Issued Patents 2003
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6668938 | Cup packer | Randolph J. Sheffield, Mark Callister Oettli, Jose Hurtado | 2003-12-30 |
| 6655461 | Straddle packer tool and method for well treating having valving and fluid bypass system | Randolph J. Sheffield, Mark Callister Oettli | 2003-12-02 |
| 6533037 | Flow-operated valve | Howard L. McGill, James M. Costley, Randolph J. Sheffield, Warren Zemlak | 2003-03-18 |