Granted Patent
Utility
US 6,640,903 · App. 09/523,468
Forming a wellbore casing while simultaneously drilling a wellbore
Inventors:
Robert Lance Cook, David Paul Brisco, R. Bruce Stewart, Lev Ring, Robert Donald Mack, Alan B. Duell, Andrei Gregory Filippov
Patented Case
View Patent ↗
Granted: Nov 4, 2003
Filed: Mar 10, 2000
Inventors
Robert Lance Cook
David Paul Brisco
R. Bruce Stewart
Lev Ring
Robert Donald Mack
Alan B. Duell
Andrei Gregory Filippov
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.