Seals for Electric Submersible Pump
A submersible pump can include a male part that includes an outer diameter; a female part that includes an inner diameter; an elastomeric seal element disposed between the male part and the female part; and a non-elastomeric seal element disposed between the male part and the female part. Various other apparatuses, systems, methods, etc., are also disclosed.
Latest Schlumberger Technology Corporation Patents:
This application claims the benefit of U.S. Provisional Patent Application having Ser. No. 61/757,335, filed 28 Jan. 2013, which is incorporated by reference herein.
BACKGROUNDVarious types of equipment may be employed in a downhole environment. As an example, artificial lift equipment such as an electric submersible pump (ESP) may be deployed in a downhole environment (e.g., to move fluid). For example, where a substance does not readily flow responsive to existing natural forces, an ESP may be implemented to artificially lift the substance. In such an example, the ESP may include one or more seals that aim to seal an internal space of the ESP from fluid of an external environment. In various examples, technologies, techniques, etc., described herein pertain to equipment seals, for example, to seal one or more interfaces between equipment components.
SUMMARYA submersible pump can include a male part that includes an outer diameter; a female part that includes an inner diameter; an elastomeric seal element disposed between the male part and the female part; and a non-elastomeric seal element disposed between the male part and the female part. Various other apparatuses, systems, methods, etc., are also disclosed.
This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
Features and advantages of the described implementations can be more readily understood by reference to the following description taken in conjunction with the accompanying drawings.
The following description includes the best mode presently contemplated for practicing the described implementations. This description is not to be taken in a limiting sense, but rather is made merely for the purpose of describing the general principles of the implementations. The scope of the described implementations should be ascertained with reference to the issued claims.
Various types of equipment may be employed in a downhole environment that may benefit from one or more seals that aim to seal an internal space from an external environment. As an example, consider artificial lift equipment such as an electric submersible pump (ESP). As an example, an ESP may be deployed for any of a variety of pumping purposes. For example, where a substance does not readily flow responsive to existing natural forces, an ESP may be implemented to artificially lift the substance. In such an example, pressures may exist in a downhole environment and such pressures may change due to operation of the ESP. As an example, an equipment seal that aims to seal an internal environment (e.g., internal to equipment) from an external environment may do so by having an ability to withstand pressures, pressure differentials, etc., including those that may result in part from operation of downhole equipment, etc.
The ESP system 100 of
Referring again to
In the example of
As shown in
In the example of
For FSD controllers, the UniConn™ motor controller can monitor ESP system three-phase currents, three-phase surface voltage, supply voltage and frequency, ESP spinning frequency and leg ground, power factor and motor load.
For VSD units, the UniConn™ motor controller can monitor VSD output current, ESP running current, VSD output voltage, supply voltage, VSD input and VSD output power, VSD output frequency, drive loading, motor load, three-phase ESP running current, three-phase VSD input or output voltage, ESP spinning frequency, and leg-ground.
The UniConn™ motor controller can include control functionality for VSD units such as target speed, minimum and maximum speed and base speed (voltage divided by frequency); three jump frequencies and bandwidths; volts per hertz pattern and start-up boost; ability to start an ESP while the motor is spinning; acceleration and deceleration rates, including start to minimum speed and minimum to target speed to maintain constant pressure/load (e.g., from 0.01 Hz/10,000 s to 1 Hz/s); stop mode with PWM carrier frequency; base speed voltage selection; rocking start frequency, cycle and pattern control; stall protection with automatic speed reduction; changing motor rotation direction without stopping; speed force; speed follower mode; frequency control to maintain constant speed, pressure or load; current unbalance; voltage unbalance; overvoltage and undervoltage; ESP backspin; and leg-ground.
In the example of
In the example of
As an example, the VSD unit 170 may include commercially available control circuitry such as the SpeedStar™ MVD control circuitry marketed by Schlumberger Limited (Houston, Tex.). The SpeedStar™ MVD control circuitry can include a plug-and-play sine wave output filter, a multilevel PWM inverter output, a 0.95 power factor, programmable load reduction (e.g., soft-stall function), speed control circuitry to maintain constant load or pressure, rocking start (e.g., for stuck pumps resulting from scale, sand, etc.), a utility power receptacle, an acquisition system for the Phoenix™ monitoring system (e.g., including sensors), a site communication box to support surveillance and control service, a speed control potentiometer. The SpeedStar™ MVD control circuitry can optionally interface with the UniConn™ motor controller, which may provide some of the foregoing functionality.
In the example of
While the example of
In the example of
As to the ESP 200, during operation, pressures in the ESP may exceed those outside of the ESP 200 such that material (e.g., fluids such as liquid and gas) may leak from inside to outside. As an example, during operation or otherwise, pressures outside the ESP 200 may exceed those inside the ESP 200 such that material (e.g., fluids such as liquid and gas) may leak from outside to inside. For example, the interfaces 220 and 240 of the ESP 200 may be subject to leakage. As an example, housings and internal joints in ESP components may be sealed with elastomer seals such as, for example, rubber O-rings. Elastomer seals tend to be subject to several modes of damage or compromise in various applications. Some examples of elastomer behavior can include: creep, stress relaxation and thermal set; thermal expansion; chemical swell; chemical breakdown; thermal breakdown; glass transition at low temperature; and gas permeation.
As an example, a welded joint may be used to seal two components, for example, rather than use of an elastomer seal. A welded joint may be subject to one or more factors such as, for example: heat distortion of thin housings; leaky welds; over-heating of internal components; difficulty of dismantling and salvaging parts; capital investment in automated welding equipment; and welding engineering, process control and QA/QC specifications.
Various types of equipment for use in a downhole environment can include a housing and one or more other components that are joined to the housing. As an example, a housing may function to protect components, add integrity, etc. As an example, a thick-walled housing may provide greater protection and integrity than a thin-walled housing, however, the thick-walled housing may add more mass and a greater working diameter than a thin-walled housing.
As an example, compared to a thick-walled housing, a thin-walled housing may present some challenges as to sealing. For example, a thick-walled housing may provide for deeper grooves for O-rings, better stress integrity for welds, etc. In other words, a thick-walled housing may provide more material to work with for implementation of sealing features when compared to a thin-walled housing.
In various examples described herein, sealing features are presented that may, for example, be implemented individually or in combinations to help seal a housing. For example, a sealing feature may act to compensate for a lack of wall thickness of a housing, a component or components to provide an adequate seal at a joint or joints.
As an example, an assembly may include two components (e.g., two parts) and a ring where the ring may be positioned to form, at least in part, a seal between the two components. As an example, a ring may be a gland ring, for example, that may form, at least in part, a gland. In such an example, a seal element or seal elements may be disposed in the gland to form a seal, which may be referred to, for example, as a gland seal.
As an example, a gland may be formed by one or more components (e.g., parts) and may be defined as having a volume. As an example, a gland may be a chamber that can receive one or more seal elements. Such a chamber may include one or more openings that may, for example, extend to another chamber, an external environment, etc. As an example, a seal element may be seated in a gland (e.g., a chamber) formed by one or more components (e.g., defined by component surfaces) and may contact surfaces to form a seal, which may be referred to as a gland seal. Such a gland seal may act to seal a joint between two components with respect to two environments. For example, consider a gland seal that seals an internal environment in an assembly from an external environment in which the assembly is located or vice versa. In such an example, fluid may exist (e.g., gas, liquid, multiphase, etc.) in both environments where fluid movement from one environment to another may be detrimental to operation of the assembly. As an example, fluid may be moved responsive to pressure, which may change due to a change in environment, an operational condition, etc.
As an example, fluid in an environment may be chemically active, for example, capable of causing corrosion or other chemical reaction detrimental to material (e.g., metal, alloy, polymers, ceramics, etc.). As an example, well fluid may be chemically active, for example, in a manner that may depend on one or more environmental conditions (e.g., temperature, pressure, etc.). As an example, an assembly may include a seal that acts to prevent intrusion of fluid, which may be a chemically active fluid (e.g., a fluid that includes one or more chemically active constituents).
As an example, a gland may be formed in part by a gland ring. For example, a gland ring may include a surface that defines, at least in part, a gland (e.g., a chamber).
As an example, a ring may be provided to add integrity at a joint formed by two components. As an example, a ring may be provided to bear a load between two components that are joined. For example, a ring may include threads along an outer diameter and a housing may include threads along an inner diameter that allow for threaded receipt of the ring in the housing. In such an example, another component that may include threads may be joined to the housing, for example, via the threads of the housing where the component may joined and axially positioned to abut the ring and, for example, apply a load to the ring. In such an example, the ring may axially locate the component with respect to the housing and form a seal that may help to seal the threaded joint between the component and the housing. In such an example, the ring, the component and/or the housing may include one or more seal features that may help to seal the threaded joint between the component and the housing. For example, the ring may include a notch, an annular groove, etc. that may be configured to receive a seal element (e.g., material from a weld pool, an O-ring, a piston ring, etc.).
As an example, a ring may include or form a shoulder where the shoulder may be a seal feature, for example, to cooperate with a seal element. For example, a shoulder may provide a surface against which a seal element may be seated and optionally loaded (e.g., with an axial load, etc.).
As an example, a ring may be received with respect to a component (e.g., a housing, etc.) via an interference fit (e.g., press-fit or compression fit). In such an example, a ring may be made of metal, alloy, etc. and provide a surface that can be loaded to a rated load without axially movement of the ring. For example, a housing may include a notch along an inner diameter that can axially locate a ring positioned in the housing, for example, via an interference fit. In such an example, the ring may include an inner diameter that is smaller than the inner diameter of the housing, for example, to supply an axial annular face against which another component may be located (e.g., a component joined to the housing, a seal element, etc.).
As an example, a ring may be provided as part of an assembly to allow for achieving a desired amount of torque between components of the assembly. In such an example, the ring may also act to axially locate one component with respect to another component (e.g., act as an axial stop). In such an example, the ring may include one or more features that can help to form a seal at a joint between two components.
As an example, a ring may be provided as part of an assembly that includes two components that are joined to form a joint where the ring may enhance sealing of the joint. As an example, a joint may be configured for receipt of material from a weld pool, for example, where solidification of the material helps to seal the joint.
As an example, a ring may include an inner diameter that exceeds an outer diameter of a component. For example, a ring may be an outer ring that is configured to sit at an outer edge of a joint formed by two components that are joined together. For example, a ring may include an inner diameter that exceeds an outer diameter of a housing and may act to increase structural integrity of the housing at an end of the housing that forms a joint with another component. In such an example, the ring, the housing and/or the component may include one or more features that may provide for seating of a seal element or seal elements that may help to seal the joint.
As an example, a housing or other component may include an increased wall thickness at or proximate to an end. In such an example, the increased wall thickness may provide material for forming or carrying one or more features that may help to form a seal about a joint. For example, a housing may include a thicker annulus at or proximate to an end of the housing to impart one or more features that may assist with preloading (e.g., a preload shoulder for a seal element, etc.), gland formation, etc. As an example, a feature may be a shoulder, a groove, threads, a bayonet, etc.
As an example, a joint may be formed between two or more components of a pump section of a system. As an example, a joint may be formed between two or more components of a protector section of a system. As an example, a joint may be formed between two or more components of a motor section of a system. As an example, a joint may be formed between two or more components of an ESP where, for example, the ESP includes a pump section, a protector section and a motor section. As an example, an ESP may include a motor section coupled to a protector section coupled to a pump section where, for example, the motor section includes an electric motor configured to drive a shaft that extends through the protector section to the pump section to operatively drive a pump of the pump section.
As an example, a protector section may include one or more bellows, for example, one or more metal bellows. In such an example, a joint may exist between a bellows and another component of the protector section. As an example, a ring may be included in the protector section, for example, to support the joint (e.g., structurally, sealably, etc.).
As an example, to enhance sealing of an interface (e.g., a joint, etc.) between two components or parts, a gland may be implemented that enables use of metal and/or polymer seal rings in thin-wall ESP parts. As an example, a seal element may be relatively rigid, for example, to inhibit stretching (e.g., as for O-rings), for example, for assembly into an external groove in a male part (see, e.g.,
As an example, an assembly may include a ring, for example, to facilitate use of one or more metal and/or polymer seal elements to seal a joint or joints between components of the assembly. In such an example, a ring may form a shoulder, for example, that may complete a gland and contain a seal element (e.g., to form a gland seal). As an example, a ring may supply additional thickness to a wall of a component, for example, to enable one or more shoulders, grooves, etc. to be cut into the wall.
As an example, an assembly may include a seal arrangement that includes a gland formed in part by a metal seal element, a polymer seal element, etc. (e.g., where a thin-wall may be defined with respect to a thick-wall and flanged joints such as, for example, those found in a bellows subassembly or a pothead of an ESP).
As an example, a joint may be an interface between a thick-wall part and a thin-wall part. In such an example, the thin-wall part may be too thin for an appropriate shoulder or groove to be cut into it to form a gland. In such an example, the wall may be sufficient for shallower features such as threads and, for example, one or more retainer ring grooves. As an example, a thick-wall part may be a male part and a thin-wall part may be a female part; noting that such an approach may apply, for example, to a thin-wall male part and a thick-wall female part, to two thin-wall parts, etc. As an example, a female part may be a housing of an ESP pump, motor, protector, gauge or other ESP-related component. Examples of thin-wall male parts may include shaft tubes, breather tubes, bag frames, and various adapters.
As an example, a metal seal element and/or a polymer seal element may lack sufficient elasticity for stretching, for example, for stretching over a full-diameter male part for assembly into a groove in the male part. In such an example, the seal element may be assembled onto a step or shoulder on a thick-wall male part where a corresponding step or shoulder exists on a mating female part (e.g., that is provided to complete a gland and contain the seal element). As an example, where the wall of the female part is too thin for a corresponding step or shoulder to be cut in it, closure of a gland may be facilitated by including a ring (e.g., metal, alloy, composite, etc.), which may be referred to as, for example, a structural ring.
As an example, a structural ring may be a component that may be positioned at or near a joint formed by two or more components. As an example, a structural ring may provide for gland formation, for example, in combination with one or more seal elements.
As an example, a structural ring may include threads along an inner diameter, along an outer diameter or along an inner diameter and along an outer diameter. For example, a structural ring may thread into threads of a female part and into threads of a male part where the structural ring may form, at least in part, a gland. In such an example, the gland may include a seal element or seal elements that form a seal (e.g., between the male and female parts).
As an example, a structural ring may be configured to interference fit with respect to a component. For example, an interference fit may be a press-fit, a thermal fit or other type of interference fit. As to a thermal fit, a process may include heating and/or cooling one or more components and then allowing the one or more components to reach an equilibrium temperature. For example, a female component may be heated to cause thermal expansion and a structural ring may be seated with respect to an inner diameter of the heated female component. In such an example, upon cooling the structural ring may be located via forces exerted during contraction of the female component as it cools to an equilibrium temperature. As an example, a structural ring may be heated and/or cooled, for example, depending on whether it is to be positioned with respect to a male component (e.g., outer diameter) or a female component (e.g., inner diameter).
As an example, a structural ring may be held in position via a compressive force, a tensile force or both compressive and tensile forces. As an example, forces may be applied to a structural ring upon rotation (e.g., for threads, etc.). As an example, a structural ring may be made of a material selected based in part on tensile and/or compressive characteristics of the material.
As an example, ductility may describe a material's ability to deform under tensile stress while malleability may describe a material's ability to deform under compressive stress. Ductility and malleability may be described as being mechanical properties that are aspects of plasticity, for example, that may define the extent to which a material can be plastically deformed without fracture.
As an example, a structural ring may be configured for assembly to an exterior of a male part. In such an example, the ring may supply a second shoulder to complete a gland for a seal (e.g., to contain a seal element or seal elements), for example, where a first shoulder is supplied by the male part. In such an example, a housing may be configured as a female part, for example, with a wall having a surface disposed at an inner diameter. In such an example, the housing may be assembled over the ring. As an example, the structural ring may be joined to the male part by threads, screws, pins, welds, solder, retainer rings, its own elasticity (e.g., in the case that the ring itself is a retainer ring), circumferential keys, interference fit or other mechanical means and, for example, the female part may be threaded either to the male part or to the ring.
As an example, a structural ring may be configured for assembly to an interior of a female part. For example, such a ring may supply a shoulder in the female part to complete a gland for a seal (e.g., to contain a seal element or seal elements). In such an example, the ring may be joined to the female part by threads, screws, pins, welds, solder, retainer rings, its own elasticity (e.g., in the case that the ring itself is a retainer ring), circumferential keys, interference fit or other mechanical means and, for example, either the female part or the ring may be threaded to the male part.
As an example, a structural ring may be configured for assembly to an interior of a female part. For example, such a ring may supply a shoulder against which a male part may bear during assembly of the male and female parts by threading for instance (e.g., optionally in lieu of an arrangement in which the end of the female part bears against a shoulder on the male part). As an example, such a ring may incorporate a gland for a seal or, for example, a gland may be formed at an end of the female part and a shoulder of the male part. As an example, a ring may be joined to a female part by threads, screws, pins, welds, solder, retainer rings, its own elasticity (e.g., in the case that the ring itself is a retainer ring), circumferential keys, interference fit or other mechanical means and, for example, either the female part or the ring may be threaded to a male part.
As an example, a structural ring may be configured for assembly to an exterior of a female part, for example, to supply thickness to a wall of the female part (e.g., to effectively increase structural wall thickness of an assembly). In such an example, a structural ring may allow a shoulder to be cut in an interior surface of a housing to complete a gland for a seal (e.g., to contain a seal element or seal elements).
As an example, a structural ring may allow for cutting a groove in an end of a housing, for example, to form a face gland. As an example, in the case of a polymer seal (e.g., or metal and polymer seal) that can be sufficiently deformed for insertion into a groove without damage, a structural ring may add sufficient wall thickness to allow for a groove to be cut in an interior of a female part.
As an example, a ring may be used to stiffen a wall, for example, to help prevent distortion due to torque or welding during assembly or due to loads applied during installation and operation, which may, for example, compromise sealing function of one or more metal and/or polymer seals (e.g., formed in part by one or more metal and/or polymer seal elements).
As an example, a ring may be joined to an exterior or an end of a female part by threads, screws, pins, welds, solder, retainer rings, its own elasticity (e.g., in the case that the ring itself is a retainer ring), circumferential keys, interference fit or other mechanical means. As an example, a ring may be formed integral to an end of a thin-wall tube, for example, by upset forging. As an example, a female part or a ring may be threaded to a male part.
As an example, an assembly may include two thin-wall parts, for example, where two structural rings (e.g., one or two of those described in examples herein) may be utilized, for example, one for a male part and one for a female part.
As shown, the structural ring 315 is located axially by the two snap rings 317 and 319 that are seated partially in respective annular grooves in an interior surface of the female part 314. The structural ring 315 may include a notch, for example, that forms an annular shoulder of the structural ring 315. As shown, the snap ring 319 may be seated with respect to such a notch. As an example, a snap ring may be a piston ring.
As an example, the seal element 311 may be a seal element marketed as a James Walker Springsele® seal element. The James Walker Springsele® seal element includes anti-extrusion springs, for example, configured as toroidal-wound springs of corrosion resistant material. Such material may be, for example, one or more of the following stainless steel to BS EN 10270-3-1.4401 (formerly Grade 316 S42) or nickel-based Alloy 600-UNS N06600. As another example, a seal element may be a James Walker Teesele® seal element, which may include anti-extrusion element(s) precision machined in virgin polyether-etherketone (PEEK® 450G from Victrex plc.), which is a rigid thermoplastic engineering polymer resistant to chemical attack and wear at high temperatures (e.g., a Teesele® seal may be configured as an elastomeric seal using a rigid polymer). As an example, one or more other materials may be available (e.g., various filled grades of PTFE).
As an example, the seal element 311 may be an extrusion-resistant double-acting seal element, optionally including hydrogenated nitrile elastomer (e.g., HNBR) or fluoroelastomer (e.g., FKM). Such a seal element may include one or more toroidal anti-extrusion springs.
As an example, an elastomeric material can have a very high bulk modulus, which makes it substantially incompressible. As an example, for installation of a Springsele® seal element, the elastomeric element may be deformed slightly in its “housing” to give a predetermined level of radial seal compression. In such an example, the resulting force provides positive fluid sealing at zero system pressure. When system pressure is applied, the elastomeric component may deform further but, because of an initial squeeze, the sealing force may exceed the force exerted on the seal by the fluid. Such deformation may move a Springsele® anti-extrusion spring into a clearance gap of a housing (e.g., on a low pressure side). With a Teesele® seal element, an anti-extrusion ring may be activated by system pressure. Such action may, for example, act to prevent extrusion (e.g., at increased pressures).
As an example, a seal element may include one or more elastomers. As an example, such a seal element may include a last-O-Lion® 101 seal element that includes an HNBR elastomer, which may provide suitable mechanical strength and wear-resistant properties. Such an elastomer may provide resistance to various oilfield chemicals such as, for example, H2S and amine corrosion inhibitors. Such a grade of elastomer may be qualified to the Norsok M-710 standard, which may cover both rapid gas decompression (RGD) resistance and sour gas (H2S) ageing tests.
As an example, a seal element may include a FR58/90-fluoroelastomer (FKM), based on DuPont™ Viton® B. This elastomer may exhibit suitable chemical and thermal properties and may be qualified to the Norsok M-710 standard, which may cover both rapid gas decompression (RGD) resistance and sour gas (H2S) ageing tests.
As an example, a Springsele® seal element may operate with higher levels of groove fill than an O-ring, noting that high groove fill can enhance RGD resistance. As an example, a Springsele® seal element may be configured to be stretch-fitted into a groove for external applications, and compression-fitted into a groove for internal applications. As an example, a Teesele® seal element may use one or more rigid plastic back-up rings. As an example, a Springsele® seal element may be configured with a higher level of squeeze than an O-ring, which may help to improve low temperature sealing performance and RGD resistance (e.g., optionally catering to housing offset in duties with particular extrusion clearances).
As an example, a seal element may be installed in a blind recess, for example, an integral anti-extrusion spring in a Springsele® seal element may act to reduce risk of the seal element becoming dislodged or damaged during assembly. As for the Teesele® seal element, one or more anti-extrusion elements thereof may be bi-directional, for example, to help prevent incorrect installation (e.g., incorrect orientation).
As an example, a part may include a chamfer to facilitate positioning of a seal element. For example, where a Springsele® seal element may be subjected to stab-in, a lead-in chamfer of about 15 to about 30 degrees may be provided (e.g., as machined into a part, for example, as part of a groove).
As to the seal 318, it can include (e.g., be formed in part by) the seal element 313 as a metal C-ring, the snap rings 317 and 319 and the structural ring 315 as a gland ring. As shown, the C-ring 313 is oriented facing axially to the right, which is toward the interior of the female part 314. In such an arrangement, pressure from within the housing may act on the C-ring 313 to expand the C-ring 313 against the parts 312 and 314 to enhance sealing. As an example, as the closed side of the C-ring 313 may be facing the elastomer seal 311, high pressure that may develop between the seals, due to for instance thermal expansion of fluid, may be relieved, for example, past the C-ring 313 before the pressure reaches a level sufficient to extrude the elastomer seal 311.
Also shown in the assembly 310 is a port 320 that may be sealed via a plug 322, which may include an elastomer seal element and a non-elastomer seal element. As an example, a small ring that may include lead (Pb) may be placed on the plug 322 and upon application of compression by the plug 322, it may deform and seal the port 320.
As shown, the port 320 extends to a lower portion 321 that is in fluid communication with a passage 323 that extends to an opening 324 at a surface of the part 312 where the opening 324 is at a location between the seal 316 and the seal 318. The port 320 may be used for any of a variety of purposes, for example, it may be used for testing sealing, pressure loading, etc. For example, pressure may be applied at the port 320 using fluid where the pressure is communicated to the opening 324 via the passage 323, which may be a bore in the part 312. In such an example, the pressure may be transferred to the seal 316 and/or to the seal 318. As an example, if the seal 316 is insufficient to withstand the applied pressure, fluid may be detected at an external joint interface between the parts 312 and 314. As an example, seal integrity may be determined by measuring a change in an applied pressure. For example, if pressure is applied at the port 320 and the pressure drops, the drop in pressure may be an indication that one of the seals 316 and/or 318 experienced leakage. As an example, one or more of the example systems described herein may optionally include a port, for example, with a passage to communicate fluid pressure to a location within a system for purposes of testing integrity of one or more seals.
As shown in
As shown in
In the assemblies 310, 330 and 350 of
In
In
As an example, a system may include a double threaded gland ring such as, for example, the gland ring 515 of
As an example, a part may be provided in a preassembled manner such that it includes a gland ring. For example, the gland ring 515 may be provided preassembled to the part 512 or preassembled to the part 514. As an example, a seal element may be provided preassembled to the part 512 or preassembled to the part 514, for example, where upon joining the parts 512 and 514, the seal element forms a seal by being positioned in a gland formed in part by a structural element such as the gland ring 515.
As to the assembly 530, it includes a male part 532, a female part 534 and a seal 538. As an example, the male part 532 may be a head, base or body and, as an example, the female part 534 may be a housing (e.g., a thin-walled housing). As shown, the part 534 abuts a shoulder of the part 532 (e.g., at an annular face of the shoulder of the part 532 and at an end face of the part 534). As an example, the seal 538 may include a C-ring 533 (e.g., or an E-ring, etc.), a gland ring 535 (e.g., a structural ring) and a snap ring 537. As shown, the seal 538 includes the gland ring 535 with an inner diameter chamfer that matches a chamfer of the part 532 and the snap ring 537 seats in a groove of the part 532 to axially limit the position of the gland ring 535. As shown, a gland may be formed between a shoulder of the part 532 and the gland ring 535. Also shown in
As to the assembly 630, it includes a male part 632, a female part 634 and a seal 638. As an example, the male part 632 may be a head, base or body and, as an example, the female part 634 may be a housing (e.g., a thin-walled housing). As shown, the part 634 abuts a shoulder of the part 632 (e.g., at an annular face of the shoulder of the part 632 and at an end face of the part 634). As an example, the seal 638 may include a C-ring 633 (e.g., or an E-ring, etc.) and a gland ring 635 (e.g., a structural ring). As shown, a gland is formed between a shoulder of the part 632 and the gland ring 635, which may be positioned via an interference fit (e.g., where the free standing OD of the gland ring exceeds an inner diameter of the part 634. As shown, to axially locate the gland ring 635, a shoulder exists along the inner diameter of the part 634. Also shown are matching threads of the parts 632 and 634, for example, to threadably join the parts 632 and 634. As an example, the assembly 610 or the assembly 630 may optionally include a seal element such as an elastomeric seal element (e.g., a Springsele® seal element), for example, as shown in various figures herein.
As to the assembly 730, it includes a male part 732, a female part 734 and a seal 738. As an example, the male part 732 may be a head, base or body and, as an example, the female part 734 may be a housing (e.g., a thin-walled housing). As shown, a C-ring 733 (e.g., or an E-ring, etc.) is disposed in a gland formed by a shoulder of the part 734 and a shoulder of the part 732. In such an example, the gland is disposed axially to one side of matching threads for joining the parts 732 and 734. At another side, a gland ring 735 is positioned, for example, via outer diameter threads that match the inner diameter threads of the part 734. In such an example, the gland ring 735 may be threaded into the part 734 until it abuts a shoulder of the part 734. As an example, the C-ring 733 (e.g., or an E-ring, etc.) may be positioned on the part 732, for example, with the open side facing radially inwardly toward the z-axis to be energized by high internal pressure or the open side may be facing radially outward to relieve high internal pressure between C-ring 733 and an elastomer seal, if present. As an example, one or both of the parts 732 and 734 may be rotated to bring the parts 732 and 734 together to reduce the size of the gland (e.g., to form the gland) that houses the C-ring (e.g., or an E-ring, etc.). In such an example, the gland ring 735 may be load bearing as it is positioned between a shoulder of the part 734 and an end of the part 732. As an example, the assembly 710 or the assembly 730 may optionally include a seal element such as an elastomeric seal element (e.g., a Springsele® seal element), for example, as shown in various figures herein.
As shown, the part 812 includes a shoulder with a radial width sufficient to accommodate an end of the part 814 as well as a gland ring 815 (e.g., a structural ring) where the end of the part 814 is disposed between the part 814 and the gland ring 815. At an end of the gland ring 815, a weld may be made between the part 814 and the gland ring 815. As an example, the seal 818 may include a C-ring 813 (e.g., or an E-ring, etc.). As shown, the seal 818 includes a gland formed between a shoulder of the part 812 and a shoulder of the part 814, which is located at an end of matching threads of the parts 812 and 814, for example, to threadably join the parts 812 and 814. The C-ring 813 (e.g., or an E-ring, etc.) may be positioned on the part 812, for example, with the open portion facing generally in a direction from which fluid may be driven by pressure from a space defined in part by the part 814. In such a manner, the C-ring 813 (e.g., or an E-ring, etc.) may respond to pressure to enhance sealing. As to assembly, the gland ring 815 may be positioned about an OD of the part 814 and then after joining the parts 812 and 814, the gland ring 815 may be welded (e.g., or soldered) to the part 814 and optionally to the part 812. In such an example, the gland ring 815 may add thickness to the wall, particularly along a portion that coincides, at least in part, with the chamber (e.g., gland) that houses the C-ring 813 (e.g., or an E-ring, etc.) as the shoulder of the part 814 acts to thin the thickness of the part 814. As an alternative example, the part 814 may include a face rather than a shoulder and the gland ring 815 may form a wall of the annular chamber (e.g., gland) that houses the C-ring 813 (e.g., or an E-ring etc.). In such an example, welding of the gland ring 815 to the part 814 and optionally to the part 812 may provide additional sealing capacity.
As to the assembly 830, it includes a male part 832, a female part 834 and a seal 838 that includes multiple seals, for example an allowably rigid seal element 833-1 (e.g. a metal C-ring or E-ring) and a flexible seal element 833-2 (e.g. elastomeric) that may be folded to avoid damage during insertion into an internal groove. As an example, the male part 832 may be a head, base or body and, as an example, the female part 834 may be a housing (e.g., a thin-walled housing). As shown, each seal element 833-1 and 833-2 is disposed in a respective gland where one gland is formed by a shoulder of the part 834 and a shoulder of the part 832 while the other gland is formed by an annular groove in the part 834. As shown, the glands are disposed axially to one side of matching threads for joining the parts 832 and 834. At another side, a forged upset end may provide additional thickness 835 to the part 834, which is available for forming chambers (e.g., glands) for the rings 833-1 and 833-2. As an example, one of the seal elements 833-1 or 833-2 may be positioned on the part 832, for example, with an open side (e.g., of a C-shape, an E-shape, etc.) facing radially inwardly toward the z-axis and the other of the seal elements 833-2 or 833-1 may be positioned in the part 834 and then the parts 832 and 834 rotated to bring the parts 832 and 834 together to reduce the size of the end chamber (e.g., to form the chamber or gland) that houses one of the seal elements 833-1 or 833-2. As an example, the assembly 810 or the assembly 830 may optionally include a seal element such as an elastomeric seal element (e.g., a Springsele® seal element), for example, as shown in various figures herein.
As shown, a shoulder of the part 912 and a gland ring 915 located by snap rings 917 and 919 fit into grooves of the part 914 form a chamber (e.g., gland) for a C-ring 913 (e.g., or an E-ring, etc.). Matching threads allow the parts 912 and 914 to be threadably connected and an external ring may be provided optionally as a load bearing ring, for example, which includes threads along its inner diameter that threads to threads along an outer diameter of the part 912. As an example, a weld (e.g., or solder) may be provided between the load-bearing ring 916 (e.g., a structural ring) and the part 912. In such an example, the weld may provide for additional sealing capacity.
As to the assembly 930, it includes a male part 932, a female part 934 and a seal 940. As an example, the male part 932 may be a head, base or body and, as an example, the female part 934 may be a housing (e.g., a thin-walled housing). As shown, a load-bearing ring 935 (e.g., a structural ring) may include outer diameter threads that match inner diameter threads of the part 934 and it may include a face that abuts an end of the part 932. As an example, the load-bearing ring 935 may be threaded into the part 934 and then the part 932 threaded into the part 934 until it abuts the load-bearing ring 935 (e.g., optionally with a specified torque). As shown, the part 932 includes a shoulder that can receive an end of the part 934. At the interface between these two parts, as an example, a sweat solder joint may be formed by sweating solder into the interface. Such solder may provide for additional sealing capacity.
As to the assembly 950, it includes a male part 952, a female part 954, a seal 958, and a seal 960. As an example, the male part 952 may be a head, base or body and, as an example, the female part 954 may be a housing (e.g., a thin-walled housing). As shown, the seal 958 may include a ring 953 (e.g., O-ring, C-ring, E-ring, etc.) disposed in a groove of the part 952 where a chamber (e.g., gland) is formed along with a surface of the part 954. As shown, the seal 958 is located axially to one side of matching threads of the parts 952 and 954, which can be used to join the parts 952 and 954. As shown, the part 952 includes a shoulder that can receive an end of the part 954. At an interface between these two parts, a lock-weld may be formed. As an example, each of the parts may include a chamfer or other feature that may assist in forming the lock-weld. As an example, an external ring 955 (e.g., cylindrical wall or sleeve as a structural ring) may be positioned over the lock-weld to provide some protection (e.g., or strength) to the lock-weld or more generally to the joint between the parts 952 and 954. As to the seal 960, it may be formed as a sweat solder seal by sweating solder between the external ring 955 (e.g., cylindrical wall or sleeve) and the parts 952 and 954. Such solder may penetrate the interface and optionally cover the lock-weld, for example, to provide additional sealing capacity. As an example, the assembly 910, the assembly 930 or the assembly 950 may optionally include a seal element such as an elastomeric seal element (e.g., a Springsele® seal element), for example, as shown in various figures herein.
In the example of
As mentioned, a structural weld 1023 (e.g., non-sealing) may be formed at a location to one side of the weep hole; thereby making it a non-sealing weld as fluid would likely exit the weep hole rather than penetrate the weld. As shown, the weld is made at an interface between the part 1012 and the part 1014, for example, where the part 1012 includes a shoulder that abuts an end of the part 1014.
As an example, the test port 1011 may be sealed using a plug where one or more of an elastomer and non-elastomer may be used for sealing the test port 1011. As mentioned, an O-ring and a lead gasket may be used for sealing the test port 1011 along with a plug that includes threads that match threads of the test port 1011. In such an example, upon threading the plug into the test port 1011, the lead gasket may deform and form a seal to seal passage of fluid that may enter the passage 1027 (or residual fluid in the passage 1027 from testing) as driven by pressure inside the assembly 1010.
As to the assembly 1030, it includes a male part 1032, a female part 1034, a seal 1036, a seal 1038 and a seal 1043. As an example, the male part 1032 may be a head, base or body and, as an example, the female part 1034 may be a housing (e.g., a thin-walled housing). As shown in the assembly 1030, the seal 1043 may be a seal formed by molten material that has solidified (e.g., via welding, brazing, welding and brazing, etc.). Also shown in the assembly 1030, are threads 1045, which may be included as features (e.g., threads, bayonet, ring and grooves, etc.) that structurally join the male part 1032 and the female part 1034. In such an example, structural loads may be transferred, born, etc. by the threads 1045 (e.g., matching threads that include outer diameter threads of the male part 1032 and inner diameter threads of the female part 1034).
In the example of
As mentioned, the assembly 1030 may include the seal 1043 (e.g., a molten and solidified material seal). As shown, the seal 1043 is made at an interface between the part 1032 and the part 1034, for example, where the part 1032 includes a shoulder that abuts an end of the part 1034.
As an example, the test port 1031 may be sealed using a plug where one or more of an elastomer and non-elastomer may be used for sealing the test port 1031. As mentioned, an O-ring and a lead gasket may be used for sealing the test port 1031 along with a plug that includes threads that match threads of the test port 1031. In such an example, upon threading the plug into the test port 1031, the lead gasket may deform and form a seal to seal passage of fluid that may enter the passage 1047 (or residual fluid in the passage 1047 from testing) as driven by pressure inside the assembly 1030.
As to the assembly 1050, it includes a male part 1052, a female part 1054, a seal 1056, and a seal 1063. As an example, the male part 1052 may be a head, base or body and, as an example, the female part 1054 may be a housing (e.g., a thin-walled housing). As shown in the assembly 1050, the seal 1063 may be a seal formed by molten material that has solidified (e.g., via welding, brazing, welding and brazing, etc.). Also shown in the assembly 1050, are threads 1065, which may be included as features (e.g., threads, bayonet, ring and grooves, etc.) that structurally join the male part 1052 and the female part 1054. In such an example, structural loads may be transferred, born, etc. by the threads 1065 (e.g., matching threads that include outer diameter threads of the male part 1052 and inner diameter threads of the female part 1054).
In the example of
As mentioned, the assembly 1050 may include the seal 1063 (e.g., a molten and solidified material seal). As shown, the seal 1063 is made at an interface between the part 1052 and the part 1054, for example, where the part 1052 includes a shoulder that abuts an end of the part 1054.
As an example, the test port 1051 may be sealed using a plug where one or more of an elastomer and non-elastomer may be used for sealing the test port 1051. As mentioned, an O-ring and a lead gasket may be used for sealing the test port 1051 along with a plug that includes threads that match threads of the test port 1051. In such an example, upon threading the plug into the test port 1051, the lead gasket may deform and form a seal to seal passage of fluid that may enter the passage 1067 (or residual fluid in the passage 1067 from testing) as driven by pressure inside the assembly 1050.
As an example, an assembly may include a sealing weld where, for example, structural load may be carried by threads, bayonet, or other coupling mechanism (e.g., optionally at least in part via a structural ring, which may be a gland ring).
As an example, a seal weld may be smaller than a structural weld, which may, for example, result in less distortion (e.g., a structural weld may be stressed and include more material to handle such stress). In comparison, failure of a sealing weld may result in leakage while failure of a structural weld may result in loss of structural integrity of an assembly, which may be downhole (e.g., possibly hundreds of meters or more).
As shown in
As an example, an assembly may include a test port, for example, where the test port is in fluid communication with a passage that extends to an opening disposed between two seals where one of the seals may be a seal formed via welding, brazing or a combination of welding and brazing.
As an example, for less weldable materials that may involve post-weld heat treatment that may be undesirable as to a finished assembly, weld prep may be weld overlaid or added to by welding on a more weldable material and post-weld heat treated as a component before welding into an assembly. For example, a process may include buttering. As an example, buttering may include, prior to welding materials, applying “butter” to one or more faces where the “butter” may be a material such as, for example, an alloy, a metal, etc. (e.g., a filler material that may act as a buffer between the two parts to be joined).
As an example, a seal weld may be constructed in part from a softer material than may be used for a structural weld. In such an example, the softer material may optionally be more resistant to corrosion and/or cracking (e.g., compared to a harder material used for a structural weld). As an example, a structural weld may be made from a material or materials that provide for a structural function and a seal weld may be made from a material or materials that provide for a sealing function.
As an example, an assembly may include a seal weld and threads (e.g., that can join a male part and a female part) where the threads act to carry structural loads (e.g., carried by the male part and/or the female part). As an example, an assembly may include a seal weld and a non-welded structural joint. As explained with respect to the example assemblies 1030 and 1050 of
As an example, a seal may include an elastomer and metal or alloy. As an example, such a seal may be configured to reduce risk of seal extrusion, for example, up to a pressure differential of about 10,000 psi or more. As an example, such a seal may be used in conjunction with a non-elastomeric seal to seal an interface between components (e.g., parts) of an ESP. As an example, an elastomeric material may be defined having some properties akin to natural or synthetic rubber such that the material is able to resume its original shape when a deforming force is removed. For example, an elastomeric material may be characterized as having a low Young's modulus and high yield strain compared with other materials. As an example, an elastomeric polymer material may include amorphous polymers existing substantially above their glass transition temperature such that substantial segmental motion is possible.
Some examples of unsaturated rubbers that can be cured by sulfur vulcanization include natural polyisoprene: cis-1,4-polyisoprene natural rubber (NR) and trans-1,4-polyisoprene gutta-percha; synthetic polyisoprene (IR for Isoprene Rubber); polybutadiene (BR for Butadiene Rubber); chloroprene rubber (CR), polychloroprene, Neoprene, Baypren etc.; butyl rubber (copolymer of isobutylene and isoprene, IIR) Halogenated butyl rubbers (chloro butyl rubber: CIIR; bromo butyl rubber: BIIR); styrene-butadiene Rubber (copolymer of styrene and butadiene, SBR); nitrile rubber (copolymer of butadiene and acrylonitrile, NBR), also called Buna N rubbers; and hydrogenated Nitrile Rubbers (HNBR) Therban and Zetpol.
Some examples of saturated rubbers that cannot be cured by sulfur vulcanization include EPM (ethylene propylene rubber, a copolymer of ethylene and propylene) and EPDM rubber (ethylene propylene diene rubber, a terpolymer of ethylene, propylene and a diene-component); epichlorohydrin rubber (ECO); polyacrylic rubber (ACM, ABR); silicone rubber (SI, Q, VMQ); fluorosilicone rubber (FVMQ); fluoroelastomers (FKM, and FEPM) Viton, Tecnoflon, Fluorel, Aflas and Dai-El; perfluoroelastomers (FFKM) Tecnoflon PFR, Kalrez, Chemraz, Perlast; polyether block amides (PEBA); chlorosulfonated polyethylene (CSM), (Hypalon); and ethylene-vinyl acetate (EVA).
As mentioned, an elastomeric seal may include an elastomer such as NBR or FKM. As mentioned, such a seal may include another material such as, for example, a metal or an alloy. As an example, a Springsele® seal element may include an elastomer such as a NBR (e.g., HNBR) or an FKM.
As to examples of non-elastomeric seal materials, a metal, an alloy or a polymer may be substantially non-elastomeric. For example, polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that may be considered non-elastomeric (e.g., marketed as TEFLON® by E. I. du Pont de Nemours and Company, Wilmington, Del.). As an example, a non-elastomeric seal material may include polyether ether ketone (PEEK). PEEK is a semi-crystalline thermoplastic with mechanical and chemical resistance properties that may be retained to high temperatures. The Young's modulus is about 3.6 GPa and its tensile strength is about 90 to about 100 MPa. PEEK has a glass transition temperature at around 143 degrees C. (289 degrees F.) and melts around 343 degrees C. (662 degrees F.). PEEK is not traditionally a shape memory polymer; however, recent advances in processing have allowed shape memory behavior in PEEK with mechanical activation. Also, for example, introduction of covalent crosslinks into a semi-crystalline PEEK matrix may disrupt the crystal structure of aromatic polymer chains to result in a formation of amorphous and crosslinked polymeric substance that may exhibit rubbery (e.g., elastomeric) properties at high temperatures. Thus, as an example, as to an elastomeric material, it may include a substance that may be considered non-elastomeric. As an example, a seal akin to a Teesele® seal element may be configured using a material such as PEEK and optionally another material (e.g., where PEEK is a matrix that includes the other material to alter its properties along a scale from non-elastic to elastic).
As an example, a seal component may include a coating. For example, a C-ring may be coated with a material that is applied to a C-ring core. For example, a C-ring may include a hard core with a softer coating. As an example, a coating may include silver, which may be soft for conforming to contacting parts and resist galling (e.g., adhesive wear and transfer of material between metallic surfaces), for example, in response to force. As an example, an E-ring may be used in addition to or as an alternative to a C-ring. As an example, a seal may include an E-ring.
As an example, a seal component may be a gland ring, which is substantially non-elastomeric (e.g., substantially rigid). As an example, a gland ring may include one or more sets of threads. For example, a gland ring may include inner diameter threads, outer diameter threads or both inner diameter threads and outer diameter threads, which may optionally be of different characteristics (e.g., spacing, angle, depth, etc.). As an example, a gland ring may include another locating mechanism, for example, consider prongs for receipt by sockets. In such an example, prongs may be configured with respect to an ID, an OD or both an ID and an OD. Alternatively, a gland ring may include a socket for receipt of a prong or sockets for receipt of prongs. As an example, a gland ring may include one or more features of a bayonet locating mechanism. As an example, a gland ring may be split ring or a continuous ring. As an example, as a split ring, a gland ring may include one or more overlapping portions. As an example, a gland ring may be spiral, for example, such as a helical spiral constructed of a substantially flat ribbon of material (e.g., with more than one turn).
As an example, an assembly may include one or more features for axially locating a gland ring. For example, one or more snap rings may be provided for axially locating a gland ring with respect to a part. In such an example, a snap ring may snap into a groove of a part at a particular axial location such that the gland ring abuts the snap ring to thereby axially locate the gland ring. As mentioned, features such as threads, prongs, sockets, etc., may act to axially locate a component such as a gland ring.
As an example, a gland ring may be configured integral or pre-attached to an elastomer and/or a non-elastomer seal element, for example, optionally for assembly in a system (e.g., an ESP) coincident with assembly to form a seal. For example, a snap ring or other retainer ring may be molded into a component or snapped to it by elastic or plastic deformation of either the gland ring or a seal element. As an example, such a snap or retainer ring may serve as a gland ring in the assembly that forms, at least in part, a gland.
As an example, a housing of an ESP component may have a diameter of the order of about 7 inches. For example, the parts 201, 314, 334, 354, 414, 434 and 454 (e.g., or parts in other drawings) may have an outer diameter of about 7 inches. Given such a dimension, approximate dimensions of seals may be determined, as examples. An ESP may have, for example, an outer diameter in a range of about 3 inches to about one foot. In such an example, components of
As an example, a seal or seal component may include features that allow for use of a spanner wrench. For example, as shown in the assembly 350 of
As an example, a seal may include a seal component that fits a part using swaging, flare fitting, compression fitting, etc. As an example, such a seal component may include two diameters along an axial dimension such that the seal component includes a conical shape. As an example, a gland ring may be a cone ring with a tapered end where the cone portion is located between two parts and where upon axial movement of the two parts toward each other the cone portion experiences force. As an example, a seal component may be slip fit. As an example, a seal component may be interference fit.
As an example, where a seal includes a C-ring (e.g., or E-ring, etc.) and a gland ring disposed in the same chamber (e.g., annular region that forms a gland), the radial height of the gland ring may be less than that of the C-ring such that expansion of a load on the C-ring provides for contact stress.
As an example, welding may be applied to form a weld. As an example, consider a process where a joint is between two cylindrical parts with a close fit and the joint has an axial length. In such an example, the joint may be sweat soldered by heating the joint until the solder flows into it by capillary action (e.g., rather than heating the solder with the torch).
As an example, for solder that is about 95 percent tin to about 5 percent silver, a higher fatigue strength and lower leaching in water may be provided when compared to lead solder.
As an example, heat generated by welding may occur for a brief time and may be controlled by chilling and by placing the welds a sufficient distance from any sensitive components (e.g., polymer, elastomer, etc.). As an example, a method may include pre-heating and post-weld heat treatment. Such heat treatment may be implemented to safely weld high strength low alloy steels and alloy steels that may be used for housings, heads and bases, for example, with minimal risk of subsequent cracking. Such treatment may be applied in a manner that avoids risk of damage to one or more components (e.g., of an ESP).
A description of some example aspects of an example of a solder joint follows. As an example, an effective solder joint may be made by designing a joint with a few thousandths of an inch of clearance. Before applying solder, the joint may be preheated to the melting point of the solder. The solder may then be applied to the heated parts so that it melts and fills the gap by capillary action. As an example, making of a solder joint may have poor adhesion of the solder where the joint was made cold. Where a joint is heated with a torch to less than the melting point of the solder, the solder may stick and build up, rather than melt and run out of a groove. As an example, rather than applying solder to a joint, solder may be inserted into a flame and dripped into the joint, where it may subsequently solidify.
Various aspects of a solder joint based on sweat joints are described below (e.g., consider sweat joints as used in copper plumbing for water pipes). As an example, a joint may exist between two cylindrical parts with a controlled clearance that can provide for capillary action with molten solder (e.g., a molten material). As an example a joint may be long enough to generate sufficient strength to resist stress and strains on the joint. As an example, a joint may be sweat soldered by heating the joint until solder flows into it by capillary action (e.g., not by heating the solder directly). As an example, a joint may be formed between the ID of one part and the OD of another part. As an example, the two parts may be screwed together to form a joint where one or more openings may be provided in an exterior of an outer one of the parts for introduction of solder (e.g., material) into the joint. As an example, alternatively (e.g., or additionally), an internal load-bearing shoulder may be provided to preserve a gap in an external joint between the two parts through which solder may be introduced into the joint (e.g., which may be a cylindrical joint). As an example, a joint may be formed between each of two parts being joined and a third part such as a sleeve with a controlled clearance for sweat soldering. As an example, solder may be chosen for high fatigue strength, low creep and low leaching. For example, solders containing silver and tin may meet such specifications. As an example, one such solder is approximately 95 percent tin and approximately 5 percent silver.
As to a welded joint, as an example, intermittent welding may be used in one or more ESP joints for preventing joints from unscrewing, for example, due to acceleration of the motor and pump (e.g., due to torque, etc.). In such an example, an ESP may include structural threads and seals along with the welding, for example, such that three overlapping systems may be used to cover functions of structural integrity and sealing integrity.
As an example, continuous welding may be used in ESPs for dual roles of structure and sealing, for example, without threads; however, such an approach may impose some conditions on the weld: (a) as an example, a weld defect that compromises sealing may be more common than one that compromises a desired strength; and (b) as an example, it may be desirable to make a seal weld continuously around a circumference because the start and the end of a weld may be prone to defects that could possibly result in a leak. However, as an example, cumulative heat of continuous welding may cause damage to internal components.
As an example, for an assembly, a welded joint may be provided that serves a structural purpose, rather than sealing. In such an approach, welding may fulfill one or more structural specifications, while other seals may fulfill a desired sealing function. As an example, a weld can be made intermittent in space and/or intermittently in time to limit the temperature rise on internal components, especially the elastomer seals. As an example, a welded joint may be made with a reduction in wall thickness of a housing, in part, by use of threads or grooves, thus maximizing the pressure capacity of the housing. As an example, a joint may be sealed with one or more other means, including elastomer seals, metal seals, polymer seals and combinations of different seals. As an example, an assembly may also use one or more gland rings, test ports and other features mentioned elsewhere herein, though in various examples, such feature(s) may be optional.
As an example, in case that a weld covers a full circumference of a housing, it may create a sufficiently effective seal to mask a leak in another seal during leak testing. In such an instance, a weep hole between the seal and the weld may be provided to readily reveal any leakage. This may also reduce the stress at the weld by reduction of pressure hoop stress.
As an example, a temperature rise during welding may be controlled by optimized welding parameters, intermittent welding, internal cooling by flow of liquid or gas, external cooling by flow of liquid or gas, solid heat sink.
As an example, a weld may use a variety of welding methods, including gas metal arc welding, metal inert gas welding, tungsten inert gas welding, submerged arc welding, gas welding, electric resistance welding, wire feed, laser welding and, for example, one or more other known welding methods. As an example, a weld may be inspected by a variety of methods, including radiography, ultra sound, magnetic flux, dye penetrant, mechanical loading, etc.
As an example, a seal element may be an elastomer James Walker Springsele® seal element that includes integral metal or alloy support. Such a seal element may be implemented as part of an outermost seal while an innermost seal may be a non-elastomeric seal that includes a non-elastomeric seal element. As an example, an inner seal element may be a radial metal C-ring set with respect to a split gland. As an alternative, for example, an inner seal element may be a spring loaded polymer lip seal element.
As mentioned, an assembly may include a port, for example, with a passage that leads to a location between seals where the port may be plugged with a plug, for example, optionally including a metal seal element and an elastomer seal element.
As an example, an elastomer seal may be more forgiving of surface finish, dirt, corrosion of the sealing surface and movement, yet some elastomers may be subject to deterioration due to heat, chemicals and decompression. Also, as an example, an elastomer seal element may undergo changes in dimensions and hardness over wide temperature cycles that can cause leakage or damage. As an example, a metal seal may be resistant to heat, chemicals, decompression, temperature changes, etc. However, as an example, it may be sensitive to surface finish, dirt, corrosion of the sealing surfaces and movement. As an example, a polymer seal, such as spring loaded PTFE lip seals, may lie somewhere in-between as to such issues. As an example, a PTFE lip seal may be implemented in an assembly, for example, if a metal seal proved to be too sensitive. As an example, a lip seal may be assembled in a groove with a low outer shoulder instead of a full split gland.
As an example, an assembly may include redundant seals. As an example, a port may allow for testing, for example, using a high pressure that is applied via the port and where an ambient pressure is atmospheric pressure. As an example, after testing, a test port may be cleaned (e.g., of oil, etc., with an absorbent material, compressed air, etc.). A test may include permeation of high pressure gas in-between followed by decompression of the environment outside.
As an example, a partial solution to high pressure may be a pressure relieving seal. For example, polymer lip seals and metal C-rings can both relieve in one direction, though at different pressures. For instance, this can be used to relieve expansion of lubricant trapped between the seals, for example, if not cleared from a test port.
As an example, a test port may allow for verification that two seals are holding at a time of a test. As an example, a plug may plug a test port. Such a plug may include redundant metal (e.g., or alloy) and elastomer seals (e.g., consider a lead (Pb) gasket and an O-ring). As an example, a Springsele® seal element may be provided to seal a test port, for example, using a plug. As an example, as a test port may be considered a leak path, testing may proceed from outside an assembly, for example, so that if it leaks it bypasses an outer seal and not an inner seal. Testing from outside an assembly may permit testing on a finished assembly.
As an example, a submersible assembly can include a male part that includes an outer diameter; a female part that includes an inner diameter; an elastomeric seal element disposed between the male part and the female part; and a non-elastomeric seal element disposed between the male part and the female part. As an example, such an assembly may be a submersible pump. As an example, such an assembly may be an electric submersible pump. As an example, a submersible assembly may be positionable in an environment that includes fluid where a male part and a female part form a joint and where one or more seals are exist (e.g., optionally formed by joining the male part and the female part) that act to reduce flow of the fluid into at least a portion of the submersible assembly (e.g., a motor housing portion, a protector portion, a sensor portion, etc).
As an example, a submersible pump can include a male part that includes an outer diameter; a female part that includes an inner diameter; an elastomeric seal element disposed between the male part and the female part; and a non-elastomeric seal element disposed between the male part and the female part. In such an example, the submersible pump may further include a gland ring that, at least in part, defines a gland for the elastomeric seal element; a gland ring that, at least in part, defines a gland for the non-elastomeric seal element; a gland ring that, at least in part, defines a gland for the elastomeric seal element and a gland ring that, at least in part, defines a gland for the non-elastomeric seal element; or a gland ring that, at least in part, defines a gland for the elastomeric seal element and that, at least in part, defines a gland for the non-elastomeric seal element.
As an example, a male part can include threads, a female part can include threads or a male part can include threads and a female part can include threads. In such an example, the male and female parts may be parts of an assembly that includes a gland ring that includes threads that match threads of the male part, that match threads of the female part or that match threads of the male part and that match threads of the female part. In such an example, the threads of the gland ring may include threads along an outer diameter of the gland ring and threads along an inner diameter of the gland ring. For example, threads along an outer diameter of a gland ring may match threads along an inner diameter of a female part and threads along an inner diameter of a gland ring may match threads along an outer diameter of a male part.
As an example, a submersible pump may include a male part that includes threads along an outer diameter, a female part that includes threads along an inner diameter where the threads of the male part and the threads of the female part include matching threads. In such an example, an elastomeric seal element may be disposed axially on one side of the matching threads and a non-elastomeric seal element may be disposed axially on another side of the matching threads.
As an example, a submersible pump may include an elastomeric seal element that includes an elastomeric material and a non-elastomeric anti-extrusion component.
As an example, a submersible pump may include a non-elastomeric seal element that is or includes a C-ring, an E-ring or a spring-loaded polymeric lip seal element. In such an example, the submersible pump may include a gland ring disposed axially to an open side of the C-ring, the E-ring or the spring-loaded polymeric lip seal element.
As an example, a submersible pump may include a snap ring that axially locates a gland ring with respect to a male part of the submersible pump, with respect to the female part of the submersible pump or with respect to a male part of the submersible pump and with respect to a female part of the submersible pump.
As an example, an elastomeric seal element may be disposed between a male part of a submersible pump and a female part of the submersible pump where the elastomeric seal element includes metal or alloy that supports elastomeric material. In such an example, the metal or the alloy may include a toroidal-wound spring shape.
As an example, a submersible pump may include a male part that includes an annular groove dimensioned for receipt of an elastomeric seal element, an annular groove dimensioned for receipt of a non-elastomeric seal element or annular grooves dimensioned for receipt of seal elements.
As an example, a submersible pump may include an elastomeric seal element that is a non-extrudable elastomeric seal element rated to a pressure differential of at least about 10,000 psi.
As an example, a seal element may include a core and a coating disposed on the core. For example, a non-elastomeric seal element may include a core that is coated with a material (e.g., a coating).
As an example, a submersible pump may include a port and a passage extending from the port. In such an example, the passage may include an opening disposed axially between an elastomeric seal element and a non-elastomeric seal element. In such an example, pressure may be applied at the port where such pressure is communicated fluidicly via the passage, for example, to test a seal or seals (e.g., as formed in part by the elastomeric seal element and/or the non-elastomeric seal element). As an example, a submersible pump may include a plug that can be received by a port to seal the port. In such an example, the plug may include, as a sub-assembly, a seal element or seal elements (e.g., a lead (Pb) washer, an O-ring, etc.).
Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. §112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words “means for” together with an associated function.
Claims
1. A submersible pump comprising:
- a male part that comprises an outer diameter;
- a female part that comprises an inner diameter;
- an elastomeric seal element disposed between the male part and the female part; and
- a non-elastomeric seal element disposed between the male part and the female part.
2. The submersible pump of claim 1 further comprising a gland ring that, at least in part, defines a gland for the elastomeric seal element.
3. The submersible pump of claim 1 further comprising a gland ring that, at least in part, defines a gland for the non-elastomeric seal element.
4. The submersible pump of claim 1 wherein the male part comprises threads, the female part comprises threads or the male part comprises threads and the female part comprises threads.
5. The submersible pump of claim 4 further comprising a gland ring that comprises threads that match threads of the male part, that match threads of the female part or that match threads of the male part and that match threads of the female part.
6. The submersible pump of claim 5 wherein the threads of the gland ring comprise threads along an outer diameter of the gland ring and threads along an inner diameter of the gland ring.
7. The submersible pump of claim 6 wherein the threads along the outer diameter of the gland ring match threads along the inner diameter of the female part and wherein the threads along the inner diameter of the gland ring match threads along the outer diameter of the male part.
8. The submersible pump of claim 1 wherein the male part that comprises threads along the outer diameter, wherein the female part comprises threads along the inner diameter, and wherein the threads of the male part and the threads of the female part comprise matching threads.
9. The submersible pump of claim 8 wherein the elastomeric seal element is disposed axially on one side of the matching threads and wherein the non-elastomeric seal element is disposed axially on another side of the matching threads.
10. The submersible pump of claim 1 wherein the elastomeric seal element comprises an elastomeric material and a non-elastomeric anti-extrusion component.
11. The submersible pump of claim 1 wherein the non-elastomeric seal element comprises a C-ring, an E-ring or a spring-loaded polymeric lip seal element.
12. The submersible pump of claim 11 comprising a gland ring disposed axially to an open side of the C-ring, the E-ring or the spring-loaded polymeric lip seal element.
13. The submersible pump of claim 2 comprising a snap ring that axially locates the gland ring with respect to the male part, with respect to the female part or with respect to the male part and with respect to the female part.
14. The submersible pump of claim 1 wherein the elastomeric seal element disposed between the male part and the female part comprises metal or alloy that supports elastomeric material.
15. The submersible pump of claim 14 wherein the metal or alloy comprises a toroidal-wound spring shape.
16. The submersible pump of claim 1 wherein the male part comprises an annular groove dimensioned for receipt of the elastomeric seal element.
17. The submersible pump of claim 1 wherein the elastomeric seal element comprises a non-extrudable elastomeric seal element rated to a pressure differential of at least 10,000 psi.
18. The submersible pump of claim 1 wherein the non-elastomeric seal element comprises a core and a coating disposed on the core.
19. The submersible pump of claim 1 comprising a port and a passage extending from the port.
20. The submersible pump of claim 19 wherein the passage comprises an opening disposed axially between the elastomeric seal element and the non-elastomeric seal element.
Type: Application
Filed: Jan 27, 2014
Publication Date: Jul 31, 2014
Applicant: Schlumberger Technology Corporation (Sugar Land, TX)
Inventors: Arthur I. Watson (Sugar Land, TX), Boyle Suwono (Singapore), Bernard Kee Buck Tong (Johor), Christopher E. Featherby (Bartlesville, OK)
Application Number: 14/164,263
International Classification: F04D 29/08 (20060101);
