Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4858691 | Gravel packing apparatus and method | William T. Ilfrey, Elmer R. Peterson, William Nickolas Moran | 1989-08-22 |
| 4856591 | Method and apparatus for completing a non-vertical portion of a subterranean well bore | Joseph F. Donovan, John V. Salerni, Elmer R. Peterson, John B. Weirich | 1989-08-15 |