Granted Patent
Utility
US 6,410,488 · App. 09/523,519
Drilling fluid
Inventors:
Michael Fefer, Lorne Pierson
Patented Case
View Patent ↗
Granted: Jun 25, 2002
Filed: Mar 10, 2000
Inventors
Michael Fefer
Lorne Pierson
Assignee (at issue)
PETRO-CANADA
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.