Directional drilling assembly and method
US6213226A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 1997 |
| Grant date | Apr 10, 2001 |
| Priority date | — |
| Expiry date | Dec 4, 2017 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B17/1014
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The drilling assembly includes an eccentric adjustable diameter blade stabilizer having a housing with a fixed stabilizer blade and a pair of adjustable stabilizer blades. The adjustable stabilizer blades are housed within openings in the stabilizer housing and have inclined surfaces which engage ramps on the housing for camming the blades radially upon their movement axially. The adjustable blades are operatively connected to an extender piston on one end for extending the blades and a return spring at the other end for contracting the blades. The eccentric stabilizer also includes one or more flow tubes through which drilling fluids pass that apply a differential pressure across the stabilizer housing to actuate the extender pistons to move the adjustable stabilizer blades axially upstream to their extended position. The eccentric stabilizer is mounted on a bi-center bit which has an eccentric reamer section and a pilot bit. In the contracted position, the areas of contact between the eccentric stabilizer and the borehole form a contact axis which is coincident with the pass through axis of the bi-center bit as the drilling assembly passes through the existing cased borehole. In …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.