Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4325438 | Lengthening drill string containing an instrument | — | 1982-04-20 |
| 4181014 | Remote well signalling apparatus and methods | Raymond W. Teys, Richard A. Johnson | 1980-01-01 |