Granted Patent
Utility
US 5,942,467 · App. 08/986,668
Drilling fluid system containing a combination of hydrophilic carbon black/asphaltite and a refined fish oil/glycol mixture and related methods
Inventors:
Jerry Rayborn, John J. Rayborn
Patented Case
View Patent ↗
Granted: Aug 24, 1999
Filed: Dec 8, 1997
Inventors
Jerry Rayborn
John J. Rayborn
Assignee (at issue)
SUN DRILLING PRODUCTS 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.