发明名称 |
Electromagnetic inspection tool for ferromagnetic casings |
摘要 |
An electromagnetic thickness tool is disclosed to produce a measurement of the wall-thickness of a ferromagnetic casing corrected for the effects of casing permeability. First apparatus provides an uncorrected thickness signal proportional to the thickness of the casing uncorrected for the effects of casing permeability. A second apparatus provides a permeability signal representative of the permeability of the casing. A signal processor uses the mathematical square root of the permeability signal as a correction factor for the uncorrected thickness signal for generating the corrected value. The second apparatus, responsive to a signal proportional to the magnitude of the inside diameter of the casing, corrects the permeability signal for the effects of casing inside diameter.
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申请公布号 |
US4292588(A) |
申请公布日期 |
1981.09.29 |
申请号 |
US19780970671 |
申请日期 |
1978.12.18 |
申请人 |
SCHLUMBERGER TECHNOLOGY CORPORATION |
发明人 |
SMITH, GLENN S. |
分类号 |
E21B47/08;(IPC1-7):G01N27/72;G01N27/82;G01R33/12 |
主分类号 |
E21B47/08 |
代理机构 |
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代理人 |
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地址 |
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