Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4888740 | Differential energy acoustic measurements of formation characteristic | Alain Brie, Kai Hsu | 1989-12-19 |
| 4870627 | Method and apparatus for detecting and evaluating borehole wall fractures | Kai Hsu, Alain Brie | 1989-09-26 |