Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7464758 | Model HCCV hydrostatic closed circulation valve | Joseph C. H. Yeo, Keith E. Lewis, Christopher L. Weaver | 2008-12-16 |
| 7373980 | Mono-trip cement thru completion | Keith E. Lewis, Joseph C. H. Yeo, Jim H. Kritzler, Walter Chapman, James Holt | 2008-05-20 |
| 7069992 | Mono-trip cement thru completion | Keith E. Lewis, Joseph C. H. Yeo, Jim H. Kritzler, Walter Chapman, James Holt | 2006-07-04 |
| 7063152 | Model HCCV hydrostatic closed circulation valve | Joseph C. H. Yeo, Keith E. Lewis, Christopher L. Weaver | 2006-06-20 |