Seal assemblies for use within a wellbore

Abstract

A seal including a seal body, an inner arm protruding from the seal body and configured to engage an inner surface, and an outer arm protruding from the seal body and configured to engage an outer surface. The inner arm includes an inner seal protrusion proximate to a distal end of the inner arm and an inner support protrusion. The outer arm includes an outer seal protrusion proximate to a distal end of the outer arm and an outer support protrusion. The inner seal protrusion and the outer seal protrusion define a seal width, and the inner support protrusion and the outer support protrusion define a support width less than the seal width while the seal is in an uncompressed state.

Description

SEAL ASSEMBLIES FOR USE WITHIN A WELLBORECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 18 / 662,229 entitled “METAL SEAL FOR DYNAMIC DOWNHOLE ENVIRONMENTS,” filed May 13, 2024, U.S. Provisional Application No. 63 / 664,451, entitled “AXIAL SPRING CHEVRON SEAL,” filed June 26, 2024, and U.S. Provisional Application No. 63 / 664,906, entitled “FLOW CONTROL VALVE WITH A RETRACTABLE CAP SEAL AND METHODS FOR USE THEREOF,” filed June 27, 2024, each of which is hereby incorporated by reference in its entirety for all purposes.BACKGROUND

[0002] The present disclosure is directed to seal assemblies for use within a wellbore.

[0003] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and / or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

[0004] Seals (e.g., O-rings, gaskets, packing, etc.) may fluidly isolate one space from another. Often, seals are formed of a polymer, which provides fluid-blocking and / or cushioning features. Seals prevent fluid leaks, provided that adequate sealing engagement with associated components is maintained. Fluid flowing through unplanned paths (e.g., leaks) can erode components and result in inefficiencies in the mechanisms. There is a need in the art for improvements in sealing leak paths in flow control.SUMMARY

[0005] A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary ofthese certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.

[0006] Various refinements of the features noted above may exist in relation to various aspects of the present disclosure. Further features may also be incorporated in these various aspects as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to one or more of the illustrated embodiments may be incorporated into any of the above-described aspects of the present disclosure alone or in any combination. The brief summary presented above is intended only to familiarize the reader with certain aspects and contexts of embodiments of the present disclosure without limitation to the claimed subject matter.

[0007] In certain embodiments, a seal includes a seal body, an inner arm protruding from the seal body and configured to engage an inner surface, and an outer arm protruding from the seal body and configured to engage an outer surface. The inner arm includes an inner seal protrusion proximate to a distal end of the inner arm and an inner support protrusion. The outer arm includes an outer seal protrusion proximate to a distal end of the outer arm and an outer support protrusion. The inner seal protrusion and the outer seal protrusion define a seal width, and the inner support protrusion and the outer support protrusion define a support width less than the seal width while the seal is in an uncompressed state.

[0008] In certain embodiments, a seal assembly includes a chevron stack of polymeric rings disposed radially between and axially slidably engaged with an inner tube section and an outer tube section, a first spring disposed radially between the inner tube section and the outer tube section, and a second spring disposed radially between the inner tube section and the outer tube section. The chevron stack of polymeric rings includes a first chevron ring, a second chevron ring, and a dual-nosed ring disposed axially between the first chevron ring and the second chevron ring. The chevron stack of polymeric rings is axially disposed between the first spring and the second spring. The first spring and the second spring axially compress the chevron stack of polymeric rings.

[0009] In certain embodiments, a flow control valve includes a choke sleeve, a spacer including a recess, a choke seal, a piston slidable relative to the choke sleeve and the spacer between a first position and a second position, and a seal assembly. A first end of the spacer is engaged with an end of the choke sleeve. An end of the choke seal is engaged with a second end of the spacer. The piston includes a groove and a seal surface. The seal assembly includes a first seal portion disposed in the groove and a cap seal having a first side and a second side. While the piston is in the first position, the first side of the cap seal is engaged with the choke sleeve and the second side of the cap seal is engaged with the first seal portion. While the piston is in the second position, the first side of the cap seal is engaged with the recess, the second side of the cap seal is engaged with the seal surface of the piston, and the choke seal is disposed between the cap seal and the first seal portion.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which:

[0011] FIG. 1 is a cross-sectional view of a well system including a sliding sleeve assembly and a flow control valve, in accordance with aspects of the present disclosure;

[0012] FIG. 2 is a perspective view of an annular metal seal, in accordance with aspects of the present disclosure;

[0013] FIG. 3 is a radial cross-sectional view of a portion of the annular metal seal contacting an inner surface, in accordance with aspects of the present disclosure;

[0014] FIG. 4 is a radial cross-sectional view of the portion of the annular metal seal of FIG. 3 dynamically contacting an outer surface, in accordance with aspects of the present disclosure;

[0015] FIG. 5 is a perspective view of an annular metal seal with non-circumferential support protrusions, in accordance with aspects of the present disclosure;

[0016] FIG. 6 is a radial cross-sectional view of a portion of an annular metal seal with a second support protrusion distal to a seal protrusion, in accordance with aspects of the present disclosure;

[0017] FIG. 7 is a flowchart of a method of sealing in a downhole environment, in accordance with aspects of the present disclosure;

[0018] FIG. 8 is a partial side cross-sectional view of a first embodiment of an axial seal assembly of a sliding sleeve assembly, in accordance with aspects of the present disclosure;

[0019] FIG. 9 is a partial side cross-sectional view of a second embodiment of an axial seal assembly, in accordance with aspects of the present disclosure;

[0020] FIG. 10 is a partial side cross-sectional view of a third embodiment of an axial seal assembly, in accordance with aspects of the present disclosure;

[0021] FIG. 11 is a side cross-sectional view of a portion of a first embodiment of an axial seal assembly including the annular metal seal of FIG. 2, in accordance with aspects of the present disclosure;

[0022] FIG. 12 is a side cross-sectional view of a portion of a second embodiment of an axial seal assembly including the annular metal seal of FIG. 2, in accordance with aspects of the present disclosure;

[0023] FIG. 13 is a cross-sectional view of an embodiment of a flow control valve including a valve seal assembly, in accordance with aspects of the present disclosure;

[0024] FIG. 14A is a cross-sectional view of the valve seal assembly of FIG. 13, in which a piston of the flow control valve is in a first position, in accordance with aspects of the present disclosure;

[0025] FIG. 14B is a cross-sectional view of the valve seal assembly of FIG. 13, in which the piston of the flow control valve is in a second position as the piston moves toward a fully closed position, in accordance with aspects of the present disclosure;

[0026] FIG. 14C is a cross-sectional view of the valve seal assembly of FIG. 13, in which the piston of the flow control valve is in a third position, in accordance with aspects of the present disclosure;

[0027] FIG. 14D is a cross-sectional view of the valve seal assembly of FIG. 13, in which the piston of the flow control valve is in a fourth position as the piston moves toward the first position, in accordance with aspects of the present disclosure; and

[0028] FIG. 14E is a cross-sectional view of the valve seal assembly of FIG. 13, in which the piston of the flow control valve is in the first position, in accordance with aspects of the present disclosure.DETAILED DESCRIPTION

[0029] One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers’ specific goals, such as compliance with system- related and enterprise-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0030] When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0031] As used herein, the terms “connect,” “connection,” “connected,” “in connection with,” and “connecting” are used to mean “in direct connection with” or “in connection with via one or more elements”; and the term “set” is used to mean “one element” or “more than one element.”Further, the terms “couple,” “coupling,” “coupled,” “coupled together,” and “coupled with” are used to mean “directly coupled together” or “coupled together via one or more elements.”

[0032] In addition, as used herein, the terms “real-time” or “substantially real-time” may be used interchangeably and are intended to described operations (e.g., computing operations) that are performed without any human-perceivable interruption between operations. For example, data relating to the systems described herein may be collected, transmitted, and / or used in control computations in “substantially real-time”, such that data readings, data transfers, and / or data processing steps may occur once every second, once every 0.1 seconds, once every 0.01 seconds, or even more frequently, during operations of the systems (e.g., while the systems are operating). In addition, as used herein, the terms “automatic” and “automated” are intended to describe operations that are performed are caused to be performed, for example, solely by an analysis system without human intervention.

[0033] The present disclosure relates to seal assemblies for use within a well system. Seals are used to fluidly isolate areas of the well system. However, traditional seals may lose sealing engagement with the components based on temperature and age. As such, seal assemblies may include redundant features to ensure a proper seal is maintained.

[0034] In some embodiments, the seal assemblies may include an annular metal seal for use in a downhole environment configured to seal an inner surface from an outer surface. The annular metal seal may include a body, an outer arm disposed on one side of the body, and an inner arm disposed on the other side of the body. Additionally, the annular metal seal may include one or more protrusions extending from the arms. The protrusions may contact the surfaces to create a fluid-tight seal. For example, the protrusions of the annular metal seal may apply an expansion force to create the fluid- tight seal via an elastic restoring force of the annular metal seal and / or a fluid pressure between the inner arm and the outer arm of the annular metal seal. Additionally, the annular metal seal may include additional protrusion(s) configured to scrape a surface (e.g., the outer surface) during mating of the annular seal and the surface to provide a clean surface for creating the fluid-tight seal.

[0035] In some embodiments, the seal assemblies may include an axial seal assembly with slidable seal elements and one or more springs configured to seal an inner tube section and an outertube section. The springs may apply an axial force to produce axial compression of the slidable seal elements, sometimes referred to as “energization.” The slidable seal elements may radially deflect between the inner tube section and the outer tube section, thereby creating a tight, slidable seal in response to the energization. Such energization may increase the efficiency of the axial seal assembly for various temperatures and / or wear of the axial seal assembly.

[0036] In some embodiments, the seal assemblies may include a seal assembly configured to be used in a flow control valve. A flow control valve may control the flow of fluid (e.g., hydrocarbons, injection fluid) through the flow control valve (e.g., into the production tubing string). Undesirable fluid flow through components of the flow control valve (e.g., leak paths) may reduce the effectiveness of the flow control valve. As such, the flow control valve may include sealing assemblies to control, reduce, or eliminate fluid flow through potential leak paths of the flow control valve. For example, the flow control valve may have one or more seal assemblies disposed between a piston and a choke sleeve of the flow control valve.

[0037] FIG. 1 is a cross-sectional view of a well system 10 including a sliding sleeve assembly and a flow control valve. By way of example, a casing 12 may be disposed along a wellbore 14 drilled into a subterranean formation 16. The casing 12 may have an interior surface 18 and an exterior surface 20. The casing 12 may include a wellhead 22 and a tube assembly 24. The tube assembly 24 may include one or more tube sections 26 (e.g., 1, 2, 3, 4, 5, 6, etc.), depending on the depth and application of the wellbore 14. In some embodiments, the tube sections 26 may be substantially identical to one another. In some embodiments, the tube sections 26 may vary in length and / or other features (e.g., external brackets, internal baffles, external grips, etc.) along the tube sections 26. The tube assembly 24 may also include one or more sliding sleeve assemblies 28 connected to the tube sections 26. Each sliding sleeve assembly 28 may include multiple axial seal assemblies. Each sliding seal assembly may include sliding seal elements axially moveably and slidably engaged with an inner tube section and an outer tube section, as will be explained in greater detail below. For example, a sliding sleeve assembly 28 may include one or more annular metal seals and / or an axial seal assembly, as described herein. In some embodiments, the tube sections 26 and sliding sleeve assemblies 28, and thus the tube assembly 24, are substantially circular in cross-sectional shape.

[0038] The well system 10 may also include a tree 30 at the wellhead 22. In some embodiments, the tree 30 may include one or more flow control valves 32 each configured to control the flow of fluid (e.g., hydrocarbons) through the flow control valve 32. The flow control valves 32 may each include one or more seal assemblies disposed between a piston and a choke sleeve of the flow control valve 32, as described herein, to block leaks.

[0039] As described in further detail below, the seal assemblies may include an annular metal seal configured to fluidly seal a dynamic outer surface from an inner surface. To this end, the annular metal seal may include a body, an outer arm disposed on one side of the body, an inner arm disposed on the other side of the body, and one or more protrusions extending from the outer arm and the inner arm, respectively, configured to contact the outer surface and the inner surface, respectively. An elastic restoring force of the annular metal seal and / or a fluid pressure between the inner arm and the outer arm of the annular metal seal may create an expansion force that establishes the seal between the protrusions and the surfaces.

[0040] FIG. 2 is a perspective view of an annular metal seal 100. In some embodiments, the annular metal seal 100 includes a seal body 102 with an outer arm 104 and an inner arm 106 protruding axially therefrom. The annular metal seal 100 includes one or more seal protrusions 108 proximate to a distal end of the arms 104, 106 to create a seal between the arms 104, 106 of the annular seal 100 and the inner surface and outer surface against which the annular seal 100 creates the fluid seal. The seal protrusion 108 extends radially toward the adjacent surface to increase the pressure between the seal and the surface at that point, which may produce elastic and / or plastic deformation of the seal protrusion 108 and / or material of the surface to create the fluid- tight seal. In some embodiments, the seal protrusion 108 may be convex, such as parabolic, semi-elliptical, semi-circular, or another curved convex shape. In some embodiments, at least a portion of the seal protrusion 108 may be planar, such as a triangular, trapezoidal, or partially planar and partially curved. The seal protrusion 108 is circumferential around the annular seal 100.

[0041] In some embodiments, the annular metal seal 100 includes one or more support protrusions 110. The support protrusion 110 is located on an arm of the seal axially between the seal body 102 and the seal protrusion 108. FIG. 3 is a radial cross-sectional view of a portion ofthe annular metal seal 100 contacting an inner surface 112. In some embodiments, the support protrusion 110 supports the arm (e.g., inner arm 106 or outer arm 104 on which the support protrusion is located) against the adjacent surface (e.g., inner surface 112) while the annular metal seal 100 is in a compressed state (e.g., the annular metal seal 100 is installed). In some embodiments, the annular metal seal 100 may be exposed to high fluid pressures in the volume 114 between the inner arm 106 and the outer arm 104. The fluid pressure, in some examples, may apply a force to the arm(s) 104, 106 that can elastically or plastically deform the arm(s). Plastic deformation of the arm(s) 104, 106 may result in a lower seal pressure at the seal protrusion(s) 108. Deformation of the arm(s) 104, 106 may lead to fatigue failure of the metal of the arm(s) 104, 106, which may reduce the operational lifetime of the annular seal 100.

[0042] In some embodiments, the support protrusion 110 is substantially continuous around the full circumference of the annular seal 100 (such as in the embodiment illustrated in FIG. 2). For example, an inner support protrusion 110 may be circumferential around the annular seal 100 proximate to the inner surface 112 (e.g., the inner support protrusion extends radially inwardly). In addition, an outer support protrusion 110 may be circumferential around the annular seal 100 proximate to the outer surface (e.g., radially outer surface 116 of FIG. 4). In some embodiments, the support protrusions 110 (i.e., an inner support protrusion and an outer support protrusion) may define a support width 118 of the annular seal 100, and the seal protrusions 108 (i.e., an inner seal protrusion and an outer seal protrusion) define a seal width 120 of the annular seal 100. In some embodiments, the support width 118 may be less than the seal width 120 while the annular seal 100 is in an uncompressed state. For example, before the annular seal 100 is compressed between an inner surface 112 and an outer surface 116 and the annular seal 100 is in an elastically relaxed state, the support width 118 may be less than the seal width 120. In some embodiments, the support width 118 may be less than the seal width 120 while the annular seal 100 is in the compressed state. For example, when the annular seal 100 is in a compressed state with the inner seal protrusion 108 and outer seal protrusion 108 contacting the inner surface 112 and the outer surface 116, respectively, at least one of the inner support protrusion 110 or the outer support protrusion 110 may not contact the adjacent inner surface 112 or the outer surface 116.

[0043] The support width 118 and the seal width 120 may define a protrusion width ratio of the annular seal 100. In some embodiments, the protrusion width ratio may be in a range having anupper value, a lower value, or upper and lower values including any of 0.99, 0.98, 0.97, 0.95, 0.925, 0.90, 0.85, 0.80, or any values therebetween. In some examples, the protrusion width ratio may be less than 0.99. In some examples, the protrusion width ratio may be greater than 0.80. In some examples, the protrusion width ratio is between 0.80 and 0.99. In some examples, the protrusion width ratio may be between 0.85 and 0.98. In some examples, the protrusion width ratio may be between 0.925 and 0.97.

[0044] The protrusion width ratio in combination with a material of the arms and / or the seal body, in some embodiments, may enable the seal to maintain a sufficient seal force between the seal protrusion(s) and the surface(s) by positioning the seal protrusions radially externally (i.e., radially outwardly of the outer arm and radially inward of the inner arm) from the seal. In some embodiments, the seal force may be greater than a support force applied radially externally by the support protrusion(s) of the seal in the compressed state. In at least one example, before pressure is applied to the annular seal 100, the support protrusion(s) may not contact the surface(s) while the annular seal is in the compressed state, and the support force may be zero. In some embodiments, once pressure has been applied to the annular seal 100, the seal force may be equal to a support force applied radially externally by the support protrusion(s) of the annular seal in the compressed state. In at least one embodiment, once pressure has been applied to the annular seal 100, the seal force may be less than a support force applied radially externally by the support protrusion(s) of the annular seal in the compressed state. For example, an annular seal with multiple non-circumferential support protrusions may apply a support force greater than the seal force applied by the seal protrusion(s) while maintaining a sufficient seal force.

[0045] In some embodiments, the annular seal may apply a seal pressure that is based at least partially on the seal force and a geometry and / or material of the seal protrusion. For example, an apexed contact point of the seal protrusion (e.g., curved or pointed) between the seal protrusion and the surface with which the seal protrusion makes contact may concentrate the seal force in a smaller surface area than a planar contact point which may distribute the seal force. In some embodiments, the seal pressure may elastically and / or plastically deform a portion of the seal protrusion and / or the surface that the seal protrusion contacts such that the seal protrusion and surface mate and form a fluid seal. In some embodiments, the seal protrusion may include a coating having a lower hardness than the seal protrusion and / or the arm of the seal to enable greaterdeformation of the seal protrusion at the contact point. In some embodiments, the coating may be a metal, polymer, or other suitable coating.

[0046] In some embodiments, the annular seal may apply a support pressure that is based at least partially on the support force and a geometry and / or material of the support protrusion. For example, an apexed contact point of the support protrusion (e.g., curved or pointed) between the support protrusion and the surface with which the support protrusion makes contact may concentrate the support force in a smaller surface area than a planar contact point which may distribute the support force. In some embodiments, the support protrusion may have a planar contact surface to distribute the support force and lower the support pressure. In some embodiments, the support protrusion may have an apexed edge in an axial direction that concentrates the support force and produces a scraping edge that cleans debris from the surface (e.g., a dynamic inner surface and / or dynamic outer surface) prior to the seal protrusion contacting (and sealing with) the surface. In some embodiments, a planar contact point may scrape the surface with which the support protrusion makes contact. In some embodiments, the support pressure may elastically and / or plastically deform a portion of the support protrusion and / or surface that the support protrusion contacts such that the support protrusion and surface engage and form a scraping edge. In some embodiments, the support protrusion may include a coating having a lower hardness than the support protrusion and / or the respective arm to enable greater deformation of the support protrusion at the contact point. In some embodiments, the coating may be a metal, polymer, or other suitable coating.

[0047] FIG. 4 is a radial cross-sectional view of the portion of the annular metal seal 100 of FIG. 3 dynamically contacting an outer surface 116. In some embodiments, the support protrusions 110 may further axially center the dynamic surface 116 (e.g., the outer surface 116 of FIG. 4) on the annular seal 100. For example, a support protrusion 110 may have a tapered leading edge 122 (e.g., oriented away from the respective seal protrusion in an axial direction) that contacts a portion of the dynamic surface and urges the dynamic surface 116 in a radial direction. In some embodiments, the support protrusions 110 may substantially center the inner surface 112 and the outer surface 116 relative to one another whether the support protrusions 110 are circumferentially continuous or not.

[0048] FIG. 5 is a perspective view of an embodiment of an annular seal 200 with non- circumferential (e.g., non-continuous) support protrusions 210 on an outer arm 204. In some embodiments, a support protrusion 210 is positioned around a portion of the circumference of the annular seal 200 that is less than the entire circumference. For example, multiple inner support protrusions 210 may be positioned around the circumference of the annular seal 200 proximate to the inner surface with gaps between the inner support protrusions. In addition, multiple outer support protrusions 210 may be positioned around the circumference of the annular seal 200 proximate to the outer surface with gaps between the outer support protrusions.

[0049] FIG. 6 is a radial cross-sectional view of a portion of another embodiment of an annular seal 300. In some embodiments, the annular seal 300 may include a seal material that is different from an arm material. For example, the seal protrusion(s) 308 may be formed by application of a seal material to a surface of the arm (e.g., inner arm or outer arm). In some embodiments, the seal material of an outer seal protrusion may be different from the seal material of an inner seal protrusion. In some examples, the seal material may be harder than the arm material to limit and / or reduce wear to the seal protrusion 308. In some examples, the seal material may be a lubricious material to provide a relatively low coefficient of friction during mating of the seal protrusion with the surface. In some examples, the seal material may be more compliant than the arm material to conform to the adjacent surface and form the fluid seal.

[0050] In some embodiments, the annular seal 300 may include an arm material that is different from a body material. For example, the arm material may have a larger elastic deformation regime (i.e., a larger amount of elastic deformation before plastic deformation) than the body material. In some embodiments, the arm(s) and the seal body 302 of the annular seal 300 may be made of a single material. For example, the arm(s) 304, 306 and the seal body 302 may be integrally formed with one another in a monolithic construction.

[0051] In some embodiments, the annular seal 300 includes a support material that is different from the arm material. For example, the support protrusion(s) 310 may be formed by application of a support material to a surface of the arm 304, 306 (e.g., inner arm or outer arm). In some examples, the support material may be harder than the arm material to limit and / or reduce wear to the support protrusion 310. In some examples, the support material may be a lubricious materialto provide a relatively low coefficient of friction during mating of the support protrusion 310 with the surface. In some examples, the support material may be more compliant than the arm material to conform to the adjacent surface and scrape the adjacent surface and provide a clean adjacent surface for the fluid seal.

[0052] In some embodiments, the annular seal 300 includes a seal material that is different from the support material. For example, the seal material may be the arm material, and the support material is a second material different from the arm material. In some examples, the seal material may be a second material, and the support material is the arm material. In some examples, the seal material and the support material may both be different from the arm material. In some embodiments, the seal material and the support material may be the same as one another and different from the arm material.

[0053] An annular seal 300, according to some embodiments of the present disclosure, may be used in a dynamic application where the dynamic surface moves axially relative to the annular seal 300 in both axial directions. In some embodiments, an annular seal 300 includes a second support protrusion 324 to clean the dynamic surface in the opposite direction during repeated stabs. For example, the seal protrusion 308 is located axially between a first support protrusion 310 and a second support protrusion 324 on the same arm 304, 306. In some embodiments, one or both of the first support protrusion 310 and the second support protrusion 324 may contact the adjacent surface while the annular seal 300 is in the compressed state. For example, the first support protrusion 310 and the second support protrusion 324 may create a zone 326 therebetween in which debris accumulation is blocked and / or reduced to enable the seal protrusions to maintain a fluid seal with the adjacent surface during movement of the dynamic surface relative to the annular seal 300.

[0054] In some embodiments, the seal force may be greater than at least one of the support forces (e.g., a first support force applied by the first support protrusion 310 and / or a second support force applied by the second support protrusion 324). In some embodiments, the seal force may be greater than both of the support forces. In some embodiments, the seal force may be less than the support forces, for example when pressure is applied to the annular seal 300. In some embodiments, the seal pressure may be greater than at least one of the support pressures (e.g., a first support pressureapplied by the first support protrusion 310 and / or a second support pressure applied by the second support protrusion 324). In some embodiments, the seal pressure may be greater than both of the support pressures. In some embodiments, the seal pressure may be less than the support pressures.

[0055] FIG. 7 is a flowchart of a method 400 of sealing an annular volume (e.g., in a downhole environment), according to some embodiments of the present disclosure. The method 400 includes providing an annular seal, according to any embodiments described herein, on a static surface at 402. In some embodiments, the static surface may be an outer surface (e.g., inner diameter of a pipe or other element) relative to the annular seal. In some embodiments, the static surface may be an inner surface (e.g., outer diameter of a pipe or other element) relative to the annular seal.

[0056] The method further includes moving a dynamic surface radially opposite to the static surface in an axial direction relative to the annular seal at 404. In some embodiments, the axial movement of the dynamic surface relative to the annular seal may result in the annular seal contacting a portion of the dynamic surface with a support protrusion and deforming an arm of the annular seal. In some embodiments, the support protrusion, optionally, axially centers (e.g., in the radial direction) the annular seal relative to the dynamic surface at 406. In some embodiments, the support protrusion, optionally, scrapes at least a portion of a surface with which the support protrusion contacts to produce a scraped dynamic surface at 408. In some embodiments, the support protrusion may, optionally, scrape at least a portion of a surface with which the support protrusion contacts to produce a scraped static surface during initial placement of the seal.

[0057] In some embodiments, continued axial movement of the dynamic surface relative to the annular seal causes the support protrusion to continue sliding on the dynamic surface until a seal protrusion of the annular seal contacts the dynamic surface at 410. In some embodiments, the seal protrusion may contact the scraped dynamic surface. The seal protrusion applies a seal pressure to the dynamic surface to create a fluid seal between the annular seal and the dynamic surface.

[0058] In some embodiments, contact between the seal protrusion and the dynamic surface produces a deformation (elastic and / or plastic deformation) of the arm supporting the seal protrusion relative to a seal body of the annular seal at 412. In some embodiments, the deformation of the arm may lift the support protrusion from the dynamic surface. For example, deformation ofthe arm between the support protrusion and the seal body may cause the support protrusion to lift from the dynamic surface.

[0059] In some embodiments, the deformation of the arm may not lift the support protrusion from the dynamic surface. For example, deformation of the arm between the seal protrusion and the support protrusion may not cause the support protrusion to lift from the dynamic surface. In some embodiments, the support pressure may be zero, as the support protrusion is not in contact with the dynamic surface. In some embodiments, the support pressure may be greater than zero, as the support protrusion is in contact with the dynamic surface. In some embodiments, the seal pressure of the seal protrusion against the dynamic surface may be greater than the support pressure while the annular seal is in the compressed state.

[0060] Annular seals according to at least some embodiments of the present disclosure may provide an improved and robust fluid seal in a downhole environment. In some embodiments, annular seals according to the present disclosure may center the dynamic surface during engagement of the seal. In some embodiments, annular seals according to the present disclosure may scrape the dynamic surface to provide a clean surface against which the annular seal may contact and create the fluid seal.

[0061] As described in further detail below, the seal assemblies may include an axial seal assembly configured to seal an inner tube section and an outer tube section. The axial seal assembly may include slidable seal elements and one or more springs. The springs may apply axial force to produce axial compression of the slidable seal elements. The slidable seal elements may radially deflect between the inner tube section and the outer tube section, thereby creating tight sealing contact of the slidable seal elements with the inner tube section and the outer tube section. Such an embodiment may increase the efficiency of the axial seal assembly for various temperatures and / or wear of the axial seal assembly.

[0062] FIG. 8 is a partial side cross-sectional view of an axial seal assembly 500 according to an embodiment. The sliding seal elements 502 may be axially moveably and slidably engaged with the inner tube section 504 (e.g., the inner surface) and the outer tube section 506 (e.g., the outer surface). The sliding seal elements 502 are retained on the inner tube section 504 by a first retaining ring 508 and a second retaining ring 510. The first retaining ring 508 and the secondretaining ring 510 may be secured to the inner tube section 504 and / or the outer tube section 506 in any suitable manner. For example, as depicted in FIG. 8, the first retaining ring 508 is threaded to engaged with the inner tube section 504. In a further example, as illustrated in FIG. 8, the second retaining ring 510 is split, seated in a groove 512 defined in the inner tube section 504, and secured with a clip 514. In some embodiments, the inner tube section 504, the outer tube section 506, the first retaining ring 508, the second retaining ring 510, and the clip 514 may be metallic (e.g., steel, bronze, brass, cast iron, copper, etc.). In some embodiments, the first retaining ring 508 or the second retaining ring 510 may be integral with the inner tube section 504 (not shown). In some embodiments, the first retaining ring 508 and / or the second retaining ring 510 may be snap rings (not shown). The sliding seal elements 502 may may seal to isolate a first space 516 from a second space 518 between the inner tube section 504 and the outer tube section 506. Thus, the sliding seal elements 502 may block fluid communication between the first space 516 and the second space 518.

[0063] Referring again to FIG. 8, the sliding seal elements 502 include a dual-nosed ring 520, a first set of two or more polymeric rings forming a first chevron stack 522, and a second set of two or more polymeric rings forming a second chevron stack 524. The dual-nosed ring 520 is disposed between the first chevron stack 522 and the second chevron stack 524. The dual-nosed ring 520, the first chevron stack 522, and the second chevron stack 524 may be formed of polymers (e.g., thermoplastic, polypropylene, polyethylene, nylon, nitrile, elastomer, fluoroelastomer, silicone, ethylene propylene diene monomer (EPDM), etc.). The sliding seal elements 502 further include a first spring 526 disposed between a first spacer ring 528 and a first spacer collar 530. The sliding seal elements 502 also include a second spring 532 disposed between a second spacer ring 534 and a second spacer collar 536. For example, the first chevron stack 522 is disposed between the first spacer ring 528 and the dual-nosed ring 520. Similarly, the second chevron stack 524 is disposed between the second spacer ring 534 and the dual-nosed ring 520.

[0064] In the illustrated embodiment of FIG. 8, the first spring 526 and the second spring 532 are coil springs. The first spring 526 may be any suitable type of spring configured to axially urge the first spacer ring 528 away from the first spacer collar 530. Similarly, the second spring 532 may be any suitable type of spring configured to axially urge the second spacer ring 534 away from the second spacer collar 536. Thus, the first spring 526 and / or the second spring 532 may becoil springs, leaf springs, torsion springs, wave springs, etc. In some embodiments, the first spring 526 and / or the second spring 532 may be constructed from non-metallic material that stores energy when deformed. For example, the first spring 526 and / or the second spring 532 may a rubber compression ring or bearing. In some embodiments, the first spring 526 and / or the second spring 532 may be a sealed gas pocket (e.g., a gas spring). In some embodiments, the first spring 526 and the second spring 532 may be substantially identical. In some embodiments, the first spring 526 and the second spring 532 may differ in form and / or spring rate.

[0065] In the illustrated embodiment of FIG. 8, the first chevron stack 522 and the second chevron stack 524 are mirror images of one another and thus include the same components. Consequently, the first chevron stack 522 and the second chevron stack 524 each include a trough ring 540, a crescent ring 542, and one or more chevron rings 544. In some embodiments, respective components of the first chevron stack 522 and the second chevron stack 524 may differ. The trough ring 540, the crescent ring 542, and the chevron rings 544 may be formed of a polymer. The trough ring 540 of the first chevron stack 522 abuts the first spacer ring 528. Similarly, the trough ring 540 of the second chevron stack 524 abuts the second spacer ring 534. Each trough ring 540 defines an indent 546, which receives an arc 548 of the crescent ring 542. Further, each crescent ring 542 defines a channel 550, which receives a tip 552 of the chevron ring 544. Each chevron ring 544 defines a groove 554, which is configured to receive the tip 552 of a neighboring chevron ring 544. Thus, in some embodiments, multiple chevron rings 544 may nest together via the tips 552 and the grooves 554. Additionally, the groove 554 is configured to receive a nose 556 of the dual-nosed ring 520. The noses 556 of the dual-nosed ring 520 axially oppose one another. Thus, the first chevron stack 522 and the second chevron stack 524 each engage the dual-nosed ring 520 via the grooves 554 and the noses 556. In various embodiments, the nose 556 may be more or less pointed than in the illustrated embodiment of FIG. 3 to vary engagement depth with the groove 554. In some embodiments, the crescent ring 542 may be an anti-extrusion ring designed to provide redundancy in the axial seal assembly 500.

[0066] Referring again to FIG. 8, the first spacer collar 530 and the second spacer collar 536 are mirror images of one another and thus include the same components. Consequently, the first spacer collar 530 and the second spacer collar 536 each include a support collar 560 extending axially from a presser ring 562 toward the dual-nosed ring 520. The support collar 560 of the firstspacer collar 530 captures, supports, aligns, and controls maximum compression of the first spring 526. The presser ring 562 of the first spacer collar 530 abuts the first spring 526 and the first retaining ring 508. Thus, the first retaining ring 508 and the presser ring 562 of the first spacer collar 530 provide a hard stop for the first spring 526. The first spring 526 extends beyond and is radially inside the support collar 560 of the first spacer collar 530. Similarly, the support collar 560 of the second spacer collar 536 captures, supports, and aligns the second spring 532. The presser ring 562 of the second spacer collar 536 abuts the second spring 532 and the second retaining ring 510. Thus, the second retaining ring 510 and the presser ring 562 of the second spacer collar 536 provide a hard stop for the second spring 532. The second spring 532 extends beyond and is radially inside the support collar 560 of the second spacer collar 536. In some embodiments, the first spacer collar 530 and the second spacer collar 536 may be anti-extrusion rings designed to provide redundancy in the axial seal assembly 500.

[0067] Looking further at FIG. 8, in operation, the first spring 526 may urge the first spacer ring 528 axially away from the first spacer collar 530 and toward the second spacer ring 534. Similarly, the second spring 532 may urge the second spacer ring 534 axially away from the second spacer collar 536 and toward the first spacer ring 528. Thus, the first spring 526 and the second spring 532 may urge the first spacer ring 528 and the second spacer ring 534 toward one another. Accordingly, the dual-nosed ring 520, the first chevron stack 522, and the second chevron stack 524 may be axially compressed together between the first spacer ring 528 and the second spacer ring 534. Further, under axial compression, the dual-nosed ring 520, the first chevron stack 522, and the second chevron stack 524 may radially deflect between the inner tube section 504 and the outer tube section 506. Consequently, the dual-nosed ring 520, the first chevron stack 522, and the second chevron stack 524 may tightly sealably and slidably engage the inner tube section 504 and the outer tube section 506. Thus, the first spring 526 and the second spring 532 may aid in maintaining tight sealing contact of the dual-nosed ring 520, the first chevron stack 522, and the second chevron stack 524 with the inner tube section 504 and the outer tube section 506 as the dual-nosed ring 520, the first chevron stack 522, and the second chevron stack 524 wear, age, experience hot and cold temperature extremes, and / or experience rapid temperature changes.

[0068] FIG. 9 is a partial side cross-sectional view of an axial seal assembly 600 according to an embodiment. The axial seal assembly 600 includes sliding seal elements 602 axially moveablyand slidably engaged with the inner tube section 504 and the outer tube section 506. The sliding seal elements 602 are retained on the inner tube section 504 by the first retaining ring 508 and the second retaining ring 510, as described above with reference to FIG. 8. The sliding seal elements 602 may seal to isolate the first space 516 from the second space 518 between the inner tube section 504 and the outer tube section 506. Thus, the sliding seal elements 602 may block fluid communication between the first space 516 and the second space 518.

[0069] Referring again to FIG. 9, the sliding seal elements 602 include a first taper ring 604 between the first chevron stack 522 and the first spring 526’. Similarly, the sliding seal elements 602 include a second taper ring 606 between the second chevron stack 524 and the second spring 532’. The first taper ring 604 and the second taper ring 606 are mirror images of one another and thus have the same features. The first taper ring 604 and the second taper ring 606 may be formed of a polymer (e.g., thermoplastic, polypropylene, polyethylene, nylon, elastomer, nitrile, fluoroelastomer, silicone, ethylene propylene diene monomer (EPDM), etc.). The sliding seal elements 602 further include the first spacer ring 528, the second spacer ring 534, and a carrier collar 608. The carrier collar 608 is located between the first spring 526’ and the second spring 532’.

[0070] In the illustrated embodiment of FIG. 9, the first spring 526’ and the second spring 532’ are coil springs, as explained above with reference to FIG. 8. The first spring 526’ abuts and engages the first taper ring 604. The first spring 526’ may be any suitable type of spring configured to axially urge the first taper ring 604 away from the carrier collar 608. Similarly, the second spring 532’ abuts and engages the second taper ring 606. The second spring 532’ may be any suitable type of spring configured to axially urge the second taper ring 606 away from the carrier collar 608. Thus, the first spring 526’ and / or the second spring 532’ may be coil springs, leaf springs, torsion springs, wave springs, etc. In some embodiments, the first spring 526’ and / or the second spring 532’ may be constructed from non-metallic material that stores energy when deformed. For example, the first spring 526’ and / or the second spring 532’ may a rubber compression ring or bearing. In some embodiments, the first spring 526’ and the second spring 532’ may be substantially identical. In some embodiments, the first spring 526’ and the second spring 532’ may differ in form and / or spring rate. In some embodiments, the first spring 526’ and / or the second spring 532’ may be a sealed gas pocket (e.g., a gas spring).

[0071] Remaining with FIG. 9, each of the first taper ring 604 and the second taper ring 606 includes a nose 610 opposite a flat side 612. The grooves 554 are configured to receive the noses 610. Thus, the first chevron stack 522 engages the first taper ring 604 via the groove 554 and the nose 610. Similarly, the second chevron stack 524 engages the second taper ring 606 via the groove 554 and the nose 610. In various embodiments, the nose 610 may be more or less pointed than in the embodiment of FIG. 9 to vary engagement depth with the groove 554. Further, the first spring 526’ and the second spring 532’ abut the flat sides 612 of the first taper ring 604 and the second taper ring 606, respectively.

[0072] Referring again to FIG. 9, the carrier collar 608 includes a presser ring 614 extending radially inwardly from a support collar 616. The presser ring 614 is located approximately axially medially along the support collar 616. The support collar 616 captures, supports, and aligns the first spring 526’ and the second spring 532’. The presser ring 614 is disposed between and abuts the first spring 526’ and the second spring 532’. Thus, the presser ring 614 provides a base for the first spring 526’ and the second spring 532’. The first spring 526’ and the second spring 532’ extend beyond and are radially inside the support collar 616.

[0073] Looking further at FIG. 9, in operation, the first spring 526’ may urge the first taper ring 604 axially away from the carrier collar 608 and toward the first retaining ring 508. Similarly, the second spring 532’ may urge the second taper ring 606 axially away from the carrier collar 608 and toward the second retaining ring 510. Thus, the first spring 526’ and the second spring 532’ may urge the first chevron stack 522 and the second chevron stack 524 away from one another. Accordingly, the first taper ring 604 and the first chevron stack 522 may be axially compressed between the carrier collar 608 and the first retaining ring 508. Likewise, the second taper ring 606 and the second chevron stack 524 may be axially compressed together between the carrier collar 608 and the second retaining ring 510. Thus, the first taper ring 604, the second taper ring 606, the first chevron stack 522, and the second chevron stack 524 may be axially compressed between the first retaining ring 508 and the second retaining ring 510. Further, under axial compression, the first taper ring 604, the second taper ring 606, the first chevron stack 522, and the second chevron stack 524 may radially deflect between the inner tube section 504 and the outer tube section 506. Consequently, the first taper ring 604, the second taper ring 606, the first chevron stack 522, and the second chevron stack 524 may tightly sealably and slidably engage the innertube section 504 and the outer tube section 506. Thus, the first spring 526’ and the second spring 532’ may aid in maintaining tight sealing contact of the first taper ring 604, the second taper ring 606, the first chevron stack 522, and the second chevron stack 524 with the inner tube section 504 and the outer tube section 506 as the first taper ring 604, the second taper ring 606, the first chevron stack 522, and the second chevron stack 524 wear, age, experience hot and cold temperature extremes, and / or experience rapid temperature changes.

[0074] FIG. 10 is a partial side cross-sectional view of an axial seal assembly 700 according to an embodiment. The axial seal assembly 700 includes sliding seal elements 702 axially moveably and slidably engaged with the inner tube section 504 and the outer tube section 506. The sliding seal elements 702 are retained on the inner tube section 504 by the first retaining ring 508 and the second retaining ring 510, as described above with reference to FIG. 8. The sliding seal elements 702 may seal to isolate the first space 516 from the second space 518 between the inner tube section 504 and the outer tube section 506. Thus, the sliding seal elements 702 may block fluid communication between the first space 516 and the second space 518.

[0075] Referring again to FIG. 10, the sliding seal elements 702 include a first inner spring 704 and a first outer spring 706 disposed between the first taper ring 604 and a backing collar 708. Similarly, the sliding seal elements 702 include a second inner spring 710 and a second outer spring 712 disposed between the second taper ring 606 and the backing collar 708. As described above with reference to FIG. 9, the first taper ring 604 and the second taper ring 606 are mirror images of one another and are formed of a polymer. The sliding seal elements 702 further include the first spacer ring 528 and the second spacer ring 534. The backing collar 708 is located between the first inner spring 704 and the second inner spring 710. Similarly, the backing collar 708 is located between the first outer spring 706 and the second outer spring 712. The backing collar 708 is cruciform in cross-section and includes a first rim 714 and a second rim 716 extending axially from a presser ring 718 toward the first retaining ring 508 and the second retaining ring 510, respectively.

[0076] In the illustrated embodiment of FIG. 10, the first inner spring 704, the second inner spring 710, the first outer spring 706, and the second outer spring 712 are coil springs, as explained above with reference to FIG. 9. The first inner spring 704 and the first outer spring 706 abut andengage the first taper ring 604 via the flat side 612. The first inner spring 704 and the first outer spring 706 may be any suitable type of spring configured to axially urge the first taper ring 604 away from the backing collar 708. Similarly, the second inner spring 710 and the second outer spring 712 abut and engage the second taper ring 606 via the flat side 612. The second inner spring 710 and the second outer spring 712 may be any suitable type of spring configured to axially urge the second taper ring 606 away from the backing collar 708. Thus, the first inner spring 704, the second inner spring 710, the first outer spring 706, and / or the second outer spring 712 may be coil springs, leaf springs, torsion springs, wave springs, etc. In some embodiments, the first inner spring 704, the second inner spring 710, the first outer spring 706, and / or the second outer spring 712 may be constructed from non-metallic material that stores energy when deformed. For example, the first inner spring 704, the second inner spring 710, the first outer spring 706, and / or the second outer spring 712 may a rubber compression ring or bearing. In some embodiments, the first inner spring 704, the second inner spring 710, the first outer spring 706, and / or the second outer spring 712 may be substantially identical. In some embodiments, the first inner spring 704, the second inner spring 710, the first outer spring 706, and / or the second outer spring 712 may differ in form and / or spring rate. In some embodiments, the first inner spring 704, the second inner spring 710, the first outer spring 706, and / or the second outer spring 712 may be a sealed gas pocket (e.g., a gas spring).

[0077] Remaining with FIG. 10, the first chevron stack 522 engages the first taper ring 604 via the groove 554 and the nose 610, as described above with reference to FIG. 9. Similarly, the second chevron stack 524 engages the second taper ring 606 via the groove 554 and the nose 610, as described above with reference to FIG. 9.

[0078] Referring again to FIG. 10, the presser ring 718 of the backing collar 708 extends radially. The first rim 714 and the second rim 716 oppose one another. Further, the first rim 714 and the second rim 716 are located approximately radially medially along the presser ring 718. The first rim 714 captures, supports, and aligns the first inner spring 704 and the first outer spring 706. The second rim 716 captures, supports, and aligns the second inner spring 710 and the second outer spring 712. The presser ring 718 is disposed between the first inner spring 704 and the second inner spring 710. Similarly, the presser ring 718 is disposed between and abuts the first outer spring 706 and the second outer spring 712. Thus, the presser ring 718 provides a base for the first 1inner spring 704, the second inner spring 710, the first outer spring 706, and the second outer spring 712. The first inner spring 704 and the first outer spring 706 extend beyond the first rim 714. Likewise, the second inner spring 710 and the second outer spring 712 extend beyond the second rim 716. The first inner spring 704 and the second inner spring 710 are radially inside the first rim 714 and the second rim 716, respectively. The first outer spring 706 and the second outer spring 712 are radially outside the first rim 714 and the second rim 716.

[0079] Looking further at FIG. 10, in operation, the first inner spring 704 and the first outer spring 706 may urge the first taper ring 604 axially away from the backing collar 708 and toward the first retaining ring 508. Similarly, the second inner spring 710 and the second outer spring 712 may urge the second taper ring 606 axially away from the backing collar 708 and toward the second retaining ring 510. Thus, the first inner spring 704, the second inner spring 710, the first outer spring 706, and the second outer spring 712 may urge the first chevron stack 522 and the second chevron stack 524 away from one another. Accordingly, the first taper ring 604 and the first chevron stack 522 may be axially compressed between the backing collar 708 and the first retaining ring 508. Likewise, the second taper ring 606 and the second chevron stack 524 may be axially compressed together between the backing collar 708 and the second retaining ring 510. Thus, the first taper ring 604, the second taper ring 606, the first chevron stack 522, and the second chevron stack 524 may be axially compressed between the first retaining ring 508 and the second retaining ring 510.

[0080] Remaining with FIG. 10, under axial compression, the first taper ring 604, the second taper ring 606, the first chevron stack 522, and the second chevron stack 524 may radially deflect between the inner tube section 504 and the outer tube section 506. Consequently, the first taper ring 604, the second taper ring 606, the first chevron stack 522, and the second chevron stack 524 may tightly sealably and slidably engage the inner tube section 504 and the outer tube section 506. Thus, the first inner spring 704, the second inner spring 710, the first outer spring 706, and the second outer spring 712 may aid in maintaining tight sealing contact of the first taper ring 604, the second taper ring 606, the first chevron stack 522, and the second chevron stack 524 with the inner tube section 504 and the outer tube section 506 as the first taper ring 604, the second taper ring 606, the first chevron stack 522, and the second chevron stack 524 wear, age, experience hot and cold temperature extremes, and / or experience rapid temperature changes.

[0081] An annular seal, for example as illustrated in FIGS. 2-6, may be used in a pair with additional sealing elements axially therebetween to provide a robust and reliable fluid axial seal assembly, as illustrated in FIGS. 11 and 12. In some embodiments, the axial seal assembly may include a first annular seal and a second annular seal. In some embodiments, the first annular seal and the second annular seal may be the same. In some embodiments, the first annular seal and the second annular seal may be different. The axial seal assembly may additionally include at least a first support ring (e.g., a spacer collar, a trough ring) proximate to the first annular seal and configured to axially support the first annular seal, and a second support ring (e.g., a spacer collar, a trough ring) proximate to the second annular seal and configured to axially support the second annular seal.

[0082] FIG. 11 is a side cross-sectional view of a portion of an embodiment of an axial seal assembly 800 including the annular seal of FIG. 2. The sliding seal elements 802 are axially moveably and slidably engaged with the inner tube section 504 and the outer tube section 506. The sliding seal elements 802 are retained on the inner tube section 504 by a first annular seal 804 and a second annular seal 806. The annular seals 804, 806 are oriented with a seal body 808 of each annular seal 804, 806 positioned axially outward from a first spacer collar 814 and a second spacer collar 816, respectively, of the sliding seal elements 802. Arms 810, 812 of each annular seal 804, 806 protrude axially inwardly from the seal body 808. The sliding seal elements 802 and the annular seals 804, 806 may seal to isolate the first space 516 from the second space 518 between the inner tube section 504 and the outer tube section 506. Thus, the sliding seal elements 802 and the annular seals 804, 806 may block fluid communication between the first space 516 and the second space 518.

[0083] In the illustrated embodiment of FIG. 11 , the sliding seal elements 802 include a dualnosed ring 520, a first set of two or more polymeric rings forming a first chevron stack 522, and a second set of two or more polymeric rings forming a second chevron stack 524. The dual-nosed ring 520 is disposed between the first chevron stack 522 and the second chevron stack 524. The first chevron stack 522 is disposed between the first spacer collar 814 and the dual-nosed ring 520. The second chevron stack 524 is disposed between the second spacer collar 816 and the dual-nosed ring 520.

[0084] The first chevron stack 522 and the second chevron stack 524 are mirror images of one another and thus include the same components, as described with respect to FIG. 8. For example, as illustrated in FIG. 11 , the first chevron stack 522 and the second chevron stack 524 each includes a crescent ring 542 and one or more chevron rings 544. In some embodiments, the spacer collars 814, 816 each have an axial protrusion 818 positioned between the inner arm 810 and the outer arm 812 of a respective annular seal 804, 806. In some embodiments, at least one axial protrusion 818 contacts the respective seal body 808 and axially supports the respective seal body 808. In some embodiments, at least one axial protrusion 818 contacts the inner arm 810 and / or the outer arm 812 of the respective annular seal 804, 806 and supports the arm(s) 810, 812 in the radial direction (e.g., transverse to the axial direction). Each spacer collar 814, 816 also defines an indent 820, which receives an arc 548 of the respective crescent ring 542. Further, each crescent ring 542 defines a channel 550, which receives a tip 552 of the respective chevron ring 544. Each chevron ring 544 defines a groove 554, which is configured to receive the tip 552 of a neighboring chevron ring 544. Thus, in some embodiments, the chevron rings 544 of each set nest together via the tips 552 and the grooves 554. Additionally, each groove 554 is configured to receive a nose 556 of the dual-nosed ring 520. The noses 556 of the dual-nosed ring 520 axially oppose one another. Thus, the first chevron stack 522 and the second chevron stack 524 engage the dual-nosed ring 520 via the grooves 554 of the innermost chevron rings 544 and the noses 556 of the dual-nosed ring 520.

[0085] Looking at FIG. 11, in operation, each spacer collar 814, 816 may transmit force from the respective annular seal 804, 806 (such as an axial force applied to the annular seal by a fluid) to the dual-nosed ring 520 via the first and second chevron stacks. The dual-nosed ring 520 and the chevron stacks may receive axial force from each spacer collar 814, 816, and, upon axial compression, expand radially against the inner tube section 504 and outer tube section 506 to further seal the volume between the inner tube section 504 and the outer tube section 506. In some embodiments, the dual-nosed ring may be a thermoplastic or elastomeric material that enables repeated cycling of deformation with limited or no fatigue.

[0086] FIG. 12 is a side cross-sectional view of a portion of an embodiment of an axial seal assembly 900 including the annular seal of FIG. 2. The sliding seal elements 902 are axially moveably and slidably engaged with the inner tube section 504 and the outer tube section 506. The sliding seal elements 902 are retained on the inner tube section 504 by a first annular seal 904and a second annular seal 906. Each annular seal 904, 906 is oriented with the seal body 908 toward the sliding seal elements 902 and the arms 910, 912 protruding in the axial direction away from the sliding seal elements 902. Each trough ring 540 abuts the seal body 908 of a respective annular seal in the axial direction to support the seal body 908 in the axial direction. In some embodiments, each trough ring 540 is non-metal, such as a thermoplastic or elastomeric material with a greater compliance than the respective annular seal 904, 906.

[0087] In the illustrated embodiment of FIG. 12, the sliding seal elements 902 include a dualnosed ring 520, a first set of two or more polymeric rings forming a first chevron stack 522, and a second set of two or more polymeric rings forming a second chevron stack 524. The dual-nosed ring 520 is disposed between the first chevron stack 522 and the second chevron stack 524. The first chevron stack 522 is disposed between the first annular seal 904 and the dual-nosed ring 520. The second chevron stack 524 is disposed between the second annular seal 906 and the dual-nosed ring 520.

[0088] The first chevron stack 522 and the second chevron stack 524 are mirror images of one another and thus include the same components, as described with respect to FIG. 8. For example, as illustrated in FIG. 12, the first chevron stack 522 and the second chevron stack 524 each includes a trough ring 540, a crescent ring 542, and one or more chevron rings 544. Each trough ring 540 defines an indent 546, which receives an arc 548 of the respective crescent ring 542. Further, each crescent ring 542 defines a channel 550, which receives a tip 552 of the respective chevron ring 544. Each chevron ring 544 defines a groove 554, which is configured to receive the tip 552 of a neighboring chevron ring 544. Thus, in some embodiments, the chevron rings 544 of each set nest together via the tips 552 and the grooves 554. Additionally, each groove 554 is configured to receive a nose 556 of the dual-nosed ring 520. The noses 556 of the dual-nosed ring 520 axially oppose one another. Thus, the first chevron stack 522 and the second chevron stack 524 engage the dual-nosed ring 520 via the grooves 554 of the innermost chevron rings 544 and the noses 556 of the dual-nosed ring 520.

[0089] Looking at FIG. 12, in operation, each chevron stack 522, 524 may transmit force from the respective annular seal 904, 906 (such as an axial force applied to the annular seal by a fluid) to the dual-nosed ring 520. The dual-nosed ring 520 and the chevron stacks may receive the axialforce and, upon axial compression, expand radially against the inner tube section 504 and the outer tube section 506 to further seal the volume between the inner tube section 504 and the outer tube section 506. In some embodiments, the dual-nosed ring 520 may be a thermoplastic or elastomeric material that enables repeated cycling of deformation with limited or no fatigue.

[0090] As described in further detail below, the seal assemblies may include a valve seal assembly configured to be used in a flow control valve. Undesirable fluid flow through components of the flow control valve (e.g., leak paths) may reduce the effectiveness of the flow control valve. As such, the flow control valve may include valve sealing assemblies to control, reduce, or eliminate fluid flow through potential leak paths of the flow control valve. For example, the flow control valve may have one or more valve seal assemblies disposed between a piston and a choke sleeve of the flow control valve.

[0091] FIG. 13 is a cross-sectional view of an embodiment of a flow control valve 1000. FIGS. 14A-E are detailed cross-sectional views of the portion of the flow control valve 1000 shown in box 14 of FIG. 13. FIGS. 14A-E may show additional subcomponents not pictured in FIG. 13; thus, FIGS. 13 and 14A-E may be referenced when describing the components and the subcomponents of the flow control valve.

[0092] As illustrated in FIG. 13, the flow control valve 1000 includes a housing 1002, a choke sleeve 1004, a piston 1006, a spacer 1008, a choke seal 1010, and a valve seal assembly 1012. The flow control valve 1000 may be included in a tubular string disposed in a wellbore and may be used to control flow from the exterior of the flow control valve 1000 into an interior flow passage 1014 of the flow control valve 1000, which may be in communication with a production tubing string.

[0093] The housing 1002 may be a generally tubular body with one or more orifices 1016 circumferentially disposed around the housing 1002. The one or more orifices 1016 may enable selective fluid communication between the interior flow passage 1014 of the flow control valve 1000 and an exterior of the flow control valve 1000. The interior flow passage 1014 is an open volume (e.g., bore) within the flow control valve 1000. The interior flow passage 1014 is partially defined by an inner surface 1018 of the housing 1002 and an inner surface 1020 of the choke sleeve 1004. The inner surface 1018 of the housing 1002 includes the entirety of the surfaces on theinterior of the housing 1002 regardless of diameter at individual points. In some embodiments, the inner surface 1018 of the housing 1002 includes various profiles to aid in positioning the remaining components of the flow control valve 1000, such as a shoulder 1022 which aids in positioning the choke seal 1010.

[0094] The choke sleeve 1004 is disposed radially within the housing 1002 such that an outer surface 1024 of the choke sleeve 1004 engages with the inner surface 1018 of the housing 1002. The choke sleeve 1004 includes one or more choking orifices 1026 extending from the outer surface 1024 to the inner surface 1020 that permit fluid communication between the one or more orifices 1016 of the housing 1002 and the interior flow passage 1014 of the flow control valve 1000. In other words, the one or more choking orifices 1026 enable fluid communication between the exterior of the flow control valve 1000 and the interior flow passage 1014 when the piston 1006 is positioned to permit fluid communication.

[0095] The spacer 1008 is disposed within the housing 1002 and is engaged with the inner surface 1018 of the housing 1002. The spacer 1008 includes a first end 1028 and a second end 1030. The first end 1028 of the spacer 1008 is adjacent to an end 1032 of the choke sleeve 1004 such that the first end 1028 of the spacer 1008 abuts the end 1032 of the choke sleeve 1004. In some embodiments, the spacer 1008 and the choke sleeve 1004 are integral to one another.

[0096] The spacer 1008 includes a recess 1034. As shown in FIG. 14A, the recess 1034 of the spacer 1008 includes a first surface 1102, a second surface 1104, and a third surface 1106. The first surface 1102 tapers from the inner surface 1020 of the choke sleeve 1004 to the second surface 1104. The third surface 1106 is angled with respect to the second surface 1104 to create a shoulder and define the end of the recess 1034. In some embodiments, the second surface 1104 may be planar. In other embodiments, the second surface 1104 may be a tapered surface. In some embodiments, the third surface 1106 is perpendicular to the second surface 1104.

[0097] In some embodiments, the inner surface 1020 of the choke sleeve includes a profiled portion 1108 (e.g. a tapered portion) that leads to the first surface 1102 of the recess 1034.

[0098] Referring back to FIG. 13, the choke seal 1010 is disposed within the housing 1002, and an outer surface 1036 of the choke seal 1010 is engaged with the inner surface 1018 of the housing1002. The choke seal 1010 further includes a first end 1038, a second end 1040, and an inner surface 1042. The first end 1038 of the choke seal 1010 is adjacent to the second end 1030 of the spacer 1008 such that the first end 1038 of the choke seal 1010 abuts the second end 1030 of the spacer 1008. The second end 1040 of the choke seal 1010 abuts and is engaged with the shoulder 1022 of the housing 1002. The inner surface 1042 of the choke seal 1010 may seal against the piston 1006 when the piston 1006 is in the fully closed position (an example of a fully closed position is shown in FIG. 2C). Leakage between the piston 1006 and the choke sleeve 1004 (e.g., leakage through leakage gap 1044) may be controlled, reduced, or eliminated by the choke seal 1010 when the piston 1006 is in the fully closed position. In some embodiments, the choke seal 1010 may be made of a metallic material.

[0099] The piston 1006 is slidably disposed within the choke sleeve 1004. The outer surface 1046 of the piston 1006 includes a piston sealing surface 1048 and a groove 1050. In some embodiments, the piston sealing surface 1048 includes a tapered portion 1110 leading to the groove 1050 as shown in FIG. 14A. The valve seal assembly 1012 is disposed within the groove 1050 when the piston 1006 is in the first position, as shown in FIG. 14A.

[0100] In some embodiments, such as in FIG. 13, the piston 1006 is a multi-part piston that includes a first piston sleeve 1052 and a second piston sleeve 1054, with the groove 1050 being partially defined by the first piston sleeve 1052 and the second piston sleeve 1054. In some embodiments, the second piston sleeve 1054 may be made of carbide or include a portion formed from carbide. In some embodiments, the piston 1006 may be one monolithic piston.

[0101] As shown in FIG. 14A, the groove 1050 is defined by a first surface 1112 of the second piston sleeve 1054, a second surface 1114 of the second piston sleeve 1054, and a third surface 1116 of the first piston sleeve 1052. The first surface 1112 defines the base of the groove 1050, the second surface 1114 defines one end of the groove 1050 and is angled from the first surface 1112 to create a shoulder at one end of the groove 1050, and the third surface 1116 is angled from the first surface 1112 defining the end of the groove 1050 opposite the end defined by the second surface 1114. In embodiments in which the piston 1006 is monolithic, the first surface 1112, the second surface 1114, and the third surface 1116 are all surfaces of the monolithic piston 1006.

[0102] Referring back to FIG. 13, the valve seal assembly 1012 is engaged with the groove 1050 and the inner surface 1020 of the choke sleeve 1004 to control, reduce, or eliminate fluid flow through the leakage gap 1044. The valve seal assembly 1012 includes a first seal portion 1056 (e.g., first seal element) and a second seal portion 1058 (e.g., second seal element). In some embodiments, the second seal portion 1058 is a cap seal (hereinafter referred to as “cap seal 1058”) that may be compressed to a radially retracted position (as shown in FIG. 14 A) and expanded to a radially expanded position (as shown in FIG. 14C).

[0103] The first seal portion 1056 is disposed in the groove 1050 and carried by the movement of the piston 1006. In some embodiments, the first seal portion 1056 is an O-ring configured to seal against the cap seal 1058 and also bias the cap seal 1058 toward the radially expanded position. However, the first seal portion 1056 may be any number of sealing elements so long as the first seal portion 1056 may seal against the cap seal 1058 and bias the cap seal 1058 towards the radially expanded position.

[0104] The cap seal 1058 may have an uninstalled diameter larger than the inner diameter of the choke sleeve 1004 to facilitate a tight sealing engagement between the cap seal 1058 and the inner surface 1020 of the choke sleeve 1004 when the cap seal 1058 is compressed to the radially retracted position. The larger uninstalled diameter may also facilitate expanding the cap seal 1058 to the radially expanded position. As illustrated in FIGS. 14A, 14B, and 14D, the cap seal 1058 includes a first side 1118, a second side 1120, a first end 1122, and a second end 1124. The second side 1120 of the cap seal 1058 includes a first portion 1120a (e.g., planar portion) and a profiled portion 1120b (e.g., tapered portion).

[0105] In some embodiments, the cap seal 1058 may also include a body 1126 made of a material including, but not limited to, polyetheretherketone (PEEK). In some embodiments, the first end 1122 of the cap seal 1058 and the second end 1124 of the cap seal 1058 may be defined by metal caps on either end of the body 1126 of the cap seal 1058.

[0106] In some embodiments, an adapter 1060 is also disposed in the groove 1050 with the first seal portion 1056, in which the adapter 1060 abuts the third surface 1116 of the groove 1050. The adapter 1060 includes a top surface 1128 that is tapered such that the top surface 1128 has a smaller diameter on a first end that is closer to the first seal portion 1056 and a larger diameter at the endthat abuts the third surface 1116 of the groove 1050. In some embodiments, the adapter 1060 may be made of materials including, but not limited to, metal and PEEK. In some embodiments, the adapter 1060 may be integral to one or more parts of the piston 1006. The top surface 1128 may have a profile to facilitate the radial expansion of the cap seal 1058 and the radial retraction of the cap seal 1058. In some embodiments, the tapered portion 1110 of the piston sealing surface 1048 may cooperate with the profile of the top surface 1128 to facilitate the radial expansion and radial retraction of the cap seal 1058.

[0107] FIGS. 14A-E are detailed cross-sectional views of the flow control valve 1000 of FIG. 13, showing a sequence of moving the piston 1006 during operation of the flow control valve 1000, in accordance with aspects of the present disclosure. In operation, the piston 1006 may selectively open and / or close fluid communication between the exterior of the flow control valve 1000 and the interior flow passage 1014 via the one or more orifices 1016 of the housing 1002 and the one or more choking orifices 1026. The piston 1006 may be stopped at, or moved between, various positions relative to the choke sleeve 1004 to regulate and / or manage the choke characteristics, flow rate, and pressure differentials of the exterior of the flow control valve 1000 and the interior flow passage 1014. The piston 1006 may be positioned in a fully opened position in which fluid communication between the exterior of the flow control valve 1000 and the interior flow passage 1014 is enabled via the one or more orifices 1016 of the housing 1002 and all of the one or more choking orifices 1026. The piston 1006 may be positioned in a fully closed position, in which the piston 1006 blocks, eliminates, or inhibits fluid communication between the exterior of the flow control valve 1000 and the interior flow passage 1014 by covering and / or blocking all of the choking orifices 1026.

[0108] The piston 1006 may be moved to one or more positions between the fully open and fully closed position to selectively block, eliminate, reduce, or inhibit fluid communication between the exterior of the flow control valve 1000 and the interior flow passage 1014 through one or more of the choking orifices 1026. In such positions, fluid communication may be enabled via the one or more orifices 1016 and a select number of the one or more choking orifices 1026 to regulate and / or manage the choke characteristics, flow rate, and pressure differentials of the exterior of the flow control valve 1000 and the interior flow passage 1014. For example, in FIG. 13, the piston 1006 is in a first position covering all but one of the choking orifices 1026.

[0109] In some embodiments, the leakage gap 1044 exists between the piston sealing surface 1048 and the inner surface 1020 of the choke sleeve 1004, thereby enabling fluid communication between the exterior of the flow control valve 1000 and the interior flow passage 1014 even though the piston 1006 is in a position to selectively cover one or more of the choking orifices 1026. In other words, the leakage gap 1044 may enable undesired communication between the interior flow passage 1014 and the exterior of the flow control valve 1000. In some embodiments, particulates suspended in the fluid may be small enough to enter into the leakage gap 1044.

[0110] As such, the valve seal assembly 1012 may control, block, eliminate and / or inhibit fluid and particulate from flowing through the leakage gap 1044 at various positions of the piston 1006. For example, in FIG. 13, the piston 1006 is in an open position, which enables fluid communication between the at least one choking orifice 1026 of the choke sleeve 1004 and the interior flow passage 1014 via one choking orifice 1026 that is not covered by the piston 1006. In the open position, the valve seal assembly 1012 engages the inner surface 1020 of the choke sleeve 1004 to control, reduce, eliminate, and / or inhibit fluid flow through the leakage gap 1044. Further, when the piston 1006 is in the fully closed position, as shown in FIG. 14C, the choke seal 1010 controls, reduces, eliminates, and / or inhibits fluid and particulate from flowing through the leakage gap 1044.

[0111] FIG. 14A is a cross-sectional view of the valve seal assembly 1012, in which the piston 1006 of the flow control valve 1000 is in a first position. In the first position of the piston 1006, the valve seal assembly 1012 may control, reduce, eliminate, and / or inhibit fluid flow along arrow 1130 between the inner surface 1020 of the choke sleeve 1004 and the piston sealing surface 1048. The first seal portion 1056 is disposed in the groove 1050 and is sealingly engaged with the first surface 1112 of the groove 1050. The cap seal 1058 is in the radially retracted position compressed between the choke sleeve 1004 and the first seal portion 1056. The second side 1120 of the cap seal 1058 is sealingly engaged with the first seal portion 1056, in some embodiments, the second side 1120 of the cap seal 1058 is also sealingly engaged with the top surface 1128 of the adapter 1060, and the first side 1118 of the cap seal 1058 is sealingly engaged with the inner surface 1020 of the choke sleeve 1004, thereby controlling, reducing, eliminating, and / or inhibiting fluid flow through the leakage gap 1044.

[0112] The piston 1006 may be moveable from the first position to the fully closed position in the direction of arrow 1132. As the piston 1006 moves to the fully closed position, the cap seal 1058 may separate from the first seal portion 1056 such that the cap seal 1058 is retained in the recess 1034 of the spacer 1008 while the first seal portion 1056 continues to travel with the piston 1006 to place the first seal portion 1056 on the opposite side of the choke seal 1010 from the cap seal 1058.

[0113] FIG. 14B is a cross-sectional view of the valve seal assembly 1012, in which the piston 1006 of the flow control valve 1000 is in a second position (e.g., as the piston 1006 moves toward the fully closed position). As shown, the cap seal 1058 is partially expanded (e.g., in a partially radially extended position) into the recess 1034 of the spacer 1008. In the second position of the piston 1006, the valve seal assembly 1012 may control, reduce, eliminate, and / or inhibit fluid flow along arrow 1134. As the piston 1006 moves in the direction of arrow 1136 toward the fully closed position, the cap seal 1058 is blocked from moving in the direction of arrow 1136 past the recess 1034 of the spacer 1008 due to the interaction between the first end 1122 of the cap seal 1058 and the third surface 1106 of the spacer 1008. Thus, the expandability of the material of the cap seal 1058, and the interaction of the profiled portion 1120b of the cap seal 1058 with the tapered portion 1110 of the piston sealing surface 1048 and / or the tapered portion of the top surface 1128 of the adapter 1060 may guide the cap seal 1058 into the radially expanded position within the recess 1034 of the spacer 1008 as the piston 1006 moves toward the fully closed position. In some embodiments, the biasing force exerted on the second side 1120 of the cap seal 1058 by the first seal portion 1056 may facilitate moving the cap seal 1058 into the radially expanded position. For example, the first seal portion 1056 may expand the cap seal 1058 from the radially retracted position to enable the first end 1122 to engage with the third surface 1106, as shown in FIG. 14B. In some embodiments, the cap seal 1058 is itself biased toward the expanded position and springs outward into the recess 1034 to facilitate engaging the first end 1122 with the third surface 1106, as shown in FIG. 14B. In some embodiments, electrical or other mechanical components may cause the cap seal 1058 to be expanded into the radially retracted position within the recess 1034 of the spacer 1008. Similarly, these electrical or mechanical components may similarly be used to facilitate the retraction of the cap seal 1058 as the piston 1006 moves away from the fully closed position to enable communication through at least one of the orifices 1026.

[0114] Also, as the piston 1006 moves in the direction of arrow 1136 from the second position to the fully closed position, the piston 1006, including the groove 1050 and the first seal portion 1056, may slide under the inner surface 1042 of the choke seal 1010, and the outer surface 1046 of the piston engages with the inner surface 1042 of the choke seal 1010 thereby controlling, reducing, eliminating, and / or inhibiting fluid flow through the leakage gap 1044. The cap seal 1058, however, may remain trapped by the spacer 1008. From the position illustrated in FIG. 14B, the piston 1006 may further slide in the direction of arrow 1136 to the fully closed position, leaving the cap seal 1058 in the recess 1034 of the spacer 1008. In some embodiments, the first seal portion 1056 does not engage the choke seal 1010 as the piston 1006 is moved in the direction of arrow 1136 to the fully closed position.

[0115] FIG. 14C is a cross-sectional view of the valve seal assembly 1012, in which the piston 1006 of the flow control valve 1000 is in a third position. In some embodiments, the third position is the fully closed position, and the piston 1006 has reached the full stroke length. In the third position, the end of the piston 1006, including the groove 1050, the first seal portion 1056, and the adapter 1060, is disposed on the other side of the choke seal 1010 from the spacer 1008. In the third position of the piston 1006, the piston sealing surface 1048 is engaged with the inner surface 1042 of the choke seal 1010, thereby controlling, reducing, eliminating, and / or inhibiting fluid flow along arrow 1140. Further, in the third position of the piston 1006, the cap seal 1058 is expanded into the radially expanded position within the recess 1034 of the spacer 1008. The first side 1118 of the cap seal 1058 is engaged with the second surface 1104 of the recess, the second side 1120 of the cap seal 1058 is engaged with the piston sealing surface 1048, and the first end 1122 of the cap seal 1058 is engaged with the third surface 1106 of the recess 1034.

[0116] In some embodiments, the interaction between the cap seal 1058, the spacer 1008, and the piston 1006 may aid in controlling, reducing, eliminating, and / or inhibiting fluid flow along arrow 1140. In some embodiments, the interaction between the cap seal 1058, the spacer 1008, and the piston 1006 may not aid in controlling, reducing, eliminating, and / or inhibiting fluid flow along arrow 1140.

[0117] In some embodiments, the first seal portion 1056 may be engaged with the inner surface 1018 of the housing 1002 on the other side of the choke seal 1010. However, in otherembodiments, the first seal portion 1056 may not be engaged with the inner surface 1018 of the housing 1002, but may still be retained in the groove 1050 of the piston 1006 due to the thickness of the first seal portion 1056 and the reduction in flow along arrow 1140.

[0118] The piston 1006 may be moveable from the third position to the first position or other open position, such as the fully open position, in the direction of arrow 1138. As the piston 1006 moves toward the first position, the cap seal 1058 reengages with the first seal portion 1056 such that the cap seal 1058 is compressed into the radially retracted position. In other words, the cap seal 1058 is recaptured within the groove 1050.

[0119] FIG. 14D is a cross-sectional view of the valve seal assembly 1012, in which the piston 1006 of the flow control valve 1000 is in a fourth position (e.g., as the piston 1006 moves toward the first position). As shown, the cap seal 1058 is being partially compressed into the radially retracted position. As the piston 1006 moves in the direction of arrow 1142, the end of the piston 1006, including the groove 1050, slides under and engages the inner surface 1042 of the choke seal 1010 before passing under the choke seal 1010. As the end of the piston 1006 moves in the direction of arrow 1142 toward the first position and past the inner surface 1042 of the choke seal 1010 (e.g. moving from the position of the piston 1006 of FIG. 14C to the position of the piston 1006 in FIG. 14D), the first end 1122 of the cap seal 1058 may engage the second surface 1114 of the groove 1050 to guide the cap seal 1058 in the direction of arrow 1142. As the cap seal 1058 is guided in the direction of arrow 1142, the first side 1118 and / or the second end 1124 of the cap seal 1058 may be guided along the first surface 1102 of the recess 1034 and the profiled portion 1108 of the choke sleeve 1004 to move the cap seal 1058 toward the radially retracted position. However, in some embodiments, electrical or other mechanical components may cause the cap seal 1058 to be guided back into engagement with the inner surface 1020 of the choke sleeve 1004. From the position illustrated in FIG. 14D, the piston 1006 may further slide in the direction of arrow 1142 to the first position after compressing the cap seal 1058 into the radially retracted position.

[0120] FIG. 14E is a cross-sectional view of the valve seal assembly, in which the piston 1006 of the flow control valve 1000 is in the first position. The piston 1006 may move from the fourth position shown in FIG. 14D back into the first position. As such, the position of the piston in FIG.14E is largely the same as the position of the piston described with respect to FIG. 14A. From the first position, the piston 1006 may be moved again toward the fully closed position or may be moved in the opposite direction to selectively open fluid communication between the exterior of the flow control valve 1000 and the interior flow passage 1014 of the flow control valve 1000 via one or more of the choking orifices 1026 of the choke sleeve 1004 to regulate the choke characteristics, manage flow rate, and pressure differentials of the exterior of the flow control valve 1000 and the interior flow passage 1014. The piston 1006 may also be moved repeatedly to and from the fully closed position.

[0121] Any one or more components of the flow control valve 1000 may be integrally formed together, directly coupled together, and / or indirectly coupled together and are not limited to the specific arrangement of components described with reference to FIGS. 13 and 14A-E. Any one or more of the embodiments of the flow control valve 1000 may be combined in whole or part with any one or more of the embodiments of the flow control valve 1000.

[0122] The subject matter described in detail above may be defined by one or more clauses, as set forth below.

[0123] A seal including a seal body, an inner arm protruding from the seal body and configured to engage an inner surface, and an outer arm protruding from the seal body and configured to engage an outer surface. The inner arm includes an inner seal protrusion proximate to a distal end of the inner arm and an inner support protrusion. The outer arm includes an outer seal protrusion proximate to the distal end of the outer arm and an outer support protrusion. The inner seal protrusion and the outer seal protrusion define a seal width. The inner support protrusion and the outer support protrusion define a support width less than the seal width when the seal is in an uncompressed state.

[0124] The seal of the preceding clause, including a coating on at least one of the inner seal protrusion and the outer seal protrusion.

[0125] The seal of any preceding clause, wherein at least one of the inner support protrusion or the outer support protrusion includes a support material that is different from a seal material of at least one of the inner seal protrusion or the outer seal protrusion.

[0126] The seal of any preceding clause, wherein the outer seal protrusion includes a different material from the inner seal protrusion.

[0127] The seal of any preceding clause, wherein the outer support protrusion includes a different material from the outer seal protrusion.

[0128] The seal of any preceding clause, wherein at least one of the inner support protrusion or the outer support protrusion includes a different material from the seal body.

[0129] The seal of any preceding clause, wherein at least one of the inner seal protrusion or outer seal protrusion includes a different material from the seal body.

[0130] The seal of any preceding clause, wherein at least one of the outer support protrusion or the inner support protrusion is non-continuous around a circumference of the seal.

[0131] The seal of any preceding clause, including a second support protrusion distal to the outer seal protrusion on the outer arm.

[0132] The seal of any preceding clause, including a second support protrusion distal to the inner seal protrusion on the inner arm.

[0133] The seal of any preceding clause, wherein at least one of the outer support protrusion or the inner support protrusion has a scraping edge proximate to the seal body.

[0134] A sealing system including a first seal, a first support ring proximate to the first seal and configured to axially support the first seal, a second seal positioned in an axial direction opposite the first seal and across from the first support ring, and a second support ring proximate to the second seal and configured to axially support the second seal between the second seal and the first support ring. The first seal includes a seal body, an inner arm protruding from the seal body and configured to mate with an inner surface, and an outer arm protruding from the seal body and configured to mate with an outer surface. The inner arm includes an inner seal protrusion proximate to a distal end of the inner arm and an inner support protrusion. The outer arm includes an outer seal protrusion proximate to a distal end of the outer arm and an outer support protrusion. The inner seal protrusion and outer seal protrusion define a seal width. The inner support protrusion and the outer support protrusion define a support width.

[0135] The seal system of the preceding clause, wherein the first support ring includes an axial protrusion positioned between the inner arm and outer arm of the first seal.

[0136] The seal system of any preceding clause, including a sealing adaptor between the first support ring and the second support ring.

[0137] The seal system of any preceding clause, including at least one sealing v-ring.

[0138] A method of providing a fluid seal in a downhole environment includes providing an annular seal in contact with a static surface. The method further includes moving a dynamic surface radially opposite to the static surface in an axial direction relative to the annular seal and contacting the dynamic surface with a seal protrusion. The method further includes deforming an arm of the annular seal based at least partially on the contact of the seal protrusion with the dynamic surface, wherein deforming the arm of the annular seal reduces a support pressure of a support protrusion of the annular seal.

[0139] The method of the preceding clause, wherein a seal pressure of the seal protrusion is greater than the support pressure.

[0140] The method of any preceding clause, wherein the support pressure is reduced to zero.

[0141] The method of any preceding clause, including axially centering the dynamic surface relative to the annular seal with the support protrusion.

[0142] The method of any preceding clause, including scraping at least a portion of the dynamic surface with the support protrusion.

[0143] A seal assembly includes a chevron stack of polymeric rings radially between and axially slidably engaged with an inner tube section and an outer tube section, a first spring disposed radially between the inner tube section and the outer tube section, and a second spring disposed radially between the inner tube section and the outer tube section. The chevron stack of polymeric rings includes a first chevron ring, a second chevron ring, and a dual-nosed ring disposed axially between the first chevron ring and the second chevron ring. A first end of the dual-nosed ring engages an end of the first chevron ring and a second end of the dual-nosed ring engages an end of the second chevron ring. The chevron stack of polymeric rings is disposed axially between thefirst spring and the second spring. The first spring and the second spring compress the chevron stack of polymeric rings.

[0144] The seal assembly of the preceding clause, wherein one or more of the first spring and the second spring is a wave spring.

[0145] The seal assembly of any preceding clause, wherein the first spring urges the chevron stack of polymeric rings away from a first retaining ring and toward a second retaining ring.

[0146] The seal assembly of any preceding clause, wherein the first spring is disposed between the chevron stack of polymeric rings and a spacer collar.

[0147] The seal assembly of any preceding clause, wherein a presser ring of the spacer collar abuts the first spring and a support ring of spacer collar aligns the first spring.

[0148] The seal assembly of any preceding clause, wherein the first spring extends beyond the support ring.

[0149] The seal assembly of any preceding clause, wherein the first spring is radially inside the support ring.

[0150] The seal assembly of any preceding clause, wherein the spacer collar is axially slidable relative to the inner tube section and the outer tube section.

[0151] The seal assembly of any preceding clause, wherein a spacer ring is disposed between the first spring and the chevron stack of polymeric rings.

[0152] The seal assembly of any preceding clause, wherein a first retaining ring provides a first hard stop for the first spring and wherein a second retaining ring provides a second hard stop for the second spring.

[0153] The seal assembly of any preceding clause, wherein the first spring urges the polymeric ring toward the second spring and wherein the second spring urges the polymeric ring toward the first spring.

[0154] An axial seal assembly includes a first chevron stack between a first spring and a dualnosed polymeric ring and a second chevron stack between a second spring and the dual-nosed polymeric ring. The first chevron stack includes a first plurality of chevron polymeric rings nested together. The second chevron stack includes a second plurality of chevron polymeric rings nested together. The dual-nosed polymeric ring include a first nose nested into the first chevron stack and a second nose opposite the first nose nested into the second chevron stack.

[0155] The axial seal assembly of the preceding clause, wherein one or more of the first spring and the second spring is a wave spring.

[0156] The axial seal assembly of any preceding clause, wherein the first spring and the second spring axially compress the first chevron stack, the dual-nosed polymeric ring, and the second chevron stack together.

[0157] A seal assembly includes a collar axially between a first spring and a second spring, a first polymeric taper ring engaged with the first spring, a first chevron ring defining a first groove, a second polymeric taper ring engaged with the second spring, and a second chevron ring defining a second groove. A first nose of the first polymeric taper ring nests axially into the first groove. A second nose of the second polymeric taper ring nests axially into the second groove.

[0158] The seal assembly of the preceding clause, wherein one or more of the first spring and the second spring is a wave spring.

[0159] The seal assembly of any preceding clause, wherein the first spring urges the first polymeric taper ring away from the collar and wherein the second spring urges the second polymeric taper ring away from the collar.

[0160] The seal assembly of any preceding clause, wherein a support ring of the collar radially aligns the first spring and the second spring.

[0161] The seal assembly of any preceding clause, wherein a presser ring of the collar extends radially inwardly from the support ring.

[0162] The seal assembly of any preceding clause, wherein the presser ring is located axially medially along the support ring.

[0163] A flow control valve includes a choke sleeve, a spacer including a recess, a choke seal, a piston slidable relative to the choke sleeve and the spacer between a first position and a second position, and a seal assembly. A first end of the spacer is engaged with an end of the choke sleeve. An end of the choke seal is engaged with a second end of the spacer. The piston includes a groove and a seal surface. The seal assembly includes a first seal portion disposed in the groove and a cap seal having a first side and a second side. While the piston is in the first position, the first side of the cap seal is engaged with the choke sleeve and the second side of the cap seal is engaged with the first seal portion. While the piston is in the second position, the first side of the cap seal is engaged with the recess, the second side of the cap seal is engaged with the seal surface of the piston, and the choke seal is disposed between the cap seal and the first seal portion.

[0164] The flow control valve of the preceding clause, wherein the recess includes a surface profile including a tapered portion, the tapered portion tapering to a planar portion of the surface profile.

[0165] The flow control valve of any preceding clause, wherein the spacer and the choke sleeve are integral.

[0166] The flow control valve of any preceding clause, wherein the cap seal includes polyetheretherketone.

[0167] The flow control valve of any preceding clause, wherein the cap seal includes a first end cap, a second end cap, and a body disposed between the first end cap and the second end cap.

[0168] The flow control valve of any preceding clause, wherein the piston includes a first piston sleeve and a second piston sleeve, wherein the groove is defined by an end surface of the first piston sleeve, a first surface of the second piston sleeve, and a second surface of the second piston sleeve.

[0169] The flow control valve of any preceding clause, wherein, while the piston is in the first position, the first seal portion is configured to exert a force onto the second side of the cap seal.

[0170] The flow control valve of any preceding clause, wherein the first seal portion is an O- nng.

[0171] The flow control valve of any preceding clause, wherein the second side of the cap seal includes a tapered surface.

[0172] The flow control valve of any preceding clause, including an adapter disposed in the groove, wherein the adapter abuts the first sealing portion, and wherein the adapter includes a tapered top surface configured to guide the cap seal into the recess when the piston is moved from the first position to the second position.

[0173] A seal assembly includes a cap seal including a body having a first side and second side. The cap seal is compressible from radially expanded position to a radially compressed position. The seal assembly further includes a first seal portion configured to seal against the second side of the cap seal. The first seal portion is configured to bias the cap seal towards the radially expanded position. The cap seal is moveable relative to the first seal portion from a first axial position where the second side is engaged with the first seal portion to a second axial position where the second side is disengaged from the first seal portion.

[0174] The seal assembly of the preceding clause, wherein the cap seal includes a first end cap and a second end cap attached to opposing ends of the body.

[0175] The seal assembly of any preceding clause, wherein the cap seal includes polyetheretherketone.

[0176] A method of controlling fluid flow includes flowing a fluid through an interior passage of a flow control valve while a piston of the flow control valve is in a first position. A seal assembly inhibits fluid flow between the piston and a choke sleeve of the flow control valve while the piston is in the first position. The seal assembly includes a first seal portion and a cap seal. In the first position of the piston, a first side of the cap seal is engaged with a choke sleeve of the flow control valve and a second side of the cap seal is engaged with the first seal portion. Th method further includes sliding the piston from the first position to a second position to expand the cap seal into a recess of a spacer of the flow control valve. The cap seal is disposed between the recess and the first seal portion.

[0177] The method of the preceding clause, wherein expanding the cap seal into the recess includes engaging a first end of the cap seal with a surface of the recess to slide a tapered portion of the second side of the cap seal along a tapered surface of the piston.

[0178] The method of any preceding claim, wherein expanding the cap seal into the recess includes applying a force on the second side of the cap seal with the first seal portion.

[0179] The method of any preceding claim, further including sliding the piston from the second position to a third position to further expand the cap seal and to engage the first side of the cap seal with the recess and to engage the second side of the cap seal with a seal surface of the piston, and to engage the seal surface of the piston with a choke seal of the flow control valve, wherein the choke seal is disposed between the cap seal and the first seal portion.

[0180] The method of any preceding claim, further including sliding the piston from the third position to a fourth position to guide the second side of the cap seal into engagement with the first seal portion.

[0181] The method of any preceding claim, wherein guiding the second side of the cap seal into engagement with the first seal portion includes engaging a first end of the cap seal with a groove surface of the piston to engage a second end of the cap seal with a tapered surface of the recess to guide the second side of the cap seal into engagement with the first seal portion.

[0182] The method of claim 18, further including sliding the piston from the fourth position to the first position.

[0183] Technical effects of the disclosed embodiments include improved sealing of seal assemblies for use within a wellbore. For example, an annular metal seal may include one or more seal protrusions that increase the pressure between the seal and respective surface(s) such that the annular metal seal may produce elastic and / or plastic deformation of the seal protrusion(s) and / or the surface(s) and create a fluid-tight seal. The annular seal may also include one or more support protrusions to reduce deformation of the arms of the annular seal and thereby reduce fatigue on the arms. The support protrusions may also be used to center the annular seal relative to the surface(s). Additionally, various components of the annular seal may be made of different materials. For example, a material of the seal protrusions may be harder than a material of thearms to limit and / or reduce wear on the seal protrusions. The annular seal may also include one or more support protrusions configured to clean a dynamic surface during movement of the dynamic surface. Additionally, the first support protrusion and the second support protrusion may create a zone therebetween in which debris accumulation is blocked and / or reduced to enable the seal protrusions to maintain a fluid seal with the adjacent surface during movement of the dynamic surface.

[0184] As another example, an axial seal assembly may include slidable seal elements to block fluid communication between a first space and a second space. The axial seal assembly also includes springs that apply axial force to the slidable seal elements to produce axial compression in the seal to maintain a tight seal as the slidable seal elements wear, age, experience hot and cold temperature extremes, and / or experience rapid temperature changes.

[0185] As another example, a valve seal assembly may block fluid communication between an exterior and an interior of a flow control valve when a piston of the flow control valve is in a closed position. As such, the valve seal assembly may control, reduce, and / or eliminate fluid and particulate from flowing through a leak path within the flow control valve. The valve seal assembly may include a first seal portion and a cap seal. The cap seal may be configured to move between a recess and a groove as the piston moves from an open position to the closed position and back to better control, reduce, eliminate, or inhibit fluid flow between the piston and other components of the flow control valve. The first seal portion may facilitate moving the cap seal into an expanded position to better seal against leaks while the piston is in the closed position.

[0186] The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. Moreover, the order in which the elements of the methods described herein are illustrated and described may be re-arranged, and / or two or more elements may occur simultaneously. The embodiments were chosen and described in order to best explain the principals of the disclosure and its practical applications, to thereby enable others skilled in the art to best utilize the disclosure and various embodiments with various modifications as are suited to the particular use contemplated.

[0187] The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function]...” or “step for [perform]ing [a function]...”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).

Claims

CLAIMS1. A seal comprising: a seal body; an inner arm protruding from the seal body and configured to engage an inner surface, the inner arm comprising: an inner seal protrusion proximate to a distal end of the inner arm, and an inner support protrusion; and an outer arm protruding from the seal body and configured to engage an outer surface, the outer arm comprising: an outer seal protrusion proximate to a distal end of the outer arm; and an outer support protrusion; wherein the inner seal protrusion and the outer seal protrusion define a seal width, and the inner support protrusion and the outer support protrusion define a support width less than the seal width while the seal is in an uncompressed state.

2. The seal of claim 1, wherein at least one of the inner support protrusion or the outer support protrusion includes a support material that is different from a seal material of at least one of the inner seal protrusion or the outer seal protrusion.

3. The seal of claim 1, wherein at least one of the inner support protrusion or the outer support protrusion includes a different material from the seal body.

4. The seal of claim 1, wherein at least one of the outer support protrusion or the inner support protrusion is non-continuous around a circumference of the seal.

5. The seal of claim 1, further comprising: a second outer support protrusion distal to the outer seal protrusion on the outer arm; and a second inner support protrusion distal to the inner seal protrusion on the inner arm.

6. The seal of claim 1, wherein at least one of the outer support protrusion or the inner support protrusion has a scraping edge proximate to the seal body.

7. A seal assembly, comprising: a chevron stack of polymeric rings disposed radially between and axially slidably engaged with an inner tube section and an outer tube section, the chevron stack of polymeric rings comprising: a first chevron ring; a second chevron ring; and a dual-nosed ring disposed axially between the first chevron ring and the second chevron ring, wherein a first end of the dual-nosed ring engages an end of the first chevron ring, and a second end of the dual-nosed ring engages an end of the second chevron ring; a first spring disposed radially between the inner tube section and the outer tube section; and a second spring disposed radially between the inner tube section and the outer tube section, the chevron stack of polymeric rings being disposed axially between the first spring and the second spring, and the first spring and the second spring axially compressing the chevron stack of polymeric rings.

8. The seal assembly of claim 7, wherein one or more of the first spring or the second spring is a wave spring.

9. The seal assembly of claim 7, wherein the first spring is disposed between the chevron stack of polymeric rings and a spacer collar.

10. The seal assembly of claim 9, wherein a presser ring of the spacer collar abuts the first spring and a support ring of the spacer collar aligns the first spring.

11. The seal assembly of claim 10, wherein the first spring extends beyond the support ring.

12. The seal assembly of claim 7, wherein a spacer ring is disposed between the first spring and the chevron stack of polymeric rings.

13. The seal assembly of claim 7, wherein the first spring urges the chevron stack of polymeric rings away from a first retaining ring and toward a second retaining ring.

14. A flow control valve comprising: a choke sleeve; a spacer including a recess, wherein a first end of the spacer is engaged with an end of the choke sleeve; a choke seal, wherein an end of the choke seal is engaged with a second end of the spacer; a piston slidable relative to the choke sleeve and the spacer between a first position and a second position, wherein the piston includes a groove and a seal surface; and a seal assembly, including: a first seal portion disposed in the groove; and a cap seal having a first side and a second side, wherein: while the piston is in the first position, the first side of the cap seal is engaged with the choke sleeve and the second side of the cap seal is engaged with the first seal portion; and while the piston is in the second position, the first side of the cap seal is engaged with the recess, the second side of the cap seal is engaged with the seal surface of the piston, and the choke seal is disposed between the cap seal and the first seal portion.

15. The flow control valve of claim 14, wherein the cap seal comprises polyetheretherketone.

16. The flow control valve of claim 14, wherein the cap seal includes: a first end cap; a second end cap; and a body disposed between the first end cap and the second end cap.

17. The flow control valve of claim 14, wherein the first seal portion is an O-ring.

18. The flow control valve of claim 14, wherein, while the piston is in the first position, the first seal portion is configured to exert a force onto the second side of the cap seal.

19. The flow control valve of claim 14, wherein the second side of the cap seal includes a tapered surface.

20. The flow control valve of claim 14, further comprising an adapter disposed in the groove, wherein the adapter abuts the first sealing portion, and wherein the adapter includes a tapered surface configured to guide the cap seal into the recess when the piston is moved from the first position to the second position.

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