Granted Patent
Utility
US 6,725,919 · App. 09/962,467
Forming a wellbore casing while simultaneously drilling a wellbore
Inventors:
Robert Lance Cook, David Paul Brisco, Lev Ring, Michael Bullock
Patented Case
View Patent ↗
Granted: Apr 27, 2004
Filed: Sep 25, 2001
Inventors
Robert Lance Cook
David Paul Brisco
Lev Ring
Michael Bullock
Assignee (at issue)
SHELL OIL COMPANY
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.