Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5204320 | Drilling mud additive comprising ferrous sulfate and poly(N-vinyl-2-pyrrolidone/sodium 2-acrylamido-2-methylpropane sulfonate) | Bharat B. Patel | 1993-04-20 |
| 4876030 | Organophilic clay suspension medium | Robert M. Parlman, Wayne S. Stewart | 1989-10-24 |
| 4743383 | Drilling fluid additives for use in hard brine environments | Wayne S. Stewart, John M. Elsen, Billy L. Swanson | 1988-05-10 |
| 4482848 | Controllable power source | John C. W. Heal | 1984-11-13 |