Retrieval tool for back pressure valve and tree test plug
US5782297A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 19, 1996 |
| Grant date | Jul 21, 1998 |
| Priority date | — |
| Expiry date | Aug 19, 2016 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B23/00
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A retrieval tool for retrieving a back pressure valve and tree test plug (generally, a check valve) has a spear formed as a solid ring at the bottom with free fingers extending upward. The fingers are resilient and have protrusions adapted to engage a retrieval groove in the check valve. A wedge ring is provided on the tool body to positively lock the fingers in radially outward engagement with the retrieval groove. The wedge ring is fixed to the body by a shear pin so that upon a predetermined axial force the pin shears and releases the wedge ring allowing withdrawal of the tool assembly, if the check valve is stuck in a tubing hanger or coupling.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.