Granted Patent
Utility
US 4,388,970 · App. 06/236,144
Apparatus and method for controlling injection fluid flow in a well annulus
Inventor:
John R. Setterberg, Jr.
Patented Case
View Patent ↗
Granted: Jun 21, 1983
Filed: Feb 20, 1981
Inventor
John R. Setterberg, Jr.
Assignee (at issue)
Otis Engineering Corporation
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.