초록 ▼

In order to prevent potential electrical hazards associated with supplying power downhole, a hanger is provided for either casing or tubing strings, or a plurality of casing or tubing strings, that electrically insulates the internal suspension mechanism of the hanger from the hanger's external seal

In order to prevent potential electrical hazards associated with supplying power downhole, a hanger is provided for either casing or tubing strings, or a plurality of casing or tubing strings, that electrically insulates the internal suspension mechanism of the hanger from the hanger's external seal. Electrical power is typically transferred through a hanger by way of the internal suspension mechanism. If electrical umbilicals are used, connecting devices may be located within the internal suspension mechanism for connecting an upper and lower umbilical and transferring power trough the hanger. If a rigid tubular conductor is used, the suspension mechanism may be ported to allow the passage of electrical feedthroughs or, in the case of tubing hangers, the tubing itself may be charged with electrical power. By insulating the suspension mechanism from the external seal potential electrical hazards are eliminated.

대표청구항 ▼

1. An insulated hanger for suspending at least one inner pipe string within a wellhead comprising:an internal suspension means for suspending said at least one inner pipe string;an inner body fixedly secured around said internal suspension means, said inner body comprising an upper cylindrical secti

1. An insulated hanger for suspending at least one inner pipe string within a wellhead comprising:an internal suspension means for suspending said at least one inner pipe string;an inner body fixedly secured around said internal suspension means, said inner body comprising an upper cylindrical section, a lower cylindrical section, and a middle cylindrical section;an upper annular insulating member slidingly engaged around said upper cylindrical section of said inner body, said upper annular insulating member having a top end and a bottom end, said top end having a first diameter and said bottom end having a second diameter greater than said first diameter;a lower annular insulating member slidingly engaged around said lower cylindrical section of said inner body, said lower annular insulating member having a top end and a bottom end, said bottom end having a first diameter and said top end having a second diameter greater than said first diameter;a sealing ring slidingly engaged around said middle cylindrical section of said inner body, said sealing ring having a top face engaged with said bottom end of said upper annular insulating member and a bottom face engaged with said top end of said lower annular insulating member; andan outer body fixedly secured around said top end of said lower annular insulating member, said sealing ring and said bottom end of said upper annular insulating member, said outer body having an exterior face and said exterior face of said outer body comprising a means for sealing said exterior face within said wellhead. 2. The insulated hanger of claim 1, wherein said upper cylindrical section and said lower cylindrical section of said inner body have substantially equivalent diameters and said middle cylindrical section of said inner body has a diameter greater than said upper and said lower cylindrical sections. 3. The insulated hanger of claim 1, wherein said internal suspension means is a slip-type suspension means. 4. The insulated hanger of claim 1, wherein said internal suspension means is a welded mandrel-type suspension means. 5. The insulated hanger of claim 1, wherein said internal suspension means is a threaded mandrel-type suspension means. 6. The insulated hanger of claim 1, wherein said upper annular insulating member and said lower annular insulating member comprise an insulating material selected from the group consisting of chlorinated polyvinyl chloride, polyoxymethylene, polyamide, polybenzimidazole, polyethylene terephthalate polyester, polyphenylene oxide-styrene alloy, polyetherethylketone, polycarbonate, polyetherimide, polyimide, polypropylene, polysulfone, polyphenylene sulfide, polytetrafluoroethylene, and polyamide-imide. 7. The insulated hanger of claim 1, wherein said upper annular insulating member and said lower annular insulating member comprise polyetherethylketone. 8. The insulated hanger of claim 1, wherein said upper annular insulating member and said lower annular insulating member comprise an insulating composite material selected from the group consisting of fiberglass reinforced epoxy resin, paper reinforced phenolic resin, cotton canvas reinforced phenolic resin and cotton linen reinforced phenolic resin. 9. The insulated hanger of claim 1, wherein said upper annular insulating member and said lower annular insulating member comprise fiberglass reinforced epoxy resin. 10. The insulated hanger of claim 1, wherein said upper annular insulating member and said lower annular insulating member comprise a material having a dielectric strength of at least about 250 volts per mil. 11. The insulated hanger of claim 1, wherein said means for sealing said exterior face of said outer body comprises a plurality of sealing grooves disposed around said exterior face of said outer body and a plurality of sealing rings disposed within said sealing grooves. 12. The insulated hanger of claim 1, wherein said inner body further comprises a means for transferring electrical power fr om a source above said insulated hanger to a electrically responsive device below said insulated hanger. 13. An insulated hanger for suspending an inner pipe string within a wellhead comprising:an internal slip means for suspending said inner pipe string, said internal slip means comprising a cylindrical slip body having a top edge, a bottom edge, a substantially smooth external surface and an inclined internal surface, said inclined internal surface beginning at said top edge of said cylindrical slip body and progressing downwardly and inwardly towards said bottom edge of said cylindrical slip body, a plurality of slip members disposed circumferentially about said inclined internal surface of said cylindrical slip body and forming a central bore, said slip members having an inner surface with a series of teeth engageable into said inner pipe string disposed in said central bore, a sealing ring in communication with said bottom edge of said cylindrical slip body, a bottom packing plate, said bottom packing plate having means for securing said sealing ring substantially between said cylindrical slip body and said bottom packing plate, and a gland in communication with said top edge of said cylindrical slip body, said gland securing said slip members within said cylindrical slip body;an inner body disposed around said internal slip means, said inner body comprising an upper cylindrical section, a lower cylindrical section, and a middle cylindrical section; an upper annular insulating member slidingly engaged around said upper cylindrical section of said inner body, said upper annular insulating member having a top end and a bottom end; a lower annular insulating member slidingly engaged around said lower cylindrical section of said inner body, said lower annular insulating member having a top end and a bottom end; a sealing ring slidingly engaged around said middle cylindrical section of said inner body, said sealing ring having a top face engaged with said bottom end of said upper annular insulating member and a bottom face engaged with said top end of said lower annular insulating member; and an outer body fixedly secured around said lower annular insulating member, said sealing ring and said upper annular insulating member, said outer body having an exterior face and said exterior face of said outer body comprising a means for sealing said exterior face within said wellhead. 14. The insulated hanger of claim 13, wherein said upper cylindrical section and said lower cylindrical section of said inner body have substantially equivalent diameters and said middle cylindrical section of said inner body has a diameter greater than said upper and said lower cylindrical sections. 15. The insulated hanger of claim 13, wherein said upper annular insulating member comprises a top end having a first diameter and a bottom end having a second diameter greater than said first diameter of said top end of said upper annular insulating member, said lower annular insulating member comprises a bottom end having a first diameter and a top end having a second diameter greater than said first diameter of said bottom end of said lower annular insulating member, and said outer body is fixedly secured around said top end of said lower annular insulating member, said sealing ring and said bottom end of said upper annular insulating member. 16. The insulated hanger of claim 13, wherein said upper annular insulating member and said lower annular insulating member comprise an insulating material selected from the group consisting of chlorinated polyvinyl chloride, polyoxymethylene, polyamide, polybenzimidazole, polyethylene terephthalate polyester, polyphenylene oxide-styrene alloy, polyetherethylketone, polycarbonate, polyetherimide, polyimide, polypropylene, polysulfone, polyphenylene sulfide, polytetrafluoroethylene, and polyamide-imide. 17. The insulated hanger of claim 13, wherein said upper annular insulating member and said lower annular insulating member comprise polyetherethylketone. 18. The insulated hanger of claim 13, wherein said upper annular insulating member and said lower annular insulating member comprise an insulating composite material selected from the group consisting of fiberglass reinforced epoxy resin, paper reinforced phenolic resin, cotton canvas reinforced phenolic resin and cotton linen reinforced phenolic resin. 19. The insulated hanger of claim 13, wherein said upper annular insulating member and said lower annular insulating member comprise fiberglass reinforced epoxy resin. 20. The insulated hanger of claim 13, wherein said upper annular insulating member and said lower annular insulating member comprise a material having a dielectric strength of at least about 250 volts per mil. 21. The insulated hanger of claim 13, wherein said means for sealing said exterior face of said outer body comprises a plurality of sealing grooves disposed around said exterior face of said outer body and a plurality of sealing rings disposed within said sealing grooves. 22. The insulated hanger of claim 13, wherein said inner body further comprises a means for transferring electrical power from a source above said insulated hanger to a electrically responsive device below said insulated hanger. 23. An insulated hanger for suspending an inner pipe string within a wellhead comprising:an internal threaded mandrel-type suspension means for suspending said inner pipe string, said internal mandrel-type suspension means comprising an tubular mandrel comprising an upper end and a lower end and at least one set of threads disposed along the exterior surface of said mandrel;an inner body disposed around said internal mandrel-type suspension means, said inner body comprising an upper cylindrical section having threads on the inside surface of said upper cylindrical section, a lower cylindrical section having threads on the inside surface of said lower cylindrical section, and a middle cylindrical section;an upper annular insulating member slidingly engaged around said upper cylindrical section of said inner body, said upper annular insulating member having a top end and a bottom end, said top end having a first diameter and said bottom end having a second diameter greater than said first diameter;a lower annular insulating member slidingly engaged around said lower cylindrical section of said inner body, said lower annular insulating member having a top end and a bottom end, said bottom end having a first diameter and said top end having a second diameter greater than said first diameter;a sealing ring slidingly engaged around said middle cylindrical section of said inner body, said sealing ring having a top face engaged with said bottom end of said upper annular insulating member and a bottom face engaged with said top end of said lower annular insulating member; andan outer body fixedly secured around said top end of said lower annular insulating member, said sealing ring and said bottom end of said upper annular insulating member, said outer body having an exterior face and said exterior face of said outer body comprising a means for sealing said exterior face within said wellhead. 24. The insulated hanger of claim 23, wherein said upper cylindrical section and said lower cylindrical section of said inner body have substantially equivalent diameters and said middle cylindrical section of said inner body has a diameter greater than said upper and said lower cylindrical sections. 25. The insulated hanger of claim 23, wherein said upper annular insulating member and said lower annular insulating member comprise an insulating material selected from the group consisting of chlorinated polyvinyl chloride, polyoxymethylene, polyamide, polybenzimidazole, polyethylene terephthalate polyester, polyphenylene oxide-styrene alloy, polyetherethylketone, polycarbonate, polyetherimide, polyimide, polypropylene, polysulfone, polyphenylene sulfide, polytetrafluoroethylene, and polyamide-imide. 26. The insulated hanger of claim 23, wherein said upper annular insulating member and said lower annular insulating member comprise polyetherethylketone. 27. The insulated hanger of claim 23, wherein said upper annular insulating member and said lower annular insulating member comprise an insulating composite material selected from the group consisting of fiberglass reinforced epoxy resin, paper reinforced phenolic resin, cotton canvas reinforced phenolic resin and cotton linen reinforced phenolic resin. 28. The insulated hanger of claim 23, wherein said upper annular insulating member and said lower annular insulating member comprise fiberglass reinforced epoxy resin. 29. The insulated hanger of claim 23, wherein said upper annular insulating member and said lower annular insulating member comprise a material having a dielectric of at least about 250 volts per mil. 30. The insulated hanger of claim 23, wherein said means for sealing said exterior face of said outer body comprises a plurality of sealing grooves disposed around said exterior face of said outer body and a plurality of sealing rings disposed within said sealing grooves. 31. The insulated hanger of claim 23, wherein said inner body further comprises a means for transferring electrical power from a source above said insulated hanger to a electrically responsive device below said insulated hanger.