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Drilling with concentric strings of casing

  • US 6,857,487 B2
  • Filed: 12/30/2002
  • Issued: 02/22/2005
  • Est. Priority Date: 12/30/2002
  • Status: Active Grant
First Claim
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1. A method for setting at least two strings of casing within a wellbore, the at least two strings of casing comprising a second string of casing disposed within a first string of casing, comprising:

  • running a casing working string into the wellbore, the casing working string comprising;

    the at least two strings of casing releasably connected to one another; and

    a drill bit piece disposed at the lower end of at least one of the at least two strings of casing;

    setting the first string of casing within the wellbore;

    releasing the releasable connection between the first string of casing and the second string of casing;

    running the casing working string into the wellbore to a second depth while applying rotational force to the drill bit piece; and

    setting the second string of casing within the wellbore.

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