Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 8496064 | System and method for engaging completions in a wellbore | Michael Hui Du, Gary L. Rytlewski | 2013-07-30 |
| 5611398 | Two-piece drilling flange | Rex E. Duhn | 1997-03-18 |
| 4974676 | Ground subsiding wellhead | Rex E. Duhn, Jay C. Duhn | 1990-12-04 |