초록 ▼

A well tool having a magnetically coupled position sensor. In operation of a well tool, relative displacement is produced between members of the well tool. A magnetically coupled position sensor includes one magnet assembly attached to a member for displacement therewith and another magnet assembly

A well tool having a magnetically coupled position sensor. In operation of a well tool, relative displacement is produced between members of the well tool. A magnetically coupled position sensor includes one magnet assembly attached to a member for displacement therewith and another magnet assembly movably attached to the other member and magnetically coupled to the first magnet assembly for displacement therewith. The position sensor further includes a magnetically permeable material which increases a magnetic flux density between the magnet assemblies. The magnetically permeable material may be positioned between magnets of the magnet assemblies and/or spaced apart therefrom.

대표청구항 ▼

What is claimed is: 1. A well tool for use in conjunction with a subterranean well, the well tool comprising: first and second members, relative displacement between the first and second members being produced in operation of the well tool; and a magnetically coupled position sensor including first

What is claimed is: 1. A well tool for use in conjunction with a subterranean well, the well tool comprising: first and second members, relative displacement between the first and second members being produced in operation of the well tool; and a magnetically coupled position sensor including first and second magnet assemblies, the first magnet assembly being attached to the first member for displacement with the first member, the second magnet assembly being movably attached to the second member and coupled by a magnetic coupling force to the first magnet assembly for displacement with the first magnet assembly, and the position sensor further including a first magnetically permeable material which increases a magnetic flux density between the first and second magnet assemblies, the first magnetically permeable material being positioned between first and second magnets of the first magnet assembly. 2. The well tool of claim 1, wherein the first magnet has a first pole axis, the second magnet has a second pole axis, and wherein the first and second pole axes are aligned with each other. 3. The well tool of claim 1, wherein the first member is a portion of a closure assembly of the well tool. 4. The well tool of claim 1, wherein the first magnetically permeable material is also positioned at opposite ends of the first and second magnets. 5. The well tool of claim 1, wherein the first magnet assembly includes a housing containing the first and second magnets, the housing isolating the first and second magnets from fluid in the well, and wherein a second magnetically permeable material is positioned external to the housing and aligned with the first magnetically permeable material. 6. A well tool for use in conjunction with a subterranean well, the well tool comprising: first and second members, relative displacement between the first and second members being produced in operation of the well tool; and a magnetically coupled position sensor including first and second magnet assemblies, the first magnet assembly being attached to the first member for displacement with the first member, the second magnet assembly being movably attached to the second member and coupled by a magnetic coupling force to the first magnet assembly for displacement with the first magnet assembly, the first magnet assembly including at least a first magnet having a first pole axis, the second magnet assembly including at least a second magnet having a second pole axis, the first and second pole axes being aligned with each other, and wherein a first magnetically permeable material is positioned between the first and second magnets and straddling the first and second magnets. 7. The well tool of claim 6, wherein the first magnetically permeable material increases a magnetic flux density between the first and second magnet assemblies. 8. The well tool of claim 6, wherein the first and second pole axes are collinear. 9. The well tool of claim 6, wherein the first and second pole axes are parallel to each other. 10. The well tool of claim 6, wherein the first member is a portion of a closure assembly of the well tool. 11. The well tool of claim 6, wherein the first magnet assembly includes a housing containing the first and second magnets, the housing isolating the first and second magnets from fluid in the well. 12. The well tool of claim 6, further comprising a second magnetically permeable material spaced apart from the first and second magnets and aligned with the first magnetically permeable material. 13. A well tool for use in conjunction with a subterranean well, the well tool comprising: first and second members, relative displacement between the first and second members being produced in operation of the well tool; and a magnetically coupled position sensor including first and second magnet assemblies, the first magnet assembly being attached to the first member for displacement with the first member, the second magnet assembly being movably attached to the second member and coupled by a magnetic coupling force to the first magnet assembly for displacement with the first magnet assembly, and the position sensor further including a first magnetically permeable material which increases a magnetic flux density between the first and second magnet assemblies, the first magnetically permeable material being positioned adjacent first and second magnets of the first magnet assembly, and a second magnetically permeable material being spaced apart from the first and second magnets and aligned with the first magnetically permeable material. 14. The well tool of claim 13, wherein the first magnetically permeable material is positioned between the first and second magnets. 15. The well tool of claim 13, wherein the first magnetically permeable material is positioned straddling the first and second magnets. 16. The well tool of claim 13, wherein the first magnet assembly includes a housing containing the first and second magnets, the housing isolating the first and second magnets from fluid in the well. 17. The well tool of claim 16, wherein the second magnetically permeable material is positioned external to the housing. 18. The well tool of claim 13, wherein first and second pole axes of the respective first and second magnets are collinear. 19. The well tool of claim 13, wherein first and second pole axes of the respective first and second magnets are parallel to each other. 20. The well tool of claim 13, wherein the first member is a portion of a closure assembly of the well tool.