Issued Patents 1997
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5639715 | Aqueous based drilling fluid additive and composition | — | 1997-06-17 |
| 5635458 | Water-based drilling fluids for reduction of water adsorption and hydration of argillaceous rocks | Li-Jein Lee | 1997-06-03 |