System and method for damping vibration in a drill string using a magnetorheological damper
US9976360B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 8, 2011 |
| Grant date | May 22, 2018 |
| Priority date | — |
| Expiry date | May 9, 2033 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B44/005
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A system for damping vibration in a drill string can include a magnetorheological fluid valve assembly having a supply of a magnetorheological fluid. A remanent magnetic field is induced in the valve during operation that can be used to provide the magnetic field for operating the valve so as to eliminate the need to energize the coils except temporarily when changing the amount of damping required. The current to be supplied to the coil for inducing a desired magnetic field in the valve is determined based on the limiting hysteresis curve of the valve and the history of the magnetization of the value using a binary search methodology. The history of the magnetization of the valve is expressed as a series of sets of current and it resulting magnetization at which the current experienced a reversal compared to prior values of the current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.