Granted Patent
Utility
US 5,663,121 · App. 08/362,761
Method and apparatus for providing a stream of inert gases in underbalanced drilling of a well bore
Inventor:
Eugene I. Moody
Patented Case
View Patent ↗
Granted: Sep 2, 1997
Filed: Dec 22, 1994
Inventor
Eugene I. Moody
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.