Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4880056 | Hydraulically activated firing head for well perforating guns | John A. Nelson | 1989-11-14 |
| 4830120 | Methods and apparatus for perforating a deviated casing in a subterranean well | — | 1989-05-16 |
| 4817718 | Hydraulically activated firing head for well perforating guns | John A. Nelson | 1989-04-04 |