Downhole apparatus and method for torsional oscillation abatement
US9650834B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 2016 |
| Grant date | May 16, 2017 |
| Priority date | — |
| Expiry date | Sep 9, 2036 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/024
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The rotary steerable drilling tool and system described herein combines both point-the-bit and push-the-bit techniques to actively change the direction of the borehole trajectory. In this system, the deflection of the drill bit is limited to a single degree of freedom relative to a coordinate system that is fixed to and rotates with the rotary steerable drilling tool, resulting in a simplified attachment of the bit assembly and bias unit mechanics. Further, steering of the well is accomplished by dynamically controlling the spatial phase and amplitude of the coherent symmetrical bidirectional reciprocating deflections of the drill bit relative to a fixed terrestrial datum as the tool is rotating, simultaneously pointing and pushing the bit. Alternatively, when not being used to change the direction of the borehole trajectory, the rotary steerable drilling tool apparatus can be used to mitigate or abate the stick-slip tendencies of the drill string by dithering the bit using spatially variable asynchronous symmetrical bidirectional reciprocating deflections of the drill bit at frequencies that are different from the rotational frequency of the bottom hole assembly. When neither stee…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.