Combination scratcher-centralizer for wellbore casings
US5335723A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 29, 1993 |
| Grant date | Aug 9, 1994 |
| Priority date | — |
| Expiry date | Jun 29, 2013 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B37/02
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A combination scratcher-centralizer for use in installing casing in wellbores comprising a single piece of coiled wire or rod having a first hub part for tightly engaging the casing, a radially expanded centralizer and scratcher portion forming a helical wrap of said wire and a second hub part slidable on the casing and formed by a helical wrap of said wire. The first hub part includes serrations and/or a plurality of retaining screws provided so that the first hub part may be secured to the casing in a predetermined position to allow the expanded centralizer coil or wrap portion to undergo some elastic axial excursion during its scratching and scraping operation upon installation in a wellbore. The constricted hub part may be held in a radially expanded position during installation by a retainer engageable with spaced apart portions of the wraps of the hub part.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.