Granted Patent
Utility
US 5,957,539 · App. 08/895,983
Process for excavating a cavity in a thin salt layer
Inventors:
Jean-Gerard Durup, Guy Boris, Yvon Charnavel
Patented Case
View Patent ↗
Granted: Sep 28, 1999
Filed: Jul 17, 1997
Inventors
Jean-Gerard Durup
Guy Boris
Yvon Charnavel
Assignee (at issue)
Gaz de France-(GDF) Service National
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.