Self-adjusting centralizer
US5348091A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 16, 1993 |
| Grant date | Sep 20, 1994 |
| Priority date | — |
| Expiry date | Aug 16, 2013 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/01
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An oil-field tool for use in combination with a MWD tool, for deployment and retrieval of a MWD tool through a drill string, and, for rigid continuously self-adjusting, centralization of the MWD tool during drilling, includes: housing having a tapering nose; slidable shaft having a flared portion; extendable fingers pivotably attached to the slidable shaft; means for releasable attachment to a workstring; and, means for attachment to a MWD tool. Typically, the housing of the invention is attached to a MWD tool while at the surface and the combined apparatus is lowered through the drill string by wireline releasably attached to the slidable shaft. During lowering, the weight of the housing and MWD tool extends the slidable shaft, positioning the extendable fingers above the tapering nose of the housing, thereby retracting the fingers. When the MWD tool lodges downhole, the slidable shaft moves downward, causing the fingers to override the tapering nose of the housing and extend the fingers outward against the drill pipe. During drilling operations mud flowing through the drill pipe acts downwardly on flared portion of the slidable shaft inducing more forceable extension of the finge…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.