The invention provides a method and apparatus for setting concentric casing strings within a wellbore in one run-in of a casing working string.
Offshore staff
U.S. patent number US7131505 Appl. Data: 11 20050222 Applicant Weatherford/Lamb Inc. Inventors Galloway, Gregory G. Brunnert, David J.
The invention provides a method and apparatus for setting concentric casing strings within a wellbore in one run-in of a casing working string. In one aspect of the invention, the apparatus comprises a drilling system comprising concentric casing strings, with each casing string having a drill bit disposed at the lower end thereof. The drill bit pieces of adjacent casing strings are releasably connected to one another. In another aspect of the invention, a method is provided for setting concentric casing strings within a wellbore with the drilling system. In another aspect of the invention, the releasably connected drill bit pieces comprise a drill bit assembly.
