The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
May. 22, 2018

Filed:

Nov. 01, 2013
Applicants:

Andreas Hohl, Hannover, DE;

Mathias Tergeist, Celle, DE;

Hatem Oueslati, Hannover, DE;

Christian Herbig, Celle, DE;

Jayesh J. Jain, The Woodlands, TX (US);

Hanno Reckmann, Nienhagen, DE;

Lance A. Endres, Spring, TX (US);

Inventors:

Andreas Hohl, Hannover, DE;

Mathias Tergeist, Celle, DE;

Hatem Oueslati, Hannover, DE;

Christian Herbig, Celle, DE;

Jayesh J. Jain, The Woodlands, TX (US);

Hanno Reckmann, Nienhagen, DE;

Lance A. Endres, Spring, TX (US);

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B 44/02 (2006.01); G06F 17/50 (2006.01);
U.S. Cl.
CPC ...
E21B 44/02 (2013.01); G06F 17/5086 (2013.01);
Abstract

A method for reducing drill tubular vibrations includes: constructing a mathematical model the drill tubular having mass distribution, material stiffness and material damping; constructing an equation of motion of the drill tubular in one of a time domain and frequency domain; transforming the equation of motion into a modal domain equation of motion to provide a mode shape of the drill tubular at an eigenfrequency, the mode shape providing an amplitude at a position along the drill tubular; comparing the amplitude at the position along the drill tubular to a threshold amplitude value; modifying at least one of the mass distribution, material stiffness and material damping if the amplitude exceeds the threshold value; and iterating the above step until at least one of the amplitude of the latest mode shape at the position is less than or equal to the threshold amplitude value and a predetermined constraint limits the modifying.


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