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Title: System and method for damping vibration in a drill string using a magnetorheological damper

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.
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Issue Date:
OSTI Identifier:
APS Technology, Inc. (Wallingford, CT) NETL
Patent Number(s):
Application Number:
Contract Number:
Resource Relation:
Patent File Date: 2011 Sep 08
Research Org:
National Energy Technology Laboratory, Pittsburgh, PA, and Morgantown, WV (United States)
Sponsoring Org:
Country of Publication:
United States