置于任一射孔层段的一段厚壁油管，这时生产油管必须通过此射孔层段，如在多层完井中所要求的。
A section of heavy walled tubing that is placed across any perforated interval through which the production tubing must pass, such as may be required in multiple zone completions.
提出采用主磁通与漏磁通相结合的方法检测在用油管剩余壁厚的方法。
A measuring method combining main magnetic flux and magnetic flux leakage for approaching the residual wall thickness of the oil well tubing in-service was presented.
文中研究了油管局部缺陷和壁厚减薄缺陷的漏磁场检测原理。
Based on the magnetic leakage flux technique, the principle of localized defect inspection and wall thickness measurement in oil well tubing has been researched.
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