Granted Patent
Utility
US 6,457,529 · App. 09/788,058
Apparatus and method for returning drilling fluid from a subsea wellbore
Inventors:
Ian Calder, Ready Johnson, John E. Nelson
Patented Case
View Patent ↗
Granted: Oct 1, 2002
Filed: Feb 16, 2001
Inventors
Ian Calder
Ready Johnson
John E. Nelson
Assignee (at issue)
ABB Vetco Gray Inc.
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.