Issued Patents 1989
Showing 1–5 of 5 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4886113 | Positive indication shear ring | Colby M. Ross, James D. Hendrickson | 1989-12-12 |
| 4846281 | Dual flapper valve assembly | Sammy R. Clary, Richard M. Sproul | 1989-07-11 |
| 4840229 | Multiple position service seal unit with positive position indicating means | Lewis D. Proctor, Colby M. Ross, Brian P. Manzi | 1989-06-20 |
| 4832129 | Multi-position tool and method for running and setting a packer | Richard M. Sproul, Carter R. Young, John B. Wilkie, Jr. | 1989-05-23 |
| 4813481 | Expendable flapper valve | Richard M. Sproul, Richard L. Grant, Kennedy J. Brown | 1989-03-21 |