Issued Patents All Time
Showing 26–34 of 34 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5180007 | Low pressure responsive downhold tool with hydraulic lockout | Paul D. Ringgenberg, Roger L. Schultz | 1993-01-19 |
| 5149984 | Electric power supply for use downhole | Roger L. Schultz, Neal G. Skinner, William L. Bohan, Allen R. Young | 1992-09-22 |
| 5101907 | Differential actuating system for downhole tools | Roger L. Schultz, Neal G. Skinner | 1992-04-07 |
| 5058674 | Wellbore fluid sampler and method | Roger L. Schultz, H. Kent Beck | 1991-10-22 |
| 4903775 | Well surging method and apparatus with mechanical actuating backup | — | 1990-02-27 |
| 4665991 | Downhole tool with gas energized compressible liquid spring | — | 1987-05-19 |
| 4664196 | Downhole tool with compressible liquid spring chamber | — | 1987-05-12 |
| 4646838 | Low pressure responsive tester valve with spring retaining means | — | 1987-03-03 |
| 4573535 | Sleeve-type low pressure responsive APR tester valve | — | 1986-03-04 |