Retractable slip assembly
US4813486A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1987 |
| Grant date | Mar 21, 1989 |
| Priority date | — |
| Expiry date | Sep 23, 2007 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B23/01
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A retractable slip assembly for downhole oil tools such as packers and anchors which permits retrieval of the tool with a minimum of force and without damaging the casing or tool. The slip assembly includes a plurality of slip elements adapted to engage a setting cone which moves the slips outwardly into engagement with the casing wall. The individual slip elements travel within slip windows formed in an outer sleeve. In addition to guiding the slips, the slip windows facilitate retraction of the slip elements. In order to reduce the force necessary to release the slip assemblies, the engaging edges of the slip elements and the slip windows are provided with a cooperating angle corresponding to the slope of the setting cone and slip underside. The reduced force necessary to retract the slips allows the use of upper and lower slip assemblies in conjunction with a packer assembly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.