Claims
- 1. A sealing apparatus for use in a wellbore to seal a space between a first surface and a second surface to prevent a wellbore fluid flow therethrough, wherein said second surface is moveable relative to said first surface, said sealing apparatus comprising:
- a seal assembly which includes:
- at least one thermoplastic seal member formed from a thermoplastic material which is pliable at a first wellbore temperature, said at least one thermoplastic seal member sealingly engaging said first surface and said second surface to prevent said wellbore fluid flow at a second temperature which is lower than said first temperature;
- a plurality of retainer seal members formed from a high temperature thermoplastic material, said plurality of retainer seal members engaging said first surface and said second surface at said first wellbore temperature in a sealing engagement which seals said space against said wellbore fluid flow and seals said space against extrusion of said at least one thermoplastic seal member;
- wherein said plurality of retainer seal members are disposed adjacent to opposing sides of said at least one thermoplastic seal member to retain said at least one thermoplastic seal member in a selected shape at said first wellbore temperature so that upon cooling to said temperature lower than said first wellbore temperature, said at least one thermoplastic seal member will be shaped to sealingly engage said first surface and said second surface to prevent said wellbore fluid flow; and
- at least one retention member which supportively retains said at least one seal assembly to prevent axial movement of said seal assembly relative to said first surface.
- 2. The sealing apparatus of claim 1, wherein:
- said sealing assembly is urged to sealingly engage said first and second surface at said first temperature by action of both an interference fit of said plurality of retainer seal members between said first surface and said second surface, and a wellbore pressure which urges said wellbore fluid flow; and
- said sealing assembly is urged to sealingly engage said first and second surfaces at said temperature lower than said first temperature by action of both an interference fit between said at least one thermoplastic seal member and said plurality of retainer seal members, and said wellbore pressure which urges said wellbore fluid flow.
- 3. The sealing apparatus of claim 1, wherein said seal assembly sealingly engages said first surface and said second surface:
- after exposure to numerous thermocycles of being heated to said first wellbore temperature and then cooled to said temperature lower than said first temperature; and
- after prolonged exposure to said first wellbore temperature and after numerous repeated movements of said second surface relative to said first surface and said sealing assembly.
- 4. The sealing apparatus of claim 1 wherein:
- said thermoplastic material is polytetrafluoroethylene based composure thermoplastic; and
- said high temperature thermoplastic material is polyetherketone.
- 5. The sealing apparatus of claim 1, wherein:
- said at least one thermoplastic seal member has a cross-section including opposing sides of a generally inwardly protruding shape and a generally outwardly protruding shape;
- said plurality of retainer seal members have a retainer cross-section including opposing sides of a retainer generally inwardly protruding shape and a retainer generally outwardly protruding shape; and
- said retainer generally outwardly protruding shape has an interference fit with said generally inwardly protruding shape wherein said retainer generally outwardly protruding shape when forcibly mated with said generally inwardly protruding shape will urge an expansion of said generally inwardly protruding shape.
- 6. The sealing apparatus of claim 5, wherein:
- said first surface comprises a first cylindrical surface; and
- said second surface comprises a second cylindrical surface concentric with said first surface;
- said at least one thermoplastic seal member is formed in a shape of a cylindrical ring having a cross-section including axially opposing sides of a generally inwardly protruding shape and a generally outwardly protruding shape;
- said plurality of retainer seal members are formed in a shape of a second cylindrical ring having a retainer cross-section including axially opposing sides of a retainer generally inwardly protruding shape and a retainer generally outwardly protruding shape; and
- said retainer cross-section includes said retainer generally outwardly protruding shape having an interference fit with said generally inwardly protruding shape of said cross-section, wherein said retainer generally outwardly protruding shape when forcibly mated with said generally inwardly protruding shape will urge an expansion of said generally inwardly protruding shape.
- 7. The sealing apparatus of claim 1, wherein:
- said at least one thermoplastic seal member defines a substantially chevron shape in radial cross-section view.
- 8. The sealing apparatus of claim 1, wherein:
- said at least one thermoplastic seal member is shaped as a circumferentially continuous cylindrical ring of a generally chevron shape in radial cross-section; and
- said plurality of retainer seal members are each shaped as said circumferentially continuous ring of a generally chevron shape in radial cross-section.
- 9. A seal member for use in a sealing apparatus which is used in a wellbore tool to sealingly engage a moveable surface of a noncontinuously mating moveable member to prevent a flow of a wellbore fluid along said moveable surface of said noncontinuously mating moveable member, said seal member comprising:
- a dynamic engagement wing defining a portion of said seal member which is disposed to engage said noncontinuously mating moveable member, said dynamic engagement wing at least in part defined by:
- an active end surface which faces said flow of said wellbore fluid;
- a passive end surface which is oppositely disposed across said outer wing from said active end surface;
- a dynamic engagement wing surface which includes a sealing surface which sealingly engages said noncontinuously mating moveable member;
- wherein said active end surface which faces said flow of said wellbore fluid at least in part being defined by:
- an inwardly protruding surface which is shaped to provide a sealing energization so that when said inwardly protruding surface is pressed by said wellbore fluid said sealing surface is pushed into sealing engagement with said moveable surface of said noncontinuously mating moveable member; and
- a blunt wing surface which is disposed intermediate of said active end surface and said dynamic engagement wing surface, and which is sized to provide a balance in a rigidity of said dynamic engagement wing which is stiff to prevent displacement of said dynamic engagement wing into a path of said moveable surface of said noncontinuously mating moveable member, and flexible to allow said sealing energization of said wellbore fluid pushing said sealing surface into sealing engagement.
- 10. The seal member of claim 9, wherein the moveable surface of said noncontinuously mating moveable member is defined by a cylindrical shape, and said seal member further comprising:
- a cylindrical ring having a radial cross-section of a generally chevron shape which includes:
- a crotch which is defined by a generally inwardly protruding chevron surface, a portion of which defines said inwardly protruding surface of said active end surface of said dynamic engagement wing;
- a nose which is defined by a generally outwardly protruding chevron surface, a portion of which defines said passive end surface of said dynamic engagement wing;
- said dynamic engagement wing surface disposed from said moveable surface at a sealing surface inclination angle, and defining said sealing surface; and
- said blunt wing surface defined by a flat radial surface.
- 11. The seal member of claim 10, wherein said noncontinuously mating moveable member comprises:
- a ported moveable member, which includes said moveable surface which said seal member sealingly engages;
- said moveable surface includes at least one port therethrough, and wherein mating is noncontinuous between said moveable surface and said seal member when said at least one port passes by said seal member; and
- said path of said moveable surface at least in part defined by a trailing edge of said at least one port through said moveable surface.
- 12. The seal member of claim 10, wherein said noncontinuously mating moveable member further comprises a housing which is disposed in a production tubing string disposed within said wellbore, and said housing includes an inner cylindrical nipple surface which defines said moveable surface which is sealingly engaged by said seal member when said seal member is moved into said housing.
- 13. The apparatus of claim 10, wherein said noncontinuously mating moveable member comprises a seating assembly inside of a wellbore packer, and wherein said seal member comprises a sealing assembly stem which sealingly engages said moveable surface when said sealing assembly stem is lowered inside of said seating assembly.
- 14. The apparatus of claim 10, wherein said seal member is comprised of thermoplastic.
- 15. A seal assembly for use in a wellbore to sealingly engage a moveable surface in a noncontinuously mating engagement in which said moveable surface includes an edge which is moved across said seal assembly, said seal assembly comprising:
- a thermoplastic seal member having a wing portion extending therefrom for sealingly engaging said moveable surface to prevent a fluid flow therebetween;
- a means for pressing said thermoplastic seal member into sealingly engaging said moveable surface to prevent said fluid flow therebetween;
- a retainer means for supporting said thermoplastic seal member against said means for pressing; and
- said wing portion of said thermoplastic seal member having an end thickness for providing sufficient rigidity to prevent said means for pressing from urging said wing portion substantially into a path of said edge of said moveable member, and thus preventing said edge from damaging said thermoplastic seal member.
- 16. The seal assembly of claim 15 further comprising:
- said retainer means including first and second retainer members, each having a wing portion extending therefrom for sealingly engaging said moveable surface for preventing said fluid flow when said thermoplastic seal member is heated to a temperature at which said thermoplastic seal member substantially softens to a pliability at which said end thickness would not prevent said means for pressing from urging said part of said wing portion substantially into said path of said edge of said moveable member; and
- said theremoplastic seal member disposed between said first and second retainer members, to protect said thermoplastic seal member from damage when heated to said temperature so that said thermoplastic seal member later sealingly engages said moveable surface when cooled to a lower temperature at which said end thickness of thermoplastic seal member prevents said means for pressing from urging said wing portion substantially into said path of said edge of said movable member.
- 17. The seal assembly of claim 10, wherein said first and second retainer members are formed from a high temperature thermoplastic.
- 18. The seal assembly of claim 16, wherein said first and second retainer members together retain said thermoplastic seal member in substantially an initial shape for sealingly engaging said moveable surface to prevent said fluid flow after cooling below said temperature.
- 19. The seal assembly of claim 15, wherein said thermoplastic seal member sealingly engages said moveable surface to prevent said fluid flow in a first direction only, and said seal assembly further comprises:
- a second thermoplastic seal member and second retainer means which prevent said fluid flow in a second direction, which is opposite of said first direction.
- 20. A thermoplastic seal assembly for sealingly engaging a surface having an edge which said thermoplastic seal assembly moves across while urged to sealingly engage said surface, said thermoplastic seal assembly comprising:
- a thermoplastic seal member having a wing portion extending therefrom for sealingly engaging said moveable surface to prevent a fluid flow therethrough;
- a means for pressing said thermoplastic seal member into said surface for sealingly engaging said surface to prevent said fluid flow therethrough;
- a pair of thermoplastic retainer members, with at least one of said pair of retainer members disposed on each of two opposing sides of said thermoplastic seal member for holding an initial shape of said thermoplastic seal member against said means for pressing; and
- wherein said thermoplastic seal member, disposed between said pair of thermoplastic retainer members, includes an end thickness for preventing said means for pressing from urging said thermoplastic seal member substantially beyond said edge of said surface to prevent damage to said thermoplastic seal member when passing across said edge.
- 21. The thermoplastic seal assembly of claim 20, wherein said pair of thermoplastic retainer members are formed from a high temperature thermoplastic for sealingly engaging said surface at a temperature, above which said thermoplastic seal member softens so that said end thickness does not prevent said means for pressing from urging said thermoplastic seal member to extend beyond said edge of said surface.
- 22. The thermoplastic seal assembly of claim 20, wherein said thermoplastic seal member sealingly engages said surface for preventing said fluid flow in a first direction only, and said thermoplastic seal assembly further comprises:
- at least one more thermoplastic seal member which is substantially the same as said thermoplastic seal member for said means for pressing to urge into sealingly engaging said surface to prevent said fluid flow in a second direction, which is opposite of said first direction; and
- at least one more thermoplastic retainer member for securing each of said at least one more thermoplastic seal members between at least two thermoplastic retainer members for holding an initial shape of each of said thermoplastic seal members against said means for pressing.
- 23. The thermoplastic seal assembly of claim 20, wherein said thermoplastic seal member is at least in part formed from polytetrafluroethylene; and
- wherein said pair of thermoplastic retainer members are at least in part formed from polyetherketone.
- 24. A sealing assembly for use in a wellbore tool to seal an annular space between a first and second surfaces to prevent a wellbore fluid flow therethrough, wherein said first and second surfaces are concentrically disposed and each have a generally cylindrical shape and are axially moveable with respect to each other in a noncontinuously mating engagement, said sealing assembly comprising:
- at least one thermoplastic seal ring formed from a thermoplastic material which is pliable at a high wellbore temperature, said at least one thermoplastic seal ring sealingly engaging between said first and second surfaces for preventing said wellbore fluid flow through said annular space at a temperature lower than said high wellbore temperature, said at least one thermoplastic seal ring being formed in a shape with a cross-section including opposing sides of a generally inwardly protruding shape and a generally outwardly protruding shape;
- a plurality of retainer seal rings formed from a high temperature thermoplastic material, said plurality of retainer seal rings sealingly engaging between said first and second members for preventing both said wellbore fluid flow though said annular space and extrusion of said at least one thermoplastic seal ring at said high temperature, said plurality of retainer seal rings formed in a shape with said cross-section including opposing sides of said generally inwardly protruding shape and said generally outwardly protruding shape, wherein said generally outwardly protruding shape has a mating engagement with said generally inwardly protruding shape, with said mating engagement having an interference fit wherein said generally outwardly protruding shape when forcibly in said mating engagement with said generally inwardly protruding shape will urge an expansion of said generally inwardly protruding shape;
- wherein said at least one thermoplastic seal ring and said plurality of retainer seal rings are secured to said first member for sealingly engaging said second member and moving past an edge of said second member; and
- wherein one of said plurality of retainer seal rings is disposed adjacent to and in said mating engagement with each axial end of each of said at least one thermoplastic seal ring for retaining said shape of said at least one thermoplastic seal ring at said high wellbore temperatures so that said at least one thermoplastic seal ring will, upon cooling to said temperature lower than said high wellbore temperature, sealingly engage between said first and second surfaces for preventing said wellbore fluid flow.
- 25. The sealing assembly of claim 24, wherein said sealing assembly is urged to sealingly engage between said first and second surfaces at said high temperatures by action of both a diametrical interference fit of said plurality of retainer seal rings between said first and second surfaces, and a wellbore pressure which urges said wellbore fluid flow.
- 26. The sealing assembly of claim 24, wherein said sealing assembly urged to sealingly engage said housing and said moveable member at said temperature lower than said high temperatures by action of both an axial interference fit between said at least one thermoplastic seal ring and said plurality of retainer seal rings, and said wellbore pressure which urges said wellbore fluid flow.
- 27. The sealing assembly of claim 24, wherein at least one thermoplastic ring and said plurality of retainer seal rings define a generally chevron shape in radial cross-section.
- 28. The sealing apparatus of claim 27, wherein said generally chevron shape includes:
- a nose formed by two outwardly protruding surfaces converging at a nose angle;
- a crotch formed by two inwardly protruding surfaces converging at a crotch angle;
- a nose formed at a nose angle which is less than 20 degrees greater than a crotch angle of said generally chevron shape define said axial interference fit;
- said axial interference fit defined by the amount said nose angle is greater than said crotch angle; and
- at least one chevron sealing surface disposed at a friction reducing inclination angle from a dynamic sealing surface of said moveable member.
- 29. The sealing apparatus of claim 28, with said generally chevron shape further including:
- said nose formed with said nose angle equal to 96 degrees and said crotch formed with said crotch angle equal to 86 degrees to define said axial interference fit; and
- said at least one chevron sealing surface disposed from said dynamic sealing surface at said friction reducing inclination angle of 3 degrees.
- 30. The sealing apparatus of claim 24, wherein said thermoplastic material is comprised of polytetrafluroethylene thermoplastic, and said high temperature thermoplastic material comprised of polyetherketone.
- 31. The sealing apparatus of claim 24, wherein said sealing assembly sealingly engages between said first and second surfaces after exposure to numerous thermocycles of being heated to said high wellbore temperature and then cooled to said lower temperature, prolonged exposure to said high wellbore temperature, and after numerous repeated movements of said edge across said seal assembly with pressure urging wellbore fluid flow.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of the earlier application Ser. No. 07/573,581, filed Aug. 27, 1990, now U.S. Pat. No. 5,156,220 and Ser. No. 07/751,350 Filed Apr. 28, 1991, both entitled Well Tool With Sealing Means.
US Referenced Citations (8)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
573581 |
Aug 1990 |
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