Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 9187976 | Apparatus and methods for releasing drilling rig and blowout preventer (BOP) prior to cement bonding | Henry He, Huahui Wang | 2015-11-17 |
| 7090033 | Drill string shutoff valve | Kwong-Onn Chan, Xiaoping He | 2006-08-15 |
| 7017682 | Drill string shutoff valve | Kwong-Onn Chan, Xiaoping He, Loren P. Boisvert | 2006-03-28 |
| 6918452 | Drill string shutoff valve | Kwong-Onn Chan, Loren P. Boisvert | 2005-07-19 |