 356 and relief valves 394. Upper body 388 may be connected to the housing 392 and lower body 390 to ensure the stability of the ESP system.

[0045] Motor compensator 356 may balance the internal pressure of the motor oil with the external well fluid pressure. Motor compensator 356 may allow for the expansion and contractionIS22.0592of motor oil during thermal cycles, ensuring the motor is filled with the correct volume of oil. The motor compensator, which may be positioned within the upper body, may interact with the relief valves 94 and elastomer bags to maintain pressure balance. Motor compensator 56 may ensure the motor operates efficiently by accommodating thermal expansion and contraction.

[0046] One or more relief valves 394 may manage pressure differentials within the ESP protector. Relief valves 394 may open at predetermined pressures to discharge excess motor oil, preventing overpressure conditions that could damage the elastomer bags. The relief valves 394, which may be located within the upper body, may interact with the motor compensator 356 and elastomer bags to maintain pressure balance. Relief valves 394 may ensure the safe operation of the ESP system by preventing over pressurized conditions.

[0047] Shaft 368 may transmit torque from the motor 324 to the pump 322, driving the impellers and enabling fluid movement. Shaft 368 may handle high rotational speeds and loads. Shaft 368, which may be positioned within the shaft tube, may interact with the motor and pump to ensure efficient fluid movement. The shaft tube may comprise a cylindrical component that encases the shaft, providing structural support and protection.

[0048] Lower body 390 may support the inner bellows and other components, providing structural stability to the ESP system. It is designed to withstand high pressures and temperatures. Positioned below the motor, the lower body provides a protective enclosure for the inner bellows and other components. It interacts with the housing and upper body to ensure the stability of the ESP system.

[0049] The inner bellows 376 may comprise one or more flexible components that accommodate the expansion and contraction of motor oil. Inner bellows 376 may be comprised of high-strength elastomers or metals to withstand pressure differentials. Inner bellows 376, which may be located in the upper body 388 or lower body 390, may interact with the motor compensator 356 and relief valves 394 to maintain pressure balance. Inner bellows 376 may ensure the motor operates efficiently by accommodating thermal expansion and contraction.

[0050] Annular metal bellows 374 may provide an impervious barrier to well fluids, preventing fluid ingress into the motor. Annular metal bellows 374 may be rated for high-temperature applications and offer superior resistance to aggressive chemicals. Annular metal bellows 374 may be positioned within the upper or the lower body, the annular metal bellows mayIS22.0592interact with the inner bellows and housing to maintain pressure balance. Annular metal bellows 374 may ensure the motor remains uncontaminated by well fluids.

[0051] Outer bellows 378 may provide additional support and protection to the inner bellows, ensuring the integrity of the ESP system under high-pressure conditions. Outer bellows 378 may be located within the lower body or the upper body, and may interact with the inner bellows and housing to maintain pressure balance. Outer bellows 378 may provide additional strength and protection to the ESP system.

[0052] Shaft tube 370 may enclose the shaft, providing protection and structural support. Shaft tube 370 may be designed to withstand high rotational speeds and loads. Shaft tube 370 may be positioned around the shaft, and may interact with the motor and pump to ensure efficient fluid movement. Shaft tube 370 may provide a protective barrier for the shaft.

[0053] Annular pleated filter 396 may remove debris and contaminants from the motor oil, ensuring the motor operates smoothly and efficiently. Annular Pleated filter 396 may be located within the upper body or lower body, and may interact with the motor compensator and relief valves to maintain pressure balance. Annular Pleated filter 396 may ensure the motor oil remains clean and free of contaminants.

[0054] Hole to wellbore 386 (may also be called port) may allow fluid to enter the ESP system, enabling fluid movement and pressure management. Hole to Wellbore 386 may be positioned at the bottom of the ESP system. The hole to wellbore 386 may have various shapes (circular, rectangular, triangular) and may be tapered in size with regard to width or length.

[0055] Thrust section 354 may carry the pump thrust load, preventing damage to the motor. Thrust section 354 may include one or more thrust bearings that handle high loads and rotational speeds. Thrust section 354 may be located within or adjacent to the lower body.

[0056] The motor 324 may drive the ESP system, providing the necessary power to lift fluids from the wellbore. The motor 324 may be an induction motor or permanent magnet motor (PMM) that operates at high rotational speeds. Positioned at the bottom of the ESP system in some embodiments, the motor interacts with the shaft and pump to ensure efficient fluid movement.

[0057] In some embodiments, the pressure of individual relief valves has been increased to the range of 12 to 15 psi in order to provide greater spring force that may produce a more reliable seal, especially in the presence of solids such as asphaltenes. This increase in pressure is particularly beneficial in environments where the well fluids contain a high concentration of solids,IS22.0592which can interfere with the sealing mechanism of the relief valves. By increasing the spring force, the relief valves can maintain a tighter seal, preventing leaks and ensuring the integrity of the ESP system. The higher pressure relief valves may be used with metal bellows rather than bags due to susceptibility of bags to creep failure.

[0058] Metal bellows, in some cases, have been preferred in high-pressure applications because they offer high resistance to deformation and creep compared to elastomer bags. The metal bellows are typically made from materials such as stainless steel or Inconel, which can withstand the harsh conditions of the well environment, including high temperatures and corrosive fluids.

[0059] The use of metal bellows also allows for the implementation of more complex relief valve configurations, such as multi-stage valves that can provide a more gradual release of pressure. This can help to further enhance the reliability and performance of the ESP system. Additionally, metal bellows can be designed with various geometries and thicknesses to optimize their performance for specific applications, providing greater flexibility in the design of the ESP protector.

[0060] Despite these advantages, the use of metal bellows is not without its challenges. The manufacturing process for metal bellows is more complex and costly compared to elastomer bags, and they require precise engineering to ensure proper fit and function within the ESP system. Furthermore, metal bellows can be more susceptible to fatigue and failure over time, particularly in applications with frequent pressure cycling. To address these challenges, this application presents improvements in materials and designs compared to standard metal bellows to enhance durability and performance in high-pressure applications.

[0061] Turning to FIG. 4, the desire for a bag support has been recognized on certain bags, which were more prone to creep failure than smaller bags due to the larger radial space between the neck of the bag and the ID of the housing. A bag support may comprise a structure that supports the external surface of the bag, preventing deformation and creep. Partial bag support 404 may be implemented for conventional protector designs featuring one intervening relief valve with 5 psi cracking pressure. The bag support 404 may be trapped between a shoulder on the bag frame and a snap ring. Partial bag support design may leave a portion of the bag around the clamp unsupported due to the difficulty of fitting a bag support to the clamp and its buckle. The bag support may be trapped with a retainer ring.IS22.0592

[0062] Conventional ESP motor and protector (e.g., seal section) may be filled with a dielectric, lubricating motor oil. Several embodiments may comprise features in an ESP protector that promote purging of gas from the motor oil in non-vertical applications. This is helpful because free gas can be present in the motor oil from at least the four sources below:

[0063] Unwanted air may be trapped in the motor or protector due to incomplete oil filling;

[0064] The oil used for filling may contain some fraction of dissolved gases;

[0065] Gas from the well bore may gradually permeate through elastomer seals and bags and through mechanical shaft seals into the motor oil where it may be in dissolved or liberated form depending on temperature and pressure variations; and

[0066] Motor oils are subject to a degree of gasification over time at temperature and pressure.

[0067] In vertical applications, gas can rise up through the motor and into the protector where it can be trapped or vented from various chamber types.

[0068] Gas that enters during operation is centrifugally trapped under the runner where it can cause thrust bearing failure in the thrust bearing chamber. In a vertical application the gas can pass around the runner during a shut down. However, if a protector is equipped with the gas purging system (GPS), gas may be vented past the runner during operation

[0069] The labyrinth may be a gas trap in which gas collects at the upper end. If a thrust bearing is directly below it, on shutdown of the ESP the standing tube can suck the gas down into the thrust bearing chamber, causing it to fail on restart. Also, since the gas is compressible when the ESP is shut off and well pressure builds, it robs any chambers above it of compensation volume, which can lead to well fluid invasion.

[0070] The bag may have a relief valve to discharge excess oil on initial heatup. Since the valve may be generally located at the upper end of the bag chamber, it can purge gas in a vertical position.

[0071] Turning to FIG. 5, the bag supports may have the following features.

[0072] A portion of the bag support fully encloses the neck of the bag inboard of the clamp, leaving the afore-mentioned small gap between the support and the clamp. Inboard denotes a position nearer the center of the length of the bag, and outboard denotes farther from the center.

[0073] The internal contour of the bag support follows the external contour of the neck of the bag between the clamp on the neck and the ID of the housing 506, leaving only a small gap toIS22.0592accommodate manufacturing tolerances without permitting excessive stretch of the bag before contacting the bag support.

[0074] The internal contour of the bag approaches the ID of the housing 506 within the afore-mentioned gap.

[0075] A short axial distance outboard of the internal contour, the bag support OD may be reduced to permit freer communication and movement of fluids and solids from the internal contour to regions outboard of the bag support 518.

[0076] Radial, axial, and circumferential passages are provided in bag supports for communication to the chamber above the bag or to ports through the wall of the housing 506 or through the body to the well bore.

[0077] The bag support may be configured in various forms to facilitate assembly and securing of it in the protector.

[0078] In some embodiments, the protector may be assembled starting at the lower end. For a protector assembled starting at the upper end, the terms upper and lower may be reversed. See FIG 5

[0079] The lower bag support 526 comprises a single, complete ring that supports the bag from the clamp to the housing 506, except for the afore-mentioned gaps.

[0080] The lower bag support 526 may be fixed against rotation and vibration relative the lower body 516 or the relief valve mounting ring 514 by means of friction of an O-ring squeezed between the lower bag support 526 and the lower body 516, or the relief valve mounting ring 514, or the housing 506, alternatively by a pin or other fastener in one part and a hole in the other.

[0081] The OD of the lower bag support 526 engages a shoulder in the ID of the housing 506 that prevents the lower bag support 526 from moving upward.

[0082] The upper bag support comprises an inboard portion and a separate outboard portion.

[0083] Each portion (inboard and outboard) comprises a complete ring.

[0084] The inboard upper bag support supports the bag from the clamp to the housing 506, except for the afore-mentioned gaps.

[0085] The outboard upper bag support envelops the bag clamp. A recess in the internal diameter of the outboard upper bag support is provided to accommodate the clamp buckle to prevent transmission of deleterious forces on the buckle.IS22.0592

[0086] The outboard upper bag support is fixed against rotation and vibration relative the housing 506 by friction of an O-ring squeezed between those two components.

[0087] Assembly of the major components is as follows, not mentioning smaller components unrelated to the bag supports:

[0088] The bag is installed on the upper 522 and lower bag frame 528, but the clamps are not installed at this time.

[0089] The lower bag support 526 is loosely assembled over the neck of the bag. The clamp is then installed outboard of the lower bag support 526.

[0090] The inboard upper bag support 520 is loosely assembled over the neck of the bag. The clamp is then installed outboard of the inboard upper bag support 520.

[0091] The O-ring is installed in the groove in the OD of the lower bag support 526.

[0092] The lower bag frame 528 is then installed in the lower body 516 (the body immediately below the subject bag), so that the lower bag support 526 is prevented from moving farther downward than design by contact with the lower body 516 or with another component if present, such as a relief valve mounting ring 514. Any fasteners for the lower bag frame 528 as mentioned above are installed at this time.

[0093] The housing 506 is then installed and threaded to the lower body 516.

[0094] The O-ring is installed in the groove in the OD of the outboard upper bag support.

[0095] The inboard upper bag support 520 is rotated for alignment of the screw holes and the recess for the bag clamp buckle in the outboard upper bag support. The outboard upper bag support is then installed and fastened with screws. Note that the shoulder in the ID of the housing 506 prevents the outboard upper bag support from moving farther downward.

[0096] The upper body 504 is then threaded to the housing 506, blocking the outboard upper bag support from moving upward.

[0097] Other embodiments include multiple variations that may be used in combination with any other embodiment.

[0098] Any of the components in the form of a ring may be divided into segments of a circle that join together to form a complete circle, enabling radial assembly of the component over the bag or bag frame.

[0099] Segments of circles may be joined by fasteners, e.g. tangential screws, pins, clips.IS22.0592

[0100] Segments of circles may be retained together by a close fit in the housing 506, by a retainer ring, an outer sleeve, wire, or other part.

[0101] The outboard upper bag support or part of similar function may comprise multiple pieces that do not form a full circle, e.g. gaps remain between them after assembly.

[0102] The outboard upper bag support 518 may be joined to the inboard upper bag support 520 by other means, including pins, threading, clips, wire, expanding fasteners, interference fit, crimping, swaging, etc.

[0103] Any of the bag support components, whether whole circle or segments, may be retained from moving upward, downward, or rotationally by trapping an inward projection between neighboring parts. A neighboring part may be a component or element that is adjacent to or in close proximity to another specified component within the ESP system. Trapping may comprise securing or holding in place by surrounding components or structures, resisting movement or displacement.

[0104] The lower bag support 526 may comprise a portion smaller in ID than the lower bag frame 528 OD. The portion smaller in internal diameter may be trapped between the lower bag frame and the lower body or the lower bag frame and the relief valve mounting ring.

[0105] The upper bag support may comprise a portion smaller in ID than the upper bag frame 522 OD. The portion smaller in diameter may be trapped between the upper bag frame and the upper body or the upper bag frame and a retainer ring.

[0106] The several innovative aspects of the current application address the issues with prior art discussed above to effectively vent gas at low angle installations. For example, in subsea skids ESPs are typically installed at approximately 5 degrees from horizontal, though the same innovations may be utilized at even lower angles. Benefits include more perfect venting and avoidance of the expense of timing threads. These benefits are accomplished by the following aspects, which may be employed solo or in concert.

[0107] The volume between the inner bellows and the shaft tube 524 is vented by a circle of holes that ensures one hole with be on the upper side to vent gas.

[0108] The angular orientation of the vent hole through the upper body likewise may determine the size of the gas trap, unless the threads are timed or multiple holes are provided. A timed thread may refer to a threaded connection where the orientation of the thread is controlledIS22.0592so that, when the connection is fully torqued, certain features — like ports, slots, keyways, or alignment holes — are in the correct position relative to other components.

[0109] The relief valve orientation likewise may determine the size of the gas trap unless the threads are timed.

[0110] The current application comprises features and methods for fully supporting the external surface of an ESP protector bag to prevent it from creeping, over-expanding, and rupturing due to higher differential pressure induced by a greater number of intervening relief valves of higher cracking pressure.

[0111] The bag support supports the entire external surface of bag that is not otherwise covered by the housing 506, bag frame, shaft tube 524, and clamps. The exceptions are:

[0112] Small gaps, e.g. 1 / 32”, are provided between the support and the housing 506 and between the support and the bag clamp. Also, small holes, e g. 1 / 8” diameter, are provided in the bag frame.

[0113] The gaps and holes are sized sufficiently large to permit free flow of fluids and solids into and out of the space around the bag as it contracts 510 and expands 508.

[0114] The gaps and holes are sized sufficiently small to prevent extrusion or creep of the elastomer bag at the maximum pressure differential for the required life of the ESP at its service temperature and chemical exposure. Pressure capacity may be increased as required by reducing the size but increasing the number of such gaps and holes, the limiting case being a bag support constructed of fine metal mesh.

[0115] The gaps are also sized to accommodate accumulation of manufacturing tolerances to prevent excessive gaps or unwanted interference between parts.

[0116] Turning to FIG. 6, a cross-sectional view of a portion of the electric submersible pumping system 22 is provided to illustrate an example of the thrust bearing section 28 combined with a gas purging system 56. The gas purging system 56 comprises features which operate to remove gas from the thrust bearing section 28 which could otherwise cause wear or even failure of the thrust bearing section 28. However, the gas purging system 56 may be used to remove gas from other portions of electric submersible pumping system 22 or from other well string components.

[0117] In the illustrated example, the thrust bearing section 28 comprises a thrust runner 58 which works in cooperation with at least one thrust bearing, such as a down thrust bearing 60IS22.0592and an up thrust bearing 62. By way of example, the thrust runner 58 may be mounted to a shaft 64 rotationally mounted within a shaft tube 66. The shaft 64 may be part of a multi-segment shaft by which submersible motor 26 powers submersible pump 24.

[0118] During operation of submersible pump 24, the thrust of the submersible pump 24 is transferred through shaft 64 and countered via thrust bearing section 28. The thrust runner 58 rotates with shaft 64 and is forced axially against thrust bearing 60 to counter down thrust or against thrust bearing 62 to counter up thrust. A motor oil 68 may move between submersible motor 26 and thrust bearing section 28 via, for example, a flow passage 70 extending through a bulkhead 72. The bulkhead 72 as well as thrust bearing section 28 may be disposed within sections of an outer housing 74. A small gap 76 may be disposed between thrust runner 58 and the surrounding outer housing 74 to enable rotation of thrust runner 58 within outer housing 74.

[0119] During rotation of thrust runner 58, centrifugal separation of a gas 78 from motor oil 68 may occur which causes the gas 78 to accumulate at a radially inward region 80. As illustrated, the radially inward region 80 may occur along shaft 64 proximate thrust runner 58 and corresponding thrust bearing 60. As explained in greater detail below, the gas 78 may be vented via gas purging system 56 so as to ensure a suitable fdm of the motor oil 68 remains between thrust runner 58 and the corresponding thrust bearing(s) 60 / 62.

[0120] It should be noted the gas 78 may be contained within a gassy oil portion of the motor oil 68. For example, the centrifugal action of thrust runner 58 may cause formation of a lighter weight, mixed ratio oil containing gas 78. The lighter weight oil containing gas 78 moves to radially inward region 80 while the heavier motor oil 68 (containing no gas or reduced gas) moves radially outward relative to region 80. The gas purging system 56 is able to remove gas 78 by removing the lighter weight mixed ratio oil from radially inward region 80. The centrifugal action results when thrust runner 58 rotates relative to stationary thrust bearings 60 / 62 which may be rotationally fixed with respect to outer housing 74 via a variety of mounting structures 82.

[0121] According to the embodiment illustrated in FIG. 6, gas purging system 56 utilizes shaft 64 in combination with a gas pumping feature 84 to move gas 78 away from the radially inward region 80 proximate thrust runner 58. By way of example, the gas pumping feature 84 may comprise a groove 86 disposed along an exterior (or interior) of shaft 64. The groove 86 operates during rotation of shaft 64 to move gas 78 from region 80 to, for example, a sump chamber 88.IS22.0592

[0122] By way of further example, the groove 86 may be a helical groove milled or otherwise formed along an exterior of shaft 64 so as to create the desired gas pumping action during rotation of shaft 64. Effectively, the helical groove 86 works as a screw pump which moves the gas 78 (e.g. gas 78 contained in gassy oil) along the shaft 64 to sump chamber 88. In some embodiments, the groove 86 may extend at least partially through thrust runner 58 and along an exterior surface of shaft 64 or along the interior of shaft 64. Various gaps may be formed along rings, radial bearings, and other features disposed along shaft 64 to ensure the flow of gas 78 from the desired region, e g. radially inward region 80, to sump chamber 88.

[0123] The sump chamber 88 of gas purging system 56 may be positioned to receive the gas 78 from pumping feature 84 via a diffuser 90, e.g. a radial opening or openings 92, formed through shaft tube 66. The sump chamber 88 may be formed between shaft tube 66 and a surrounding section of outer housing 74. In some embodiments, the diffuser 90 is constructed with radial openings 92 arranged at an angle which positively directs the gas 78 away from the shaft 64. The diffuser 90 also may have vanes or other features attached to the shaft tube 66 which curve from a generally circumferential orientation to a generally radial orientation. Additionally, the diffuser 90 may have helical passages arranged with respect to shaft 64 to change the direction of flow from generally axial to generally radial. In some embodiments, the groove 86 also may be reversed in orientation or combined with other features downstream of diffuser 90 to limit the amount of gas, e g. bubbles, flowing past the diffuser 90.

[0124] In the embodiment illustrated, the gas purging system 56 also comprises a body section 94 disposed between the sump chamber 88 and the thrust runner 58. The body section 94 may comprise a plurality of passages 96 in the form of recirculation passages oriented at a desired angle relative to shaft 64. For example, the recirculation passages 96 may be oriented through body section 94 such that ends of the passages 96 proximate sump chamber 88 are at a radially inward position while ends of the passages 96 proximate thrust bearing section 28 are at a radially outward position as illustrated.

[0125] When the electric submersible pumping system 22 is oriented horizontally, heavier motor oil 68 settles downwardly and lighter gas 78 moves upwardly in the sump chamber 88 as illustrated in FIG. 6. During rotation of shaft 64 and movement of gassy oil along groove 86, the head established by motor oil 68 in sump chamber 88 facilitates an additional pumping action as the heavier motor oil 68 moves from sump chamber 88 back to thrust bearing section 28 along theIS22.0592lower recirculation passages 96. This movement effectively forces movement of gas 78 or lighter weight gassy oil from a radially outward / upper region 98 located proximate upper thrust bearing 62. The gas 78 (e.g. gas 78 contained within a gassy oil) is moved from region 98, along the upper recirculation passages 96, and into sump chamber 88 as indicated by circulation arrows 100. This pumping action along recirculation passages 96 further facilitates removal of gas 78 from thrust bearing section 28.

[0126] Depending on the parameters of a given application, the gas purging system 56 and thrust bearing section 28 may be located adjacent to or within various components of electric submersible pumping system 22 and may comprise various other and / or additional features such as access ports 102 and radial bearing assemblies 104. The ESP may comprise a thrust bearing chamber and a gas separation chamber above it that cooperate to pump gas via a spiral groove in the shaft from below the thrust runner up to the gas separation chamber and return relatively gas-free motor oil to the thrust bearing chamber.

[0127] Turning to FIG. 7, examples of additional features and components which may be included in gas purging system 56 are illustrated.

[0128] In the embodiment of FIG. 7, gas purging system 56 comprises at least one baffle 106 oriented generally radially between shaft tube 66 and the surrounding section of housing 74.

[0129] By way of example, the at least one baffle 106 may comprise a plurality of baffles 106 having passages 108 therethrough to enable movement of fluid along sump chamber 88 while limiting fluid agitation. By baffling the fluid in sump chamber 88, gas 78 is better able to separate from motor oil 68 for collection along an upper region of the sump chamber 88 as illustrated. It should be noted the embodiment of FIG. 7 illustrates diffuser 90 as positioned at a distal end of sump chamber 88 relative to thrust bearing section 28.

[0130] The gas purging system 56 also may comprise other features such as a plurality of gas discharge passages 110 routed from the sump chamber 88 to a collection space 112 and then to a relief valve 114. The gas discharge passages 110 and relief valve 114 cooperate to discharge gas from sump chamber 88 to, for example, annulus 50 surrounding the electric submersible pumping system 22. The relief valve 114 may be selected so as to crack or shift to an open flow position when the pressure of gas 78 acting on relief valve 114 reaches a predetermined cracking pressure. In some embodiments, a plurality of relief valves 114 may be positioned to ensure atIS22.0592least one of the relief valves 114 is positioned toward a top side regardless of the orientation of the electric submersible pumping system 22.

[0131] According to an embodiment, the gas discharge passages 110 may be routed through a second body section 116 located on an opposite side of sump chamber 88 relative to body section 94. The body section 94 and second body section 116 may be connected by a section of the outer housing 74. Additionally, the size of gas discharge passages 110 may be selected to limit the flow of motor oil 68 therethrough while readily flowing gas 78 to facilitate removal of gas 78 from sump chamber 88.

[0132] The gas retained in the separation chamber is vented through the upper body (the body above the chamber) through a circular pattern of vent holes. The holes are very small in diameter so that gas will preferentially flow to the relief valve regardless of the relief valve’s rotational orientation.

[0133] Turning to FIG. 8, another example of an ESP 44 oriented at a predetermined angle of rotation for use is illustrated. ESP 44 is positioned in a capsule 116 having an inflow conduit 12 for receiving a production fluid 10 to be energized by the ESP and discharged through a discharge conduit 14 of the ESP 44. In one example, receiving structure 112 may be located on a surface 28 such as a seabed, the inflow conduit 12 connected for example to a subsea wellbore whereby ESP 44 is utilized as a booster pump for producing fluid 10 to the surface of the water. According to another aspect, the present disclosure involves gravity separation of fluids in an ESP 44 installed at a low angle 58 (i.e., an angle of less than about 30 degrees from horizontal or more than about 60 degrees from vertical 60). In this aspect, the least permissible angle of operation with respect to the earth is minimized by combination with other aspects of the disclosure to an angle of greater than about 60 degrees from vertical and greater than about 0 degrees from horizontal.

[0134] This type of chamber may not normally be under consideration for non-vertical application. However, a low angle system for extending the function of a labyrinth to greater deviation from vertical may be utilized. This is achieved by rotational orientation of the standing and hanging tubes in relation to the earth. Several methods of doing this are disclosed, the more practical for subsea skid protectors being timing of the threads on the bodies to advantageously orient tubes, a cumbersome and costly method.IS22.0592

[0135] Turning to FIG. 9, as the angle from vertical increases, the bag can form a larger gas trap. This is due to the following issues, the most restrictive of which governs the size of the gas trapped in the bag.

[0136] In order for the bag to collapse properly, the end is molded smaller in diameter than the main body, creating a gas trap in a near horizontal application. With larger diameter bags, in order to remove it from the mold one end is usually much larger than the other. To facilitate assembly, the smaller end is generally oriented upward, creating a bottle neck that amplifies the gas trap.

[0137] The vent from the bag to the passageway through the upper body (the body above the bag) is generally a one or two holes that are randomly angularly located unless the ESP is installed in a seabed skid and the threads are timed to orient the hole on the upper side.

[0138] The relief valve 512 for the bag is also installed in the body that is randomly angularly oriented except with thread timing in a skid. Multiple relief valves may not be used in the same way as multiple vent holes because one may unpredictably open first. Furthermore, multiple relief valves may increase potential for leakage.

[0139] For metal bellows, there may be similarities to bags with the aspects governing the potential for trapping gas in a low angle installation.

[0140] Turning to FIG.10, with the annular bellows opening facing downward, the bubble deflector may not function optimally. Annular metal bellows may be installed with the annular opening facing downward to form an absolute gas trap. A bubble deflector at the opening can prevent some bubbles from entering in vertical installations, but any that do enter become trapped in the bellows. This has been greatly improved in recent designs with the annular opening facing upward.

[0141] In non-vertical applications of with deviation from vertical ranging up to 85° from vertical, e.g. the 5° from horizontal that is common in subsea skids, the tendency to trap gas becomes more pronounced.

[0142] Regarding the thrust bearing chamber, even during a shutdown, some gas may not be purged, making the GPS more useful to reliability and long life since it positively pumps gas past the runner during operation.IS22.0592

[0143] A GPS for an ESP system is designed to work at any angle of installation without control of the angle of rotation. It may be used in steam-assisted gravity drainage (SAGD) nearhorizontal wells.

[0144] Turning to FIG. 11, with the annular bellows opening facing upwards, the upper flange of the bellows features a circle of multiple holes at a radius near the minor diameter of the outer bellows ensuring that one hole will be on the upper side to effectively vent gas without rotationally orienting it.

[0145] Turning now to FIG. 12, the following features may avoid or minimize gas traps without timing threads.

[0146] In some embodiments, the normal orientation of the bag may be reversed so that the larger end is upward, enabling venting almost all of the gas from the bag.

[0147] In some embodiments, the ESP may provide multiple vent holes 1208 (e g., a circle of multiple vents, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, here and elsewhere) through the upper bag frame 522 adjacent or near to the inner diameter of the end of the bag to ensure that at least one hole will be on the upper side, thus enabling gas to be vented in any rotational orientation of the upper bag frame 522. This eliminates the need to orient the bag frame assembly in the lower body 516 (the body below the bag), an orientation that with some designs may be unintentionally changed during other assembly operations or during ESP operation.

[0148] In some embodiments, the ESP may provide a circle of multiple vent holes 1208 through the upper body 504 at a radius that at the angle of installation would not be materially lower than the inner diameter of the upper end of the bag 1210 or than the uppermost vent hole in the upper bag frame 522. In some embodiments, the ESP may provide another circle of holes to vent gas from internal feature of the body, such as the regions around the shaft seal 530 and the radial bearing. These measures obviate the need for timing threads to vent the upper body 504.

[0149] Mount the relief valve 512 in a separate mounting ring that is assembled to the upper body 504 after the upper body 504 has already been screwed into the housing 506 (See FIG.5). The rotational orientation of the mounting ring to the upper body 504 may be variable to enable the relief valve to be oriented on what will be the upper side of the ESP when it is later installed in a skid or other orientable installation. In the preferred embodiment, the mounting ring is sealingly fixed to the upper body 504 with O-rings and a circular pattern of screws that can be indexed to position the relief valve on the upper side. Another means is a pin in one part thatIS22.0592engages one of a circle of holes in the other part. Another means is a tight diametral fit. The entrance to the relief valve may be located at a radius that at the angle of installation will not be materially lower than the inner diameter of the upper end of the bag or of the uppermost vent hole in the upper body 504. This avoids the need to time threads to avoid creating a gas trap.

[0150] Alternatively, the relief valve may be assembled directly into one of several ports in the upper body 504. The port that may be uppermost when installed in the skid or other orientable installation is selected after screwing the upper body 504 into the housing 506. The unused holes may be plugged. The ports may be in a circular, rectangular, square, triangular, linear, arced, and / or hyperbolic pattern and communicate with the vent holes in the upper body 504.

[0151] Regarding metal bellows 1214, in a low angle application such as a 5° subsea skid, timing of the threads may be used to orient the relief valve on the upper side to positively vent the bellows and prevent creation of a substantial gas trap in the bellows. The current application removes the need to time the threads.

[0152] As with the bag chamber, the relief valve may be mounted in a mounting ring.

[0153] Alternatively, as with the bag chamber, the relief valve may be assembled into the port in the upper body 504 that will be uppermost, and the other ports are plugged.

[0154] 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.

[0155] 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 aIS22.0592desired 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.

[0156] 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.

Claims

IS22.0592CLAIMSWhat is claimed is:

1. An electric submersible pump (ESP) comprising:a housing enclosing the ESP;a bag frame comprising an upper bag frame and a lower bag frame;a bag supported by the bag frame;a shaft tube extending through the housing and the bag frame;a clamp configured to secure the bag to the bag frame; anda bag support comprising a lower bag support and an upper bag support, the bag support supporting an external surface of the bag that is uncovered by the housing, the bag frame, the shaft tube, and the clamp,wherein the lower bag support comprises a complete ring that is configured to support the bag from the clamp to the housing.

2. The ESP of claim 1, wherein the upper bag support comprises an inboard portion and an outboard portion, each portion comprising a complete ring.

3. The ESP of claim 2, wherein the inboard portion of the upper bag support supports the bag from the clamp to the housing.

4. The ESP of claim 3, wherein the outboard portion of the upper bag support envelops the bag clamp and comprises a recess configured to accommodate the clamp buckle.

5. The ESP of claim 1, wherein the bag support includes at least one radial, one axial, or one circumferential passage for fluid communication, through the housing, to the chamber above the bag or to one or more ports.

6. The ESP of claim 1, wherein the bag support is fixed against rotation and vibration relative to the housing by friction of an O-ring positioned between the bag support and the housing.IS22.05927. The ESP of claim 1, wherein the bag support is constructed of fine metal mesh to prevent extrusion or creep of the elastomer bag based on pressure differential.

8. The ESP of claim 1, wherein the bag support comprises one or more holes configured to permit free flow of fluids or solids into and out of the space around the bag as the bag contracts and expands.

9. The ESP of claim 1, wherein the bag support is divided into segments of a circle that join together to form a complete circle, enabling radial assembly over the bag or bag frame.

10. The ESP of claim 1, wherein the bag support is retained from moving upward, downward, or rotationally by trapping an inward projection between one or more neighboring parts.

11. A bag support for an electric submersible pump (ESP) comprising:a lower bag support comprising a single, complete ring that supports the bag from the clamp to the housing;an upper bag support comprising an inboard portion and an outboard portion, each portion comprising a complete ring;wherein the inboard portion of the upper bag support is configured to support the bag from the clamp to the housing;wherein the outboard portion of the upper bag support envelops the bag clamp and includes a recess to accommodate a clamp buckle;at least one radial passage, axial passage, or circumferential passage for fluid communication, via the housing, to the chamber above the bag or to ports;one or more holes configured to permit free flow of fluids or solids into and out of the space around the bag as the bag contracts and expands.

12. The bag support of claim 11, wherein the bag support comprises a fine metal mesh to prevent extrusion or creep of the elastomer bag due to pressure differential.IS22.059213. The bag support of claim 11, wherein the bag support is retained from moving upward, downward, or rotationally by trapping an inward projection between one or more neighboring parts.

14. The bag support of claim 11, wherein the lower bag support is fixed against rotation and vibration relative to a lower body by means of friction of an O-ring squeezed between the lower bag support and the lower body.

15. The bag support of claim 14, wherein the lower body is configured to support one or more inner bellows or one or more annular metal bellows.

16. The bag support of claim 11, wherein the bag support comprises one or more gaps between the support and the housing to permit free flow of fluids or solids.

17. The bag support of claim 11, wherein the bag support is divided into one or more segments of a circles that join together to form a complete circle, enabling radial assembly over the bag or bag frame.

18. The bag support of claim 11, wherein the outboard upper bag support is joined to the inboard upper bag support with one or more pins, threading, clips, wire, expanding fasteners, interference fit, crimping, or swaging.

19. The bag support of claim 11, wherein the lower bag support comprises a portion smaller in internal diameter than the lower bag frame outer diameter, wherein the portion smaller in internal diameter is trapped between the lower bag frame and the lower body or the lower bag frame and the relief valve mounting ring.

20. The bag support of claim 11, wherein the upper bag support comprises a portion smaller in internal diameter than the upper bag frame outer diameter, wherein the portion smaller in diameter is trapped between the upper bag frame and the upper body or the upper bag frame and a retainer ring.

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