Downhole adjustable stabilizer
US5181576A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 1991 |
| Grant date | Jan 26, 1993 |
| Priority date | — |
| Expiry date | Jul 30, 2011 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B17/1014
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
In accordance with illustrative embodiments of this invention, a downhole adjustable stabilizer includes a sleeve having outwardly extending blades and mounted for limited rotation on a mandrel, vertically aligned sets of radially movable buttons mounted in bores in the blades, and longitudinal flats on the outer periphery of the mandrel that when radially aligned with the respective sets of buttons allows them to shift inward to positions where the stabilizer becomes undergage and can be tilted in the borehole. Some spring loaded buttons drag against the borehole wall to provide frictional restraint against rotation of the housing. The blades can each have an inclined side surface that causes the sleeve to be rotated to its position relative to the mandrel where the sets of buttons are retracted as the stabilizer slides downward in the borehole. In another embodiment a hydraulic delay is provided which restrains relative rotation in the direction which cause the buttons to extend to their full gauge diameter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.