WO2016118140A1

WO2016118140A1 - Mechanical face seal with adaptable seat for electric submersible pump components

Info

Publication number: WO2016118140A1
Application number: PCT/US2015/012416
Authority: WO
Inventors: Jose CARIDAD URENA
Original assignee: Schlumberger Canada Limited; Services Petroliers Schlumberger; Schlumberger Technology B.V.; Schlumberger Technology Corporation
Priority date: 2015-01-22
Filing date: 2015-01-22
Publication date: 2016-07-28

Abstract

A mechanical face seal with an adaptable seat for electric submersible pump (ESP) components is provided. In an implementation, an end face mechanical seal system for a downhole shaft has a rotating seal face and an adaptable nonrotating seat to create a secure sealing interface during shaft misalignment. A nonrotating bellows self-adjusts the plane of the sealing interface to correct for a misaligned shaft, evenly biasing the seal faces in a uniform plane of rotation during shaft misalignment. The nonrotating bellows arrangement prevents the seal from having to conform to an out-of-plane seat every revolution. The secured sealing interface prevents leakage and introduction of abrasives from well fluid. The face seal may include a flexible mount to enable a biasing element to realign with the shaft. An inducer can be used to propel particulates away from the sealing interface and nonrotating parts.

Description

MECHANICAL FACE SEAL WITH ADAPTABLE SEAT FOR ELECTRIC SUBMERSIBLE PUMP COMPONENTS

BACKGROUND

[0001 ] End face mechanical seals for shafts play an important part in electric submersible pumps (ESPs). An end face mechanical seal is also referred to as a mechanical face seal or just a mechanical seal. Face seals are meant to preventing failure of the ESP by deterring well fluid outside the ESP from entering into a downhole motor or protector section of the ESP.

[0002] In conventional configurations for mechanical face seals for a shaft, the sealing interface that prevents fluids from passing is composed of the flat face of a moving ring sliding in relation to the flat face of a stationary mating ring, or seat, situated near where the shaft exits a casing or housing.

[0003] In the case of shaft misalignment, the rotating ring, driven by a rotating bellows attached to the shaft, is misaligned with respect to the stationary mating ring, or seat, and has to adjust to the plane of the stationary mating ring once per shaft revolution to compensate for the degree of deviance of the misaligned shaft. This constant compensating with each revolution of the shaft compromises the sealing integrity, because the response of the bellows to the constantly changing plane of the mating ring is not ideal. This conventional configuration of a mechanical face seal is apt to allow fluid leakage and the introduction of abrasives between the seal faces when the shaft is misaligned. SUMMARY

[0004] A mechanical face seal with an adaptable seat for electric submersible pump (ESP) components is provided. In an implementation, an apparatus comprises a housing encasing at least part of a shaft capable of rotation, a mechanical face seal mounted along the shaft, a rotating seal ring of the mechanical face seal driven by the shaft, a nonrotating seal ring of the mechanical face seal making a sealing interface with the rotating seal ring, a nonrotating biasing assembly between the nonrotating seal ring and the housing to hold a face of the nonrotating seal ring in a plane parallel to a face of the rotating seal ring when the shaft is misaligned with respect to the housing, a first end of the nonrotating biasing assembly attached to the nonrotating seal ring, and a second end of the nonrotating biasing assembly attached to the housing. In an implementation, an apparatus comprises an electric submersible pump (ESP) component including a housing encasing at least part of a shaft capable of rotation, a mechanical face seal mounted along the shaft, a rotating seal ring of the mechanical face seal driven by the shaft, a nonrotating seal ring to create a sealing interface with the rotating seal ring, a nonrotating bellows of the mechanical face seal having a first end and a second end, the first end of the nonrotating bellows fixed to the nonrotating seal ring to self-adjust a face of the nonrotating seal ring to a plane of rotation of the rotating seal ring during a misalignment of the shaft, and the second end of the nonrotating bellows held nonrotatable by the housing. An end face mechanical seal system for a downhole shaft comprises a rotating seal face and a nonrotating seal face creating a sealing interface, and a nonrotating bellows for evenly biasing the nonrotating seal face to the rotating seal face during a misalignment of the downhole shaft.

[0005] 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.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Certain embodiments of the disclosure will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various technologies described herein.

[0007] Fig. 1 is a diagram of an example mechanical face seal for electric submersible pump (ESP) components with a nonrotating biasing assembly.

[0008] Fig. 2 is a diagram of an example mechanical face seal with a nonrotating biasing assembly self-adapting to a misaligned shaft.

[0009] Fig. 3 is a diagram of an example mechanical face seal with a nonrotating biasing assembly, including a flexible mount.

[0010] Fig. 4 is a diagram of an example configuration of a flexible mount for a mechanical face seal with a nonrotating biasing assembly. [001 1 ] Fig. 5 is a diagram of an example flexible mount providing lateral adjustment and axial realignment of a face seal to a misaligned shaft.

[0012] Fig. 6 is a diagram of a flexible mount providing pivoting and axial realignment of a face seal to a misaligned shaft.

[0013] Fig. 7 is a diagram of an adjustable base platform for an example mechanical face seal with a nonrotating biasing assembly.

[0014] Fig. 8 is a diagram of an example bellows including a pivotable part and a springlike part.

[0015] Fig. 9 is a diagram of an example mechanical face seal with a nonrotating biasing assembly and a biasing element of one or more springs.

[0016] Fig. 10 is a diagram of an example inducer mechanism to prevent particulates in a well fluid from settling in a sealing interface or a bellows.

[0017] Fig. 11 is a flow diagram of an example method of sealing a misaligned shaft.

DETAILED DESCRIPTION

Overview

[0018] In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.

[0019] This disclosure describes a mechanical face seal with an adaptable seat for electric submersible pumps (ESPs). An example mechanical face seal for ESP components in high temperature, corrosive, and sandy well environments, for example, improves tolerance to shaft misalignment over conventional face seals. The example mechanical face seal is adaptable to minor shaft misalignment, improving the ability of its sealing interface to withstand abrasive particles present in the well fluid being pumped. "Misalignment" as used herein means that the shaft is intentionally or unintentionally out of alignment with an ideal shaft alignment for a given hardware. The shaft misalignment may be a lateral or angular deviation of the axis of the shaft caused by stress along an ESP string, caused by a non-ideal connection between ESP components that gets propagated along the ESP string, or may be caused by variation in manufacturing tolerances of the hardware parts. The misalignment does not have to be great to have deleterious effects. Only a few thousandths of an inch deviancy can eventually cause wear and leakage over time at bearings and face seals, and allow abrasives in the well fluid to enter between the surfaces of the sealing faces.

[0020] End face mechanical seals for shafts in ESPs are meant to prevent well fluid from entering a downhole motor, motor protector, or other component of the ESP. In conventional configurations for mechanical face seals for a downhole shaft, the sealing interface that prevents fluids from passing across the seal is composed of a flat face on a rotating ring that slides against, or rides on a film between, the flat face of a stationary mating ring, or seat, fixed to the stationary housing. The face on the nonrotating ring that conventionally functions as a seal seat can be composed of hard materials and combinations thereof, such as silicon carbide, ceramic, tungsten carbide, or graphitized silicon carbide embedded in the pump casing or housing. A softer material, such as carbon, may constitute the face of the rotating seal ring, or the face of the rotating ring may be one of the harder materials listed above. These two rings and their respective faces are machined in a lapping process to obtain a high degree of flatness, for a good seal. A biasing agent such as a spring or expanding bellows is used to drive the two faces together, creating the tightness of the seal.

[0021 ] The sliding interface between the two faces in a mechanical face seal prevents fluids from passing across the mechanical seal in appreciable quantities. In most conventional configurations, a bellows or one or more springs rotates with the shaft and backs the rotating seal ring, driving the rotating seal ring in unison with the shaft. The spring or bellows also applies pressure referred to as an actuation force that pushes the rotating seal ring against the stationary mating ring, or seat, held fixed by the case or housing to create a tight seal. The rotating ring is conventionally the one that adapts to a statically positioned seal ring affixed to the housing, but has to adapt every revolution of the shaft.

[0022] An example mechanical face seal with adaptable seat, as described herein, places the bellows or other biasing member on the stationary side of the seal instead of rotating with the shaft. This enables the seal to adapt to the new face plane of a rotating ring attached perpendicularly to a misaligned shaft only once, instead of once-per-revolution. Even though the shaft misalignment may only be a few thousands of an inch (but can be more), this degree of misalignment is enough to weaken a conventional sealing interface, especially over time and in the presence of abrasives in a well fluid. It is very expensive to retrieve and replace a downhole ESP component, especially in a subsea well. The example mechanical face seals described below provide robust and high availability ESP components. Other measures for enabling the example mechanical face seal to adapt to a misaligned shaft are also described below.

Example Mechanical Face Seals

[0023] Fig. 1 shows an example mechanical face seal 100 with a biasing assembly 102 fixed to a stationary (nonrotating) part of the housing 104 or other hardware at hand. The nonrotating biasing assembly 102 includes a biasing element, such as a bellows 106, encased springs, or other compressible-expandable member to provide an actuation force across the sealing interface 108. The actuation force pushes the face of the nonrotating ring 112 into the face of the rotating ring 110 to create the seal. The rotating ring 110 and the nonrotating ring 112 may be made of ceramic.

[0024] In Fig. 1 , components to the left of the sealing interface 108 rotate with the shaft 114, while components to the right of the sealing interface 108 do not rotate with the shaft 114, except for the shaft 114 itself. The rotating ring 110 may be secured by a rotating holder 116. Likewise, the nonrotating ring 112 may be secured by a nonrotating holder 118.

[0025] The secondary seals, such as o-rings, are static and not dynamic, which means that they remain stationary with respect to the moving or stationary parts that they touch. O-rings 120 may be present between the rotating ring 110 and rotating holder 116, and between the nonrotating ring 112 and the nonrotating holder 118, or, the rings may be press-fitted to their holders. The rotating holder 116 may be attached to the shaft 114 by one or more radial screws or by various other attachment devices. Between the rotating holder 116 and the shaft 114 there may be an o-ring 122 for sealing. A base ring 124 can be attached nonrotatably to the bellows 106 or other biasing element and to the housing 104. Depending on implementation, the biasing element may include a bellows 106, one or more springs, one or more magnets, a compressed material, and so forth. There may be an o-ring 126 to form a seal between the base ring 124 and the housing 104 or other static hardware. An antirotation mechanism 128 may be attached between the base ring 124 and the housing 104.

[0026] The example mechanical face seal 100, including the nonrotating biasing assembly 102, improves tolerance to shaft misalignment over conventional face seals and improves the ability of the example mechanical face seal 100 to withstand abrasive particles that are present in the well fluid being pumped.

[0027] Fig. 2 shows an example mechanical face seal 100 during a shaft misalignment (shaft not shown). The misalignment is shown diagrammatically, as exaggerated and not to scale, for descriptive purposes. The nonrotating biasing assembly 102 holds the face of the nonrotating seal ring 112 in a plane parallel to a face of the rotating seal ring 110 when the shaft 114 is misaligned with respect to the housing 104. By comparison, in conventional face seals, a rotating bellows attached to the shaft 114 needs to constantly adjust the rotating ring to the permanently off-plane face of the stationary seat, once per shaft revolution.

[0028] In Fig. 2, an implementation of the bellows 106 or other biasing element remains coaxial with an ideal shaft orientation, not the misaligned shaft orientation, but the nonrotating ring 112 has adapted its plane of rotation to the rotating ring 110, which is perpendicular to the misaligned shaft 114. In this scenario, axis 204 of the rotating ring 110 may be offset from the axis 206 of the nonrotating ring 112, causing a mismatch of the sealing faces. This mismatch of the sealing faces can be negligible, and happens when the misalignment has resulted from the shaft 114 pivoting to a slight degree at some point a distance away from the sealing interface 108 of the mechanical face seal 100. This offset of axes 204 & 206 that results in the mismatch of the faces at the sealing interface 108 may be insignificant for a given application depending on the width of each face on the seal rings 110 & 112 and the degree of shaft deflection. On the other hand, the slight mismatch of the faces of the seal rings 110 & 112 may benefit from correction.

[0029] During adaptation to a misaligned shaft 114, the bellows 106 or other biasing element may have one side 200 that is more extended or decompressed than an opposite side 202, which pushes with more activation force because it is compressed more than the other side 200. Because shaft misalignment is usually small, this biasing difference between sides of the bellows 106 may be correspondingly small. However, over time, the imbalance in the application of the actuation force across the surface of the face of the nonrotating ring 112 may result in some compromised sealing integrity, especially for bellows 106 that are relatively stiff, as one side (202) of the sealing interface 108 may be tighter than the other side (200).

[0030] To relieve an imbalance of compression in the bellows 106, Fig. 3 shows an example mechanical face seal 100 for ESPs that includes a flexible mount 300 or deformable mount for further adapting the sealing interface 108 to the orientation of the shaft 114 during shaft misalignment. The flexible mount 300 can dynamically self-adjust to changes in a deviancy of the shaft 114 with respect to the housing 104, or in an embodiment, can be permanently set in a position.

[0031 ] In an implementation, the flexible mount 300 attaches an end of the nonrotating biasing assembly 102, such as the base ring 124, to the housing 104 to enable the nonrotating biasing assembly 102 to better align at least in part with the misaligned shaft 114. The flexible mount 300 provides adaptive cushioning or deformation, and may be made of a slightly deformable, elastic, springy, or resilient material. In an implementation, the flexible mount 300 is a layer or ring of a rubber, such as a perfluoroelastomer, which has suitable compression set properties and excellent chemical resistance, heat resistance, oil resistance, gas permeability resistance, physical strength, and water resistance properties. The flexible mount 300 may be, for example, an elastic layer, a rubber collar, a compressible washer, a cushion mount, a self- adjusting platform mount, a jointed mount, a gimbaled mount, a spring or spring-loaded mount, or the like. The flexible mount 300 may also be made of a relatively stiff material that obtains a degree of flexibility or deflection from its geometry, such as a stainless steel in leaf spring form. The flexible mount 300 allows the bellows 106 or nonrotating biasing assembly 102 to align with a misaligned shaft 114.

[0032] Fig. 4 shows an example flexible mount 300 attached to the housing 104. The flexible mount 300 provides some "give" when the biasing assembly 102 adapts to the misaligned shaft 114. In other words, the flexible mount allows the biasing assembly 102 to reorient slightly to a deviated shaft orientation, including allowing the biasing assembly 102 to pivot, rotate around a radial axis, or realign to become more coaxial with the misaligned shaft 114. Even though the adaptation may only be in thousandths of an inch, the benefit to longevity of the face seal 100 and the integrity of the sealing interface 108 can be significant, given the cost of retrieving an ESP component.

[0033] Fig. 5 shows an example mechanical face seal 100 in which a flexible mount 300 has provided relief of some of the unequal compression of a bellows 106 during adaptation to a misaligned shaft 114. The flexible mount 300 may be of a material selected to have a lower modulus of elasticity than the stiffness of the structure of the bellows 106, so that an unequal compression of the bellows can self-relieve by compression 502 or deformation the flexible mount 300. Or, instead of relying on the deformability of the material, the structural geometry of the flexible mount 300 may provide less stiffness than the compressive stiffness of the bellows 106, allowing the bellows 106 to relieve unequal compression.

[0034] In an implementation, the flexible mount 300 may also allow lateral movement 504 of a base of the nonrotating biasing assembly 102, enabling the nonrotating biasing assembly 102, or at least a bellows 106 that is stiff to all but axial motion, to align more coaxially with the misaligned shaft 114.

[0035] Fig. 6 shows an example mechanical face seal 100 in which the stiffness of the flexible mount 300 is selected to deform to allow the bellows 106 or biasing assembly 102 to pivot slightly around a radial axis when the face of the rotating ring 110 meets the face of the nonrotating ring 112 in a plane perpendicular to the misaligned shaft 114. The enables the bellows 106 or biasing assembly to better align coaxially with the misaligned shaft 114, which in turn enables the biasing element, such as the bellows 106, to apply the actuation force to the sealing interface 108 more evenly across the surface area of the faces 110 & 112, since the biasing element is more in line to do so.

[0036] Fig. 7 shows an example mechanical face seal 100 with a pivotable base 700. The pivotable base 700 provides an adjustable or self-adjusting platform for seating the nonrotating biasing assembly 102 during construction of an ESP component. Support 702 for the platform may be adjustable or self-adjusting. For example, the support 702 may be set-screws on a cartridge version of the mechanical face seal 100. Or the support may a thermoset polymer 704 that is activated or injected into a support cavity of the mechanical face seal 100 once the mechanical face seal 100 is in place in an ESP that has shaft deviation present. The supports 702 can be user- adjustable or user-settable when sensing equipment is in place during manufacture to quantify the amount of shaft misalignment and verify the degree of correction to apply to the support 702.

[0037] Fig. 8 shows an example biasing element in the form of an example bellows 106. A first part 802 of the bellows 106 near the base ring 124 that attaches to the housing 104 of an ESP has a higher support stiffness than a second part 804 of the bellows 106 near the holder 118 of the nonrotating face seal 112. The first part 802 of the bellows 106 can bend or be bent to correct at least in part to an angle of shaft misalignment and is stiff enough to hold the angle of bend while the second part 804 of the bellows 106 with different springiness applies the actuation force along a normal to the rotation plane of the rotating seal ring 110. The first part 802 and the second part 804 of the bellows 106 may be different thicknesses of the same material (e.g., metal), or may be different materials altogether with different stiffness and holding properties. Thus, the example bellows 106 provides adaptation to a deviated shaft, while still applying actuation force to a sealing interface 108 along a vector that is coaxial with the shaft misalignment. In an implementation, the first part 802 and the second part 804 are different gauges of INCONEL 718, for example (Specialty Metal Corporation, New Hartford, NY).

[0038] Fig. 9 shows an example mechanical face seal 900 in which the biasing element of the nonrotating biasing assembly 102 is one or more springs 902 instead of a bellows 106. If the shaft 114 is deviated from ideal axial orientation, then the face of the rotating ring 110 remains perpendicular to the axis of the shaft 114, but misaligned with respect to the housing 104 of the ESP component. The one or more springs 902 enable the nonrotating biasing assembly 102 to adjust the plane of the face of the nonrotating ring 112 to a plane that is parallel to the face of the rotating ring 110. The biasing element may also be a compressible material, or magnets, for example, to apply an actuation force to the sealing interface 108.

[0039] Fig. 10 shows an example mechanical face seal 100 with an inducer mechanism 1002 to propel or circulate particulates in a well fluid away from settling and collecting at the sealing interface 108 and the nonrotating biasing assembly 102. The inducer mechanism 1002 (not shown to scale) may consist of fins, projections, tabs, or impeller geometry that rotate with the rotating elements of the mechanical face seal 100. The size of the inducer parts depends on the speed of rotation and can depend on the types of well fluid in play. The inducer mechanism 1002 may also include a rough surface or small projections on the perimeter of the rotating ring 110 adjacent to the sealing interface 108 that helps the sealing interface 108 self-clean. The inducer mechanism 1002 at least keeps the well fluid moving and prevents formation of slow moving laminar layers of the well fluid near the sealing interface 108. This fluid action keeps abrasive particulates away from the sealing interface 108, and ultimately from entering between the faces of the rotating ring 110 and the nonrotating ring 112. The inducer mechanism 1002 can also keep the well fluid moving across the sides of the nonrotating biasing assembly 102, especially when a bellows 106 is used as the biasing element of the mechanical face seal 100. Because the nonrotating biasing assembly 102 does not rotate, sand and other particles in the well fluid have a tendency to settle in the corrugations or pleats of the bellows 106, eventually clogging and impeding spring action of the bellows 106. A sheath or shroud 1004 may also be used over the bellows 106 to keep particulates out of the corrugations.

[0040] The configuration of the example mechanical face seal 100 as described reduces vibration, movement, and disturbance of the sealing interface 108 as the rotating ring 110 and the nonrotating ring 112 rotate with respect to each other, since they remain in parallel planes during operation. The tendency of the sealing interface 108 to open a gap during operation is reduced compared to conventional face seals, reducing in turn the possibility of leakage through the example face seal 100 and decreasing the presence of abrasives from the well fluid intervening between the rotating ring 110 and the non rotating ring 112.

[0041 ] The example face seal 100 is useful for ESPs that pump fluids with a high solids content, because the example face seal 100 excludes solid particulates when minor shaft misalignment is present. The example face seal 100 is also useful in ESPs with metal bellows-type seals, such as those used for steam assisted gravity drainage (SAGD) and steam flooding, that are less tolerant to misalignment as compared to seals with elastomer bellows, as used in conventional ESPs.

Example Method

[0042] Fig. 11 shows an example method 1100 of sealing a misaligned shaft in an electric submersible pump (ESP) component. In the flow diagram, operations are shown in individual blocks.

[0043] At block 1102, a face seal is placed to seal a shaft of an ESP component.

[0044] At block 1104, a nonrotating biasing assembly with flexible mount is placed in the face seal to adapt a sealing interface of the face seal to a misalignment of the shaft. Conclusion

[0045] 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.

Claims

1 . An apparatus, comprising:

a housing encasing at least part of a shaft capable of rotation;

a mechanical face seal mounted along the shaft;

a rotating seal ring of the mechanical face seal driven by the shaft; a nonrotating seal ring of the mechanical face seal making a sealing interface with the rotating seal ring;

a nonrotating biasing assembly adaptively mounted between the nonrotating seal ring and the housing to hold a face of the nonrotating seal ring in a plane parallel to a face of the rotating seal ring when the shaft is misaligned with respect to the housing;

a first end of the nonrotating biasing assembly attached to the nonrotating seal ring; and

a second end of the nonrotating biasing assembly attached to the housing.

2. The apparatus of claim 1 , wherein a biasing element of the nonrotating biasing assembly comprises one of a bellows, a spring, a magnet, or a compressed material.

3. The apparatus of claim 1 , further comprising a flexible mount attaching the second end of the nonrotating biasing assembly to the housing to enable the nonrotating biasing assembly to align at least in part with the misaligned shaft.

4. The apparatus of claim 3, wherein the flexible mount comprises one of an elastic layer, a rubber collar, a compressible washer, an adjustable platform mount, a jointed mount, or a gimbaled mount.

5. The apparatus of claim 3, wherein the flexible mount allows a pivoting movement and a sliding lateral movement of the second end of the nonrotating biasing assembly with respect to the housing to coaxially align at least part of the nonrotating biasing assembly with the misaligned shaft for applying an actuation force evenly from the nonrotating biasing assembly to the sealing interface.

6. The apparatus of claim 3, wherein the flexible mount dynamically self-adjust to changes in a deviancy of the shaft with respect to the housing.

7. The apparatus of claim 3, wherein a component of a bellows comprises the flexible mount.

8. The apparatus of claim 7, wherein the bellows coaxially aligns the nonrotating seal ring with the shaft when the shaft is misaligned with respect to the housing.

9. The apparatus of claim 7, wherein a first part of the bellows proximate to the housing comprises the flexible mount and a second part of the bellows proximate to the nonrotating seal ring comprises a biasing element of the nonrotating biasing assembly.

10. The apparatus of claim 9, wherein the biasing element of the nonrotating biasing assembly comprises one of a formed metal, a polymer, an elastomer, or a magnetic material.

11 . The apparatus of claim 9, further comprising a sheath over the biasing element to prevent particulates from impeding an action of the bellows.

12. The apparatus of claim 1 , further comprising an inducer attached to the mechanical face seal to propel particulates away from the sealing interface.

13. The apparatus of claim 12, wherein the inducer propels particulates away from both the sealing interface and the nonrotating biasing assembly.

14. An apparatus, comprising:

an electric submersible pump (ESP) component including a housing encasing at least part of a shaft capable of rotation;

a mechanical face seal mounted along the shaft;

a rotating seal ring of the mechanical face seal driven by the shaft; a nonrotating seal ring to create a sealing interface with the rotating seal ring;

a nonrotating biasing element of the mechanical face seal having a first end and a second end;

the first end of the nonrotating biasing element fixed to the nonrotating seal ring to self-adjust a face of the nonrotating seal ring to a plane of rotation of the rotating seal ring during a misalignment of the shaft;

and

the second end of the nonrotating biasing element held nonrotatable by the housing.

15. The apparatus of claim 14, further comprising at least one inducer attached to the mechanical face seal to propel particulates in a well fluid away from the nonrotating biasing element and the sealing interface.

16. The apparatus of claim 14, further comprising a flexible mount between the second end of the nonrotating biasing element and the housing to align the nonrotating biasing element with the misaligned shaft for evenly applying an actuation force to the sealing interface.

17. The apparatus of claim 16, wherein the nonrotating biasing element and the flexible mount adapt a face plane of the nonrotating seal ring to a face plane of the rotating seal ring perpendicular to the shaft when the shaft is misaligned with respect to the housing.

18. The apparatus of claim 14, wherein the nonrotating biasing element comprises one of a bellows, a spring, a magnet, or a compressed material .

19. An end face mechanical seal system for a downhole shaft, comprising:

a rotating seal face and a nonrotating seal face creating a sealing interface; a nonrotating bellows for evenly biasing the nonrotating seal face to the rotating seal face during a misalignment of the downhole shaft; and

an inducer to self-clean the sealing interface and the nonrotating bellows.

20. The end face mechanical seal system of claim 19, further comprising an adaptable mount element to adapt an axial alignment of the nonrotating bellows to an axial alignment of the downhole shaft during the misalignment of the downhole shaft.