초록 ▼

A check valve has a valve member flexibly attached to a seat with resilient members that fold in response to flow above a predetermined value to shut the valve. The flexibly extending members store potential energy that is released to separate the valve member from the seat when the pressure applied

A check valve has a valve member flexibly attached to a seat with resilient members that fold in response to flow above a predetermined value to shut the valve. The flexibly extending members store potential energy that is released to separate the valve member from the seat when the pressure applied against the seated valve member declines to the point that the potential energy stored in the flexible members is able to move the valve member off the seat. The valve assembly including the valve member, the seat and the flexible members can be a common material, or can be all one or more nonmetallic materials or involve composites or other easily drilled materials that are compatible with the operating conditions of pressure differential, temperature and composition of the well fluid. The check valve assembly can be pushed with pressure when closed to operate a subterranean tool.

대표청구항 ▼

1. A check valve for a tubular in subterranean treatment use, comprising: a seat in the tubular having an opening therethrough;a valve member non-releasably retained in a spaced relation to said opening in said seat when there is no flow and up to a predetermined flow rate in a forward direction, fr

1. A check valve for a tubular in subterranean treatment use, comprising: a seat in the tubular having an opening therethrough;a valve member non-releasably retained in a spaced relation to said opening in said seat when there is no flow and up to a predetermined flow rate in a forward direction, from uphole to downhole, by force delivered from at least one flexible member extending from said seat and located peripherally to said opening;said at least one flexible member flexing radially toward the tubular to bring said valve member into sealing contact with said seat to close said opening when said predetermined flow rate is exceeded. 2. The check valve of claim 1, wherein: said seat, valve member and at least one flexible member are made of one piece. 3. The check valve of claim 1, wherein: said seat, valve member and at least one flexible member are made of non-metallic material. 4. The check valve of claim 1, wherein: said at least one flexible member comprises a plurality of spaced flexible members positioned to restrain relative rotation between said valve member and said seat. 5. The check valve of claim 1, wherein: said at least one flexible member flexes by bending in at least one location between opposed ends thereof, said ends attached to said seat and said valve member respectively. 6. The check valve of claim 1, wherein: said valve member having a tapered leading end that at least in part enters said opening when contacting said seat. 7. The check valve of claim 1, wherein: said seat further comprises a sealing surface immediately surrounding said opening;said valve member having a parallel surface to said sealing surface for circumferential contact all-around said sealing surface. 8. The check valve of claim 7, wherein: said sealing surface further comprising a composite, single or multiple compound elastomer or a metal. 9. The check valve of claim 3, wherein: said non-metallic comprises an elastomer. 10. The check valve of claim 1, wherein: said valve member having a flat leading end that does not enter said opening when contacting said seat. 11. A subterranean formation treatment method, comprising: providing a seat in a tubular having an opening therethrough;a valve member non-releasably retained in a spaced relation to said opening in said seat when there is no flow and up to a predetermined flow rate in a forward direction, from uphole to downhole, by force delivered from at least one flexible member extending from said seat and located peripherally to said opening;said at least one flexible member flexing radially toward the tubular to bring said valve member into sealing contact with said seat to close said opening when said predetermined flow rate is exceeded; andpressurizing against said at least one flexible member to perform a treatment into a surrounding formation. 12. A subterranean formation treatment method comprising: operating on a tubular string a check valve assembly that does not substantially move a valve member and restrict flow coming into the string when running in, said valve member permits flow in a forward direction, from uphole to downhole, out of the string up to a predetermined flow rate above which flow rate said valve member engages a seat to prevent flow out of said string;attaching at least one radially flexible support member between said valve member and said seat and radially flexing said support member toward the tubular string when said valve member contacts said seat;performing a treatment when said valve member engages said seat. 13. The method of claim 12, comprising: non-releasably supporting said valve member from said seat with said at least one flexible support member. 14. The method of claim 13, comprising: providing said valve member, seat and support member as a single piece. 15. The method of claim 13, comprising: providing said valve member, seat and support member in a single non-metallic material. 16. The method of claim 15, comprising: making said material an elastomer. 17. The method of claim 13, comprising: providing a plurality of circumferentially spaced flexible support members as said at least one flexible support member;retaining said valve member against relative rotation with respect to said seat;milling out said valve member with said valve member retained against relative rotation with respect to said seat. 18. The method of claim 17, comprising: bending said flexible support members in response to flow to store potential energy as said valve member moves toward said seat in response to flow out of said string;releasing said potential energy to space said valve member from said seat when pressure on said valve member holding said valve member to said seat declines below a predetermined quantity;connecting said valve member and said seat at opposed ends of said flexible support members. 19. The method of claim 12, comprising: delivering a perforating gun using flow out of said string at or below said predetermined flow rate;creating openings in said tubular string with said perforating gun for said performing a treatment. 20. The method of claim 12, comprising: removing an initial perforating gun from said tubular string if said gun fails to fire;delivering a redressed said perforating gun or a replacement perforating gun using flow out of said string at or below said predetermined flow rate;creating openings in said tubular string for said performing a treatment with either said gun. 21. An assembly of a check valve and a subterranean tool for a tubular in subterranean treatment use, comprising: a seat in the tubular having an opening therethrough;a valve member non-releasably retained in a spaced relation to said opening in said seat when there is no flow and up to a predetermined flow rate in a forward direction, from uphole to downhole, by force delivered from at least one flexible member extending from said seat and located peripherally to said opening; said at least one flexible member flexing radially toward the tubular to bring said valve member into sealing contact with said seat to close said opening when said predetermined flow rate is exceeded;said seat movably mounted for selective pressure induced tandem movement with the subterranean tool when said valve member is in contact with said seat. 22. The assembly of claim 21, wherein: said seat, valve member and at least one flexible member are made of one piece. 23. The assembly of claim 21, wherein: said seat, valve member and at least one flexible member are made of non-metallic material. 24. The assembly of claim 21, wherein: said at least one flexible member comprises a plurality of spaced flexible members positioned to restrain relative rotation between said valve member and said seat. 25. The assembly of claim 21, wherein: said at least one flexible member flexes by bending in at least one location between opposed ends thereof, said ends attached to said seat and said valve member respectively. 26. The assembly of claim 21, wherein: said valve member having a tapered leading end that at least in part enters said opening when contacting said seat. 27. The assembly of claim 21, wherein: said seat further comprises a sealing surface immediately surrounding said opening;said valve member having a parallel surface to said sealing surface for circumferential contact all-around said sealing surface. 28. The assembly of claim 27, wherein: said sealing surface further comprising a composite, single or multiple compound elastomer or a metal. 29. The assembly of claim 23, wherein: said non-metallic comprises an elastomer. 30. The assembly of claim 21, wherein: said tandem movement is in at least an axial direction. 31. The assembly of claim 21, wherein: said subterranean tool further comprises a sliding sleeve. 32. The assembly of claim 21, wherein: said seat is mounted adjacent the subterranean tool in the tubular when run to the subterranean location or thereafter delivered to the subterranean tool with the tubular at the subterranean location. 33. A subterranean formation treatment method comprising: running in on a tubular string or subsequently delivering through the tubular string a check valve assembly that does not substantially move a valve member and restrict flow coming into the string when running in, said valve member permits flow out of the string up to a predetermined flow rate above which flow rate out of said string said valve member engages a seat as at least one flexible support member that connects said valve member to said seat flexes radially to prevent flow out of said string from below said seat;displacing said check valve assembly with pressure applied to said valve member when engaged to said seat to operate a subterranean tool with said displacing;performing a treatment after said subterranean tool is operated. 34. The method of claim 33, comprising: non-releasably supporting said valve member from said seat with said at least one flexible support member. 35. The method of claim 34, comprising: providing said valve member, seat and said flexible support member as a single piece. 36. The method of claim 34, comprising: providing said valve member, seat and said flexible support member in a single non-metallic material. 37. The method of claim 36, comprising: making said material an elastomer. 38. The method of claim 34, comprising: providing a plurality of circumferentially spaced flexible support members as said at least one flexible support member;retaining said valve member against relative rotation with respect to said seat when milling out said valve member. 39. The method of claim 38, comprising: bending said flexible support members in response to flow to store potential energy as said valve member moves toward said seat in response to flow out of said string;releasing said potential energy to space said valve member from said seat when pressure on said valve member holding said valve member to said seat declines below a predetermined quantity;connecting said valve member and said seat at opposed ends of said flexible support members. 40. The method of claim 33, comprising: delivering a perforating gun using flow out of said string at or below said predetermined flow rate;creating openings in said tubular string for said performing a treatment with said gun. 41. The method of claim 33, comprising: operating a sliding sleeve valve as said subterranean tool.