Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4816674 | Determining a formation porosity from neutron logging information | Darwin V. Ellis, Charles Flaum | 1989-03-28 |
| 4810876 | Logging apparatus and method for determining absolute elemental concentrations of subsurface formations | Peter Wraight, Russel C. Hertzog, Darwin V. Ellis, Jeffrey S. Schweitzer, James A. Grau | 1989-03-07 |