Issued Patents All Time
Showing 126–135 of 135 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5495174 | Method and apparatus for detecting boundary stratum and adjusting the direction of drilling to maintain the drill string within a bed of interest | M. Vikram Rao | 1996-02-27 |
| 5389881 | Well logging method and apparatus involving electromagnetic wave propagation providing variable depth of investigation by combining phase angle and amplitude attenuation | Michael S. Bittar | 1995-02-14 |
| 5330016 | Drill bit and other downhole tools having electro-negative surfaces and sacrificial anodes to reduce mud balling | William C. Paske, Ronald D. Ormsby | 1994-07-19 |
| 5278507 | Well logging method and apparatus providing multiple depth of investigation using multiple transmitters and single receiver pair having depth of investigation independent of formation resistivity | Roger P. Bartel, M. Vikram Rao | 1994-01-11 |
| 4980642 | Detection of influx of fluids invading a borehole | — | 1990-12-25 |
| 4940943 | Method and apparatus for optimizing the reception pattern of the antenna of a propagating electromagnetic wave logging tool | Roger P. Bartel | 1990-07-10 |
| 4791797 | Density neutron self-consistent caliper | William C. Paske, Ray A. Roeder | 1988-12-20 |
| 4730281 | Data processing filtering method and apparatus | Richard A. Kester | 1988-03-08 |
| 4665511 | System for acoustic caliper measurements | James R. Birchak | 1987-05-12 |
| 4590593 | Electronic noise filtering system | — | 1986-05-20 |