Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 10087726 | System and method for rotating casing string | Charles Chapman | 2018-10-02 |
| 9605503 | System and method for rotating casing string | Charles Chapman | 2017-03-28 |
| 7017682 | Drill string shutoff valve | Kwong-Onn Chan, Behrooz Movaffagh, Xiaoping He | 2006-03-28 |
| 6918452 | Drill string shutoff valve | Kwong-Onn Chan, Behrooz Movaffagh | 2005-07-19 |