Granted Patent
Utility
US 5,114,598 · App. 07/473,474
Method of making drilling fluid containing asphaltite in a dispersed state
Inventors:
Jerry Rayborn, J. Phillip Dickerson
Patented Case
View Patent ↗
Granted: May 19, 1992
Filed: Feb 1, 1990
Inventors
Jerry Rayborn
J. Phillip Dickerson
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.