Granted Patent
Utility
US 6,571,880 · App. 09/559,243
Method and multi-purpose apparatus for control of fluid in wellbore casing
Inventors:
Charles Butterfield, Robert Bates, David F. Laurel, Samuel P. Hawkins, III, Burney J. Latiolais, Jr., Keith T. Lutgring
Patented Case
View Patent ↗
Granted: Jun 3, 2003
Filed: Apr 26, 2000
Inventors
Charles Butterfield
Robert Bates
David F. Laurel
Samuel P. Hawkins, III
Burney J. Latiolais, Jr.
Keith T. Lutgring
Assignee (at issue)
FRANK'S INTERNATIONAL, LLC
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.