发明名称 |
MAGNETIC SENSOR SYSTEM USEFUL FOR DETECTING TOOL JOINTS IN A DOWNHOLD TUBING STRING |
摘要 |
A method and apparatus for detecting ferrous changes passing axially through a cylindrical space. In one embodiment, the method comprises surrounding the cylindrical space with a nonmagnetic cylinder having an outer wall and a cylindrical axis; creating an alternating magnetic field in the cylindrical space, the magnetic field created by a rotatable permanent magnet; monitoring the magnetic field with magnetic flux sensors placed outside the outer walls; and detecting changes in the magnetic field as ferrous matter passes axially through the cylindrical space. In other embodiments, the apparatus identifies ferrous changes as the tool joints that connect a jointed tubing string as the tubing string is moved in or out of a well bore, or as the presence or absence of a coiled tubing string in the well bore.
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申请公布号 |
US2003193329(A1) |
申请公布日期 |
2003.10.16 |
申请号 |
US20020125005 |
申请日期 |
2002.04.16 |
申请人 |
THOMAS ENERGY SERVICES, INC. |
发明人 |
RELTON MAHENDRAN;BURRINGTON JOHN;MACINNIS JASON;FALCON JONATHAN |
分类号 |
E21B19/00;E21B47/09;G01N27/90;(IPC1-7):G01N27/72;G01R33/12 |
主分类号 |
E21B19/00 |
代理机构 |
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