US20060186601A1

US20060186601A1 - Fluid seals

Info

Publication number: US20060186601A1
Application number: US11/061,460
Authority: US
Inventors: Jean-Marc Lopez
Original assignee: Halliburton Energy Services Inc
Current assignee: Halliburton Energy Services Inc
Priority date: 2005-02-18
Filing date: 2005-02-18
Publication date: 2006-08-24
Also published as: CA2536616A1

Abstract

Certain embodiments of the invention are directed to a sealing device having greater resistance to failure when exposed to elevated temperature or pressure conditions. A number of embodiments of the invention include a sealing device having an annular seal member comprising an elastomer material and at least one cap member affixed to the seal member. In some circumstances, when the seal member is compressed in a substantially axial direction, at least a portion of the cap member deforms in a substantially radial direction.

Description

TECHNICAL FIELD

This invention relates to seals that restrict or otherwise control fluid flow.

BACKGROUND

Sealing devices, such as o-rings and the like, may be used to form a fluid seal between two mating parts. For example, when a metallic cylindrical plug is inserted into a metallic tubular member to restrict fluid flow, an o-ring seal may be positioned in a circumferential groove formed in the plug. The o-ring may have an outer diameter that is larger than both the inner diameter of the tubular member and the outer diameter of the plug. In such circumstances, when the plug is inserted into the tubular member, the o-ring is compressed between the outer circumferential surface of the plug and the inner circumferential surface of the tubular member. If fluid seeps in the clearance space between the plug and the tubular member, the o-ring may form an effective seal that prevents fluid flow through the clearance space past the plug.
In the event of seal failure, fluid leakage may occur—requiring replacement of the sealing device or, in some circumstances, rendering the associated machinery inoperable. The time and costs required to repair or replace the inoperable machinery can be significant. For example, accessing fluid control machinery disposed in underground wells is a time-consuming and laborious task. If such machinery is rendered inoperable by the failure of a sealing device, considerable time and costs must be spent in order to retrieve, repair, and restore the machinery. Throughout the entire process, production from the well may be completely shutdown until the machinery is restored.
The material of the seal is one design factor that affects seal failure. For example, if a seal is exposed to sufficiently high pressures so as to overcome the seal material's strength, the seal may be extruded through the clearance space between the mating parts. Also, if the seal is exposed to sufficiently high temperatures, the seal material may deteriorate, thereby permitting fluid to flow past the seal location.
The geometry of the seal is another design factor that affects seal failure. If the seal is improperly sized for the groove in which it sits, fluid may seep past the seal in the groove. Also, if the radial clearance between the mating parts is relatively large compared to the radial height of the seal, the seal may be at least partially “blown out” (forced out its groove and into the clearance space between the mating parts), thereby permitting fluid to leak through the seal location.

SUMMARY

Certain embodiments of the invention are directed to a sealing device having greater resistance to failure when exposed to elevated temperature or pressure conditions.
A number of embodiments of the invention include a sealing device. The seal device may include an annular seal member comprising an elastomer material. The annular seal member may be disposed radially from an axis and may have a first seal surface exposed on an outer radial side and a second seal surface exposed on an inner radial side. The seal device may further include a cap member affixed to an axial side of the seal member. The cap member may be disposed radially between the first and second seal surfaces, and the cap member may be formed of material having substantially greater strength than the elastomer material of the seal member. In such embodiments, when the seal member is compressed in a substantially axial direction that is substantially parallel to the axis, at least a portion of the cap member deforms in a substantially radial direction.
In some embodiments, a device includes a first body, a second body having a groove, and a seal in the groove. The seal may be adapted to substantially seal between the first and second bodies. The seal may include an annular seal member having a first substantially convex surface and a second substantially convex surface. The seal may further include a first cap member having a first substantially concave surface affixed to the first substantially convex surface of the seal member such that deformable portions of the first cap member are positioned radially on both sides of a portion of the seal member. Also, the seal may include a second cap member having a second substantially concave surface affixed to the second substantially convex surface of the seal member such that deformable portions of the second cap member are positioned radially on both sides of a portion of the seal member.
In another embodiment, a method of sealing between a first body and a second body includes providing a seal device in a groove of the second body. The seal device may have an elastomeric seal member defining a first seal surface to press against the first body and a second seal surface to press against the second body. The seal device may also have a cap member affixed to an axial side of the seal member and disposed radially between the first and second seal surfaces. The method further includes, in response to pressure applied to the seal between the first and second seal surfaces, deforming the cap member to press against the first and second bodies.
These and other embodiments may be configured to provide one or more of the following advantages. First, even when the sealing device is exposed to elevated temperature or pressures, the sealing device may be configured to reduce the likelihood of extrusion through the clearance space between the mating parts. Second, the sealing device may have increased radial strength while maintaining some degree of flexibility. Third, the sealing device may be configured to reduce the likelihood of seal “blow out” or other types of seal failure. Fourth, large quantities of the sealing device may be cost-effectively manufactured using molding techniques. Some or all of these and other advantages may be provided by the devices and methods described herein.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a sealing device in accordance with an embodiment of the invention.
FIG. 2A is a cross-sectional view of the sealing device of FIG. 1.
FIG. 2B is an exploded view of the sealing device of FIG. 2A.
FIG. 2C is a cross-sectional view of a sealing device in accordance with another embodiment of the invention.
FIGS. 3A-B are cross-sectional views of a sealing device disposed in a groove in accordance with an embodiment of the invention.
FIGS. 4A-C are cross-section views of a sealing device disposed in a groove in accordance with another embodiment of the invention.
FIGS. 5A-B are views of a packer system having the seal device of a FIG. 1, in accordance with some embodiments of the invention.
Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

Referring to FIG. 1, a sealing device 100 may include a seal member 120 and one or more cap members 140 and 160. In a number of embodiments, the sealing device 100 may be inserted into a groove or otherwise positioned between two contact surfaces so as to control fluid flow between the surfaces. The sealing member 120 may have a shape that is generally similar the shape of the groove or contact surfaces. In the embodiment shown in FIG. 1, the sealing device 100 has a generally annular shape that is disposed radially about a central axis 110. The cap members 140 and 160 are coupled to opposing axial sides of the seal member 120. As such, the cap members 140 and 160 comprise at least a substantial portion of the faces 104 and 106 of the device 100. The inner exposed surface 126 and the outer exposed surface 128 of the sealing member 120 are exposed along the inner circumferential side 102 and the outer circumferential side 108 of the device 100. In these embodiments, the sealing member 120 and the cap members 140 and 160 collectively form at least a substantial portion of the inner and outer circumferential sides 102 and 108 of the device 100.
Referring to FIGS. 2A-B, the cap members 140 and 160 may include mating surfaces that join with complementary surfaces on the sealing member 120. In this embodiment, the cap member 140 mates with the sealing member 120 such that extension portions 144 and 146 are disposed radially on both sides of portions of the sealing member 120. For example, the cap member 140 may have a mating surface 142 at least a portion of which includes a concave curvature. The sealing member 120 has a mating surface 122 that is joined to the mating surface 142 of the cap member 140. At least a portion of the sealing member's mating surface 122 has a convex curvature that substantially complements the cap member's mating surface 142. As such, the extension portions 144 and 146 are disposed radially on both sides of portions of the sealing member 120.
As shown in FIGS. 2A-B, the second cap member 160 may have a similar size and shape as the first cap member 140. In the depicted embodiment, the second cap member 160 has a mating surface 162 that joins a mating surface 124 of the sealing member 120 on an axial side opposite the first cap member 140. Again, the cap member 160 may mate with the sealing member 120 such that extension portions 164 and 166 are disposed radially on both sides of portions of the sealing member 120. At least a portion of the second cap member's mating surface 162 may have a concave curvature, which is substantially complementary to a convex curvature on the sealing member's mating surface 124.
Still referring to embodiment shown in FIGS. 2A-B, the cap member 140 may be disposed radially between the inner exposed surface 128 and an outer exposed surface 128 of the seal member 120. As such, the exposed surfaces 126 and 128 of the seal member 120 are capable of pressing against inner and outer bodies to form a seal (described in form detail below in connection with FIGS. 3A-B). In such circumstances, the device 100 may use the exposed surfaces 126 and 128 of the seal member 120 to form a seal between two bodies while the cap members 140 and 160 may enhance the seal performance.
The cap member 140 may include an inner circumferential surface 148 and an outer circumferential surface 149. The inner circumferential surface 148 faces in a generally radial direction and forms a portion of the device's inner circumferential side 102. The outer circumferential surface 149 faces in a generally radial direction opposite that of the inner circumferential surface 148 (but not necessarily exactly opposite and parallel of the inner circumferential surface 148). The cap 140 may have an axial-facing surface 150 that forms a substantial portion of the sealing device's face 104. In some embodiments, the inner and outer circumferential surfaces 148 and 149 may be tapered at angles 152 and 154 toward to the axial-facing side 150 to compensate for thermal expansion. As shown in FIG. 2B, for example, the circumferential surfaces 148 and 149 are tapered at an angle of about 1 degree to about 10 degrees—preferably about 4 degrees. The tapering angles 152 and 154 of the circumferential surfaces 148 and 149 may vary depending on the thermal expansion of the cap member material and the desired flow characteristics during operation. In the embodiment depicted in FIGS. 2A-B, the cap member 140 has beveled surfaces between the axial-facing side 150 and the circumferential surfaces 148 and 149.
As previously described, the second cap member 160 may have a similar size and shape as the first cap member 140. In such embodiments, the second cap member 160 may have an inner circumferential surface 168 and an outer circumferential surface 169 similar to those of the first cap member 140. Also, the second cap member 160 may have a surface 170 that generally faces an opposite axial direction from the axial-facing side 150 of the first cap member 140. In some embodiments, the inner and outer circumferential surfaces 168 and 169 may be tapered at angles 172 and 174 toward to the axial-facing side 170 of the second cap member 160. The tapering angles 172 and 174 of the circumferential surfaces 168 and 169 may vary depending on the thermal expansion of the cap member material and the desired flow characteristics. Furthermore, the second cap member 160 may have beveled surfaces between the axial-facing surface 170 and the circumferential surfaces 168 and 169.
The sealing device 100 may be manufactured using a number of processes and various materials. Referring now to FIG. 2B, the cap members 140 and 160 may be formed of a different material from the sealing member 120 and bonded to the sealing member 120. The cap members 140 and 160 may comprise a polymer material that is capable of a substantially elastically deforming when pressure is applied to the sealing device 100 (described in more detail below). The type of polymer material for the cap members 140 and 160 may vary depending on the application of the sealing device 100, the flow temperature and pressure characteristics, the possibility of corrosion, and other factors. For example, the cap members 140 and 160 may comprise Polyetheretherketone (PEEK), Polyetherimide (PEI), Torlon™, Teflon™, other thermoplastic polymers, rubber materials having a relatively high degree of hardness, rubber or thermoplastic materials having reinforcing fibers (such as glass fibers) embedded therein, or the like. In some circumstances, the cap members 140 and 160 may be thermoformed to the desired shape, and if necessary, certain machining operations may be performed on the thermoformed parts.
The sealing member 120 may comprise an elastomer material that has a sufficiently high operating temperature capabilities and desired elasticity properties. The type of elastomer material for the sealing member may vary depending on the application of the sealing device 100, the flow temperature and pressure characteristics, and other factors. For example the sealing member 120 may comprise Hydrogenated Nitrile Butadiene Rubber (HNBR) or other Nitrile Butadiene Rubbers, C. R. Chloroprene Rubber, Polyisoprene, Styrene Butadiene Rubber (SBR), Isoprene-Isobutylene Rubber (IIR), Chlorinated Butyl (Chlorobutyl), Polyacrylic, Epichlorohydrin (Hydrin™), Thiokol Polysulfide, Silicone and Fluoro-Silicone Rubber, Hypalon™, Fluoro Elastomers (e.g., Viton™ or Fluorel™), Polybutadiene, Ethylene Propylene Copolymer (ERM), Ethylene Propylene Diene Terpolymer (ERDM), TFE Propylene (Aflas™), or other like materials. In some circumstances, the sealing member 120 may comprise an elastomer material having reinforcing fibers of a different material (such as glass fibers) embedded therein.
In some embodiments, the material of the cap members 140 and 160 is selected such that the cap member material has substantially greater strength that the elastomer material of the seal member 120. In addition, the cap member material may be selected to have a greater resistance to degradation from temperature than the elastomer material of the seal member. In one illustrative example, the cap members 140 and 160 may comprise a PEEK material, and the seal member 120 may comprise a HNBR material. In this example, the PEEK material is substantially stronger than the HNBR so as to provide supplemental radial strength to the overall device 100. Also in this example, the PEEK material is capable of operating a higher temperatures than the HNBR material, which may may permit the device 100 to maintain a seal at temperatures greater than the normal operating temperature of the HNBR material by itself (described in more detail below).
Still referring to FIG. 2B, a bonding agent may be applied to the mating surfaces 142 and 162 of the cap members 140 and 160. The bonding agent may be an adhesive that affixes the complementary surfaces to one another. Alternatively, the bonding agent may be a chemical agent that promotes bonding between the materials during the in-molding process that forms the seal member 120. The cap members 140 and 160 are attached to the seal member 120 such that, when the seal member 120 is compressed in an axial direction (e.g., a direction substantially parallel to the central axis 110), certain portions of the cap members 140 and 160 may flex or otherwise deform in a substantially radial direction (described in more detain below).
In some embodiments, the sealing member may be manufactured using an in-molding process. In such circumstances, the cap members 140 and 160 may be thermoformed from a polymer material, as previously described. Then the first cap member 140 is positioned in a first mold half, and the second cap member 160 is disposed in a second mold half. The mold halves include spaces to receive the cap members 140 and 160 and other geometries that define the shape of the seal member 120. The mold halves are pressed together such that the cap members 140 and 160 are disposed substantially parallel to one another with the mating surfaces 142 and 162 facing one another. Preferably, a bonding agent is applied to the mating surfaces 142 and 162 of the cap members 140 and 160 so as to promote bonding between the seal member material and the cap members 140 and 160. When the mold halves are properly positioned, the elastomer material is injected into the space between the cap members 140 and 160. The in-molding process continues until the seal member 120 is formed (e.g., thermoset, thermoformed, or the like) to the desired shape between the cap members 140 and 160.
It should be understood that the sealing device may be formed to include geometries other than those shown in FIGS. 2A-B. For example, alternative cap members 240 and 260 are shown in FIG. 2C. The alternative cap members 240 and 260 may include notches 245 and 265 in the mating surfaces 242 and 262, respectively. The notches 245 and 265 may enhance the flexing motion of the extension portions 244 and 246 of cap members 240 and 260. Furthermore, the notches 245 and 265 may increase the surface area between the cap member material and the seal member material, which in turn may improve the bonding between the sealing member 220 and the cap members 240 and 260. Such improved bonding may be more significant when the seal member 220 is formed using an in-molding process, as described above. The sealing member 220 may also include tongue portions 225 that extend into the notches 245 and 265.
Still referring to FIG. 2C, the mating surfaces 242 and 262 of the alternative cap members 240 and 260 do not necessarily include a concave curvature. Each cap member 240 and 260 may include a V-shaped groove with substantially straight and inwardly angled surfaces 242 and 262. The sealing member 220 may include mating surfaces 222 and 224 that have a shape complementary to the corresponding mating surfaces 242 and 262. As previously described, the cap member 240 mates with the sealing member 220 such that extension portions 244 and 246 are disposed radially on both sides of portions of the sealing member 220. Similarly, the second cap member 260 mates with the sealing member 220 such that extension portions 264 and 266 are disposed radially on both sides of portions of the sealing member 220.
In operation, the sealing device may form an effective seal between two contact surfaces with improved resistance to seal failure. The sealing device may be configured to reduce the likelihood of extrusion through the clearance space between the mating parts, even when the sealing device is exposed to elevated temperature or pressures. Furthermore, some embodiments the sealing device may operate as a dynamic seal while reducing the likelihood of seal “blow out.”
Referring to FIGS. 3A-B, the sealing device 100 may be disposed in a groove 310 to provide a seal in the clearance space 305 between two contact surfaces 300 and 302. When the fluid pressure causes the seal member 120 to be compressed in a substantially axial direction, portions of the cap members 140 and 160 may be flexed or otherwise deformed in a substantially radial direction to further enhance the performance of the seal. In these cases, the fluid pressure acting upon the sealing device 100 may be used to enhance seal performance, thereby reducing the likelihood of seal failure under elevated pressures. In some embodiments, the sealing device 100 may be capable of providing a fluid seal under temperatures and pressure that would ordinarily cause an traditional rubber o-ring to deteriorate and extrude through the clearance space 305.
Referring now to FIG. 3A, in this embodiment the sealing device 100 is sufficiently sized such that the sealing member 120 abuts both the circumferential surface 312 of the groove 310 and the first contact surface 300 (e.g., the outside diameter surface of the inner body). As previously explained, the cap members 140 and 160 may have circumferential surfaces 148, 149 and 168, 169 that are tapered. In such embodiments, the sealing device 100 may be sized such that the tips 158, 159 and 178, 179 of the cap members 140 and 160 abut the same surfaces as the sealing member 120. Under these circumstances, the sealing member 120 and the cap members 140 and 160 are pressed against the surfaces 300 and 312, which may provide a fluid seal in the clearance space 305.
Referring to FIG. 3B, the seal performance may be enhanced when greater fluid pressure (e.g., compared to the fluid pressure exhibited in FIG. 3A) is applied to the sealing device 100. When the fluid pressure is acting upon the sealing device 100 in a substantially axial direction 10, the first cap member 140 is forced toward the second cap member 160, which is retained by at least one wall of the groove 310. If the fluid pressure is sufficient to compress the sealing device 100 in the substantially axial direction 10, the elastomer material of the sealing member 120 deforms, which in turn forces portions of the polymer cap members 140 and 160 to deform in a substantially radial direction 20. In this embodiment, at least the extension portions 144, 146 and 164, 166 (e.g., the portions of the cap members 140 and 160 that are disposed radially of both sides of portions of the seal member 120) deform in the substantially radial direction 20. Such deformation of the cap members 140 and 160 causes the circumferential sides 148, 149 and 168, 169 to forcefully press against the circumferential surfaces 300 and 312 and tightly close off any extrusion path through which the sealing member 120 can extrude. Furthermore, the convex shape of the mating surface 142, 162 increases the force in which the circumferential sides 148, 149 and 168, 169 press against the circumferential surfaces 300 and 312 as the pressure applied to the sealing device 100 increases. As shown in FIG. 3B, a greater proportion of the cap members' circumferential sides 148, 149 and 168, 169 may contact the circumferential surfaces 300 and 312 when the fluid pressure causes the compression of the sealing device 100. In this manner, the cap members 140 and 160 reduce the tendency of the sealing member 120 to extrude at high pressures and/or temperatures, and enable the sealing device 100 to seal a gap 305 that is larger than could be sealed without the cap members 140, 160.
In some embodiments, the sealing device 100 may be capable of providing a fluid seal under temperatures and pressure that would ordinarily cause a traditional rubber o-ring or even the sealing member 120 itself (i.e. without cap members 140, 160) to deteriorate and extrude through the clearance space 305. In such embodiments, the material of the cap members 140 and 160 may have a greater resistance to degradation from temperature than the elastomer material of the seal member 120. For example, in one application a sealing device 100 comprising cap members 140 and 160 formed of PEEK thermoplastic material and a sealing member 120 formed of HNBR elastomer material is capable providing a fluid seal when exposed to fluid at 15,000 psi and 350° F. In general, the HNBR elastomer material may break down at temperatures of about 350° F., so in the same application, a traditional o-ring or the sealing member 120 alone made of the HNBR material would likely be extruded through the clearance space 305 when exposed to fluid at 15,000 psi and 350° F. It is believed that the polymer cap members 140 and 160 forcefully press against the circumferential surfaces 300 and 312 to retain the elastomer material of the sealing member 120 when the device 100 is exposed to fluid at 15,000 psi and 350° F., thus preventing or reducing the likelihood of extrusion of the elastomer material through the clearance space 305.
Referring now to FIGS. 4A-C, the sealing device 100 may operate as a dynamic seal to control fluid flow and may have a design that reduces the likelihood of seal “blow out.” For example, the sealing device 100 may permit fluid to flow past the seal location when a contact surface is a first position and may provide a fluid seal when the contact surface is moved to a second position relative to the seal location. As previously described, the energy from the fluid pressure may be used to advantageously deform the sealing device 100 to enhance the seal performance.
Referring to FIG. 4A, the sealing device 100 is disposed between an inner body 400 and an outer body 401 in a groove 410 such that fluid is permitted to flow through the clearance space 405. In this embodiment, the inner body 400 and the outer body 401 are designed to move relative to one another so as to control the fluid flow. When the first contact surface 402 is positioned as shown in FIG. 4A, the sealing member 120 does not necessarily press against both the circumferential surface 412 of the groove 410 and the first contact surface 402, so fluid flow is restricted but not necessarily sealed. (Alternatively, the sealing device 100 may be sized so that the sealing member 120 contacts both the circumferential surface 412 of the groove 410 and the first contact surface 402 of the inner body 400. However, the sealing member 120 may not press against the circumferential surfaces 402 and 412 with sufficient force so as to form a fluid-tight seal. In such circumstances, some fluid may flow past the seal device 100.) The fluid flow may be subsequently sealed when the chamfer 403 and the second contact surface 404 are shifted so as to contact the seal device 100, as described in more detail below.
Referring now to FIG. 4B, when the inner body 400 is shifted in a substantially axial direction so that the chamfer 403 first begins to contact the sealing member 120 of the sealing device 100, the fluid flow becomes restricted between the chamfer 402 and the sealing member 120. However, during this stage it is possible that fluid may flow past the sealing device 100 along the groove surface 412, resulting in a relatively higher pressure radially outside of the sealing device 100 than radially inside the sealing device 100 until the area between the sealing device 100 and surface 402 is filled with fluid. In such circumstances, some traditional o-rings would be susceptible to being “blown out” (forced out its groove and into the clearance space between the inner and outer bodies) due the resulting pressure differential caused by the fluid flow along the groove surface 412 and lack of (or substantially reduced) flow between the sealing member 120 and the chamfer 403.
The embodiment of the sealing device 100 shown in FIG. 4B reduces the likelihood of such seal “blow outs.” When the chamfer 403 contacts the sealing device, the sealing device 100 may be shifted in a substantially radial direction, which in turn causes portions of the cap members 140 and 160 to press against the circumferential surface 412. When the cap members 140 and 160 are pressed against the surface 412, the fluid flow along the groove surface 412 may be substantially reduced. The reduced flow is less likely to force the sealing device 100 out of the groove 410 and reduces the likelihood of seal “blow out.” Furthermore, one or both of the cap members 140, 160 may comprise a polymer material that is substantially more rigid than the elastomer material of the sealing member 120. In these embodiments, the cap members 140, 160 increase the radial rigidity of the sealing device 100 and make the sealing device 100 less likely to be flexed into a position that can squeezed into the clearance space 405 (i.e. the initial stages of a “blow out” may be less likely to occur).
Referring to FIG. 4C, the inner body 400 may be shifted further in the substantially axial direction such that the second contact surface 404 is adjacent the first cap member 140 and the sealing member 120. The first cap member 140 may comprise a polymer material that is capable of substantially elastically deforming when the second contact surface 404 is shifted to decrease the space in the groove 410. In some circumstances, the cap member's polymer material may be advantageous (compared to non-deformable materials) because it can be sized to fit snugly in the space between the first contact surface 402 and the groove surface 412 and then be substantially elastically deformed to fit in the decreased space between the second contact surface 404 and the groove surface 412. Similarly, the second cap member 160 may comprise a polymer material that is capable of substantially elastically deforming when the second contact surface 404 is fully shifted so as to abut the second cap member 160.
When the chamfer 403 and the second contact surface 404 are shifted toward the second cap member 160, the fluid pressure may cause the sealing device 100 to be compressed in a substantially axial direction. As shown in FIG. 4C, the first cap member 140 is forced toward the second cap member 160, which is retained by at least one wall of the groove 410. If the fluid pressure is sufficient to compress the sealing device 100 in the substantially axial direction 10, the elastomer material of the sealing member 120 deforms, which in turn forces portions of the polymer cap members 140 and 160 to deform in a substantially radial direction. In this embodiment, at least the extension portions 144, 146 and 164, 166 deform in the substantially radial direction. Such deformation of the cap members 140 and 160 causes the cap members' circumferential sides 148, 149 and 168, 169 to press against the contact surfaces 402, 404 and the groove surface 412, which may provide a fluid-tight seal. Comparing FIG. 4C to the previously described FIG. 4A, a greater proportion of the cap members' circumferential sides 148, 149 and 168, 169 may contact the contact surfaces 402, 404 and the groove surface 412 when the fluid pressure causes the compression of the sealing device 100. Accordingly, the energy from the fluid pressure and temperature may be used to advantageously deform the sealing device 100 to enhance the seal performance.
Referring to FIGS. 5A-B, the previously described embodiments of the sealing device may provide an effective fluid seal when exposed to elevated pressures and temperatures, such as those conditions present in some fluid control machinery disposed in underground wells. One example of a fluid control system disposed in underground wells is known as a packer 500. One purpose of the packer 500 is to seal the annulus 515 between the outside of the production tubing 520 and the inside of the well casing 510 so as to block movement of fluids through the annulus 515 past the packer location. As shown in FIG. 5A, the packer 500 is releasably engaged with the bore of the well casing 510. The tubular well casing 510 lines a well bore which has been drilled through, for example, an oil producing formation. The packer 500 is connected to the production tubing 520, which may lead to a wellhead for conducting produced fluids to the surface.
Referring now to FIG. 5A, the packer 500 is releasably set and locked against the casing 510 by one or more anchor slip assemblies 530. The anchor slip assemblies 530 may have opposed camming surfaces that cooperate with complementary opposed wedging surfaces 535. In such embodiments, the anchor slip assemblies 530 are radially extendible into gripping engagement against the well casing 510 in response to relative axial movement of the wedging surfaces 535. In general, the anchor slip assemblies 530 are first set against the well casing 510, and further axially compress a seal element assembly 550 causing the seal element assembly 550 to expand radially. The seal element assembly 550 can be expanded against the well casing 510 to provide a fluid-tight seal between the packer mandrel and the well casing 510. As such, pressure is held in the well bore below the seal element assembly 550.
Referring now to FIG. 5B. the seal element assembly 550 of the packer 500 may include the sealing device 100 described in connection with FIGS. 1-4. In this embodiment, the sealing device 100 includes a sealing member 120 and cap members 140 and 160 affixed to opposing axial sides of the sealing member 120. The sealing device 100 is capable of providing a substantially fluid-tight seal such that fluid between the inner body 551 and the outer body 552 is restricted from flowing from the first clearance space 561 to the second clearance space 565, or vice versa. In some circumstances, the seal device may be exposed to and seal against fluid at pressures in excess of 15,000 psi and at temperatures greater than 350° F.
The sealing device 100 in the packer 500 may operate similar to the embodiment shown in FIGS. 4A-C. The sealing device 100 may be disposed in a groove 560 similar to that of groove 410. When the inner body 551 is in the position shown in FIG. 5B, the fluid may be permitted to seep past the sealing device 100 similar to the process described in connection with FIG. 4A. When the inner body 551 is shifted relative to the outer body 552 such that the chamfer 563 is in contact with the first cap member 140, the fluid flow is restricted and the fluid pressure increases. As previously described, the sealing device 100 is design to resist “blow outs” and other seal failures even at the increased pressure levels. A fluid-tight seal may be formed when the inner body 551 is shifted so that the second contact surface 564 abuts the at least the first cap member 140 and the sealing member 120. (In some instances, the second contact surface 564 is shifted so as to contact both cap members 140 and 160.) As previously described in connection with FIG. 4C, when the fluid pressure causes the sealing device 100 to be compressed in a substantially axial direction, the cap members 140 and 160 deform in a substantially radial direction. Such deformation of the cap members 140 and 160 causes the cap members' circumferential sides to press against the contact surface 564 (or both 564 and 562) and the circumferential surface of the groove 560, which may provide a fluid-tight seal. In such circumstances, the energy from the fluid pressure may be used to advantageously deform the sealing device 100 to enhance the seal performance in the packer 500.
Still referring to FIG. 5B, in a presently preferred embodiment, the sealing device 100 comprises cap members 140 and 160 formed of PEEK thermoplastic material and a sealing member 120 formed of HNBR material. Such an embodiment is capable of providing a fluid seal in a packer 500 when the fluid has a pressure of 15,000 psi and a temperature of 350°, conditions that may be generally too extreme for traditional single-material, rubber seals. The sealing device 100 may form an effective seal in the packer 500 with improved resistance to seal failure. Even when the sealing device 100 is exposed to a pressure of 15,000 psi and a temperature of 350° F., the sealing device 100 performs with a reduced likelihood of extrusion through the clearance space 565. Furthermore, the sealing device 100 may operate as a dynamic seal with a reduced likelihood of seal “blow out” when the chamfer 563 approaches the seal location.
It is not necessary that the sealing device 100 include two cap members 140, 160. In some embodiments, the sealing device may include the sealing member 120 and a single cap member 160. In such embodiments, the energy from the fluid pressure and temperature may be used to advantageously deform the sealing device to enhance the seal performance.
One such embodiment is shown in FIGS. 6A-B. A sealing device 600 may include an seal member 620 and a cap member 660. The cap member 660 may comprise a thermoplastic polymer material that is substantially stronger than the elastomer material of the seal member 620. In addition, the cap member 660 may comprise a material that has greater resistance to degradation from temperature than the elastomer material of the seal member 620. Similar to the process described above in connection with FIGS. 3A-B, when the fluid pressure causes the sealing device 600 to be compressed in a substantially axial direction, the elastomer material of the sealing member 620 deforms, which in turn forces portions of the cap member 660 to deform in a substantially radial direction. Such deformation of the cap member 660 causes the cap member's circumferential sides 668 and 669 to press against the contact surface 602 and the circumferential surface 612 of the groove 610, which may provide a fluid-tight seal.
In such circumstances, the energy from the fluid pressure may be used to advantageously deform the sealing device 600 to enhance the seal performance. Furthermore, the cap member 660 may provide increased radial strength to the sealing device 600 while maintaining a substantial degree of elasticity and flexibility of the overall sealing device. The sealing device 600 may form an effective seal between two bodies with improved resistance to seal failure. Even when the sealing device is exposed to elevated temperature or pressures, the sealing device 600 may be configured to reduce the likelihood of extrusion through the clearance space 605 between the mating bodies. Furthermore, the cap member 660 of the sealing device 600 may operate reduce the likelihood of seal “blow out,” as previously described.
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.

Claims

1. A sealing device comprising:

an annular seal member comprising an elastomer material, the annular seal having a first seal surface exposed on a first side and a second seal surface exposed on an inner second side; and

a cap member affixed between the first and second seal surfaces of the seal member, the cap member formed of material having substantially greater strength than the elastomer material of the seal member,

wherein when pressure is applied between the seal surfaces, the seal member is compressed in a certain direction substantially toward the cap member and causes at least a portion of the cap member to deform substantially perpendicular to the certain direction.

2. The sealing device of claim 1, further comprising a second cap member affixed to the seal member opposite the first mentioned cap member and disposed between the first and second seal surfaces, at least a portion of the second cap member operable to deform substantially perpendicular to the certain direction when the seal member is compressed in the certain direction.

3. The sealing device of claim 1, wherein the cap member comprises a thermoplastic material.

4. The sealing device of claim 1, wherein the cap member comprises a material having a greater resistance to degradation from temperature than the elastomer material of the seal member.

5. The sealing device of claim 1, wherein the cap member comprises a material selected from the group consisting of: Polyetheretherketone, Polyetherimide, Torlon™, and Teflon™.

6. The sealing device of claim 1, wherein the seal member comprises a material selected from the group consisting of: Hydrogenated Nitrile Butadiene Rubber, Nitrile Butadiene Rubber, Chloroprene Rubber, Polyisoprene, Styrene Butadiene Rubber, Isoprene-Isobutylene Rubber, Chlorinated Butyl, Polyacrylic, Epichlorohydrin, Thiokol Polysulfide, Silicone and Fluoro-Silicone Rubber, Hypalon™, Fluoro Elastomer, Polybutadiene, Ethylene Propylene Copolymer, Ethylene Propylene Diene Terpolymer, and TFE Propylene.

7. The sealing device of claim 1, wherein when the seal member is disposed between an outer body and an inner body, the cap member is affixed to the side of the seal member proximal to a clearance space between the outer and inner bodies.

8. The sealing device of claim 7, wherein when the seal member is compressed in the certain direction, the cap member substantially inhibits the seal member from extruding into the clearance space.

9. The sealing device of claim 7, wherein when fluid between the outer body and inner body is at a temperature operable to deteriorate the elastomer material of the seal member, the cap member substantially inhibits the elastomer material of the seal member from passing into the clearance space.

10. The sealing device of claim 9, wherein when fluid between the outer body and inner body is at least 350°0 F. and at least 15,000 psi, the cap member substantially inhibits the elastomer material of the seal member from passing into the clearance space.

11. The sealing device of claim 7, wherein when the seal member is disposed in a groove formed in the outer body and the inner body, the cap member is sized to contact the outer and inner bodies so as to substantially inhibit the seal member from blowing out of the groove.

12. A device comprising:

a first body;

a second body having a groove; and

a seal in the groove adapted to substantially seal between the first and second bodies, the seal comprising:

an annular seal member having a first substantially convex surface and a second substantially convex surface; and

a first cap member having a first substantially concave surface affixed to the first substantially convex surface of the seal member such that deformable portions of the first cap member are positioned radially on both sides of a portion of the seal member, and

a second cap member having a second substantially concave surface affixed to the second substantially convex surface of the seal member such that deformable portions of the second cap member are positioned radially on both sides of a portion of the seal member.

13. The device of claim 12, wherein when the seal member is compressed in a substantially axial direction, the deformable portions of the first and second cap members deform in a substantially radial direction.

14. The device of claim 13, wherein at least one of the first and second cap members deforms to press against the first and second bodies.

15. The device of claim 13, wherein at least one of the first and second cap members substantially seals against the first and second bodies.

16. The device of claim 12, wherein when the seal member is compressed in a substantially axial direction, at least one of the first and second cap members substantially inhibits the seal member from extruding into a clearance space between the first and second bodies.

17. The device of claim 12, wherein at least one of the first and second cap members has higher resistance to degradation from temperature than the seal member.

18. The device of claim 12, wherein the first and second bodies are components of a well bore packer assembly.

19. The device of claim 12, wherein at least one of the first and second cap members is sized to contact the outer and inner bodies so as to substantially inhibit the seal member from blowing out of the groove.

20. A method of sealing between a first body and a second body, the second body including a groove, the method comprising:

providing a seal device in the groove having an elastomeric seal member defining a first seal surface to press against the first body and a second seal surface to press against the second body, the seal device having a cap member affixed to an axial side of the seal member and disposed radially between the first and second seal surfaces; and

in response to pressure applied to the seal between the first and second seal surfaces, deforming the cap member to press against the first and second bodies.

21. The method of claim 20, wherein the cap member is provided in contact with the first and second bodies and wherein deforming the cap member to press against the first and second bodies comprises deforming the cap member into further contact against the first and second bodies.

22. The method of claim 20, wherein deforming the cap member to press against the first and second bodies comprises deforming the cap member to substantially seal against the first and second bodies.

23. The method of claim 20, wherein the cap member is affixed to the axial side of the seal member proximal to a clearance space between the first and second bodies, further comprising substantially inhibiting the seal member from extruding into the clearance space.

24. The method of claim 20, wherein the cap member has a higher resistance to degradation from temperature than the elastomer material of the seal member.