| 摘要 |
There is disclosed an assembly of parts for use in cementing a casing string in a well bore comprising a float collar connectible as part of the string, a cement plug lowerable onto the collar, and a wiper plug lowerable onto the cement plug, the lower end of the cement plug having threads for limited make-up with threads on the upper end of the collar and the lower end of the wiper plug having threads for limited make-up with the cement plug, so as to limit rotation between them.
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