Drillstring vibrations and in particular stick-slip and bit-bounce are detrimental to oil-well drilling operations. Controlling these vibrations is essential because they may cause equipment failures and damage to the oil-well. A simple model that adequately captures the dynamics is used to simulate the effects of varying operating conditions on stick-slip and bit-bounce interactions. It is shown that the conditions at the bit/formation interface, such as bit speed and formation stiffness, are major factors in shaping the dynamic response. Due to the varying and uncertain nature of these conditions, simple operational guidelines or active rotary table control strategies are not sufficient to eliminate both stick-slip and bit-bounce. It is demonstrated that an additional active controller for the axial motion can be effective in suppressing both stick-slip and bit-bounce. It is anticipated that if the proposed approach is implemented, smooth drilling will be possible for a wide range of conditions.
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December 2006
Article Contents
Research Papers
Stick-Slip and Bit-Bounce Interaction in Oil-Well Drillstrings
Ahmet S. Yigit
Ahmet S. Yigit is the Director of the Office of Academic Assessment at the College of Engineering and Petroleum, Kuwait University. He is also a Professor at the Department of Mechanical Engineering. He received a Ph.D. in Mechanical Engineering from the University of Michigan. His research interests include dynamics and control of rigid and flexible systems, vibrations of machinery, drilling dynamics, impact dynamics, and engineering education.
Ahmet S. Yigit
Department of Mechanical Engineering,
yigit@kuc01.kuniv.edu.kw
Kuwait University
, P.O. Box 5969, Safat 13060, Kuwait
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Andreas P. Christoforou
Andreas P. Christoforou is a Professor of Mechanical Engineering at Kuwait University. He received his Ph.D. in Mechanical Engineering from the University of Utah. His research interests are in failure prediction, impact dynamics, and damage of composite materials and structures. In his research work he has utilized experimental, analytical, and numerical methods. He has also been active in engineering education research, specifically in the assessment of educational objectives and outcomes.
Andreas P. Christoforou
Department of Mechanical Engineering,
Kuwait University
, P.O. Box 5969, Safat 13060, Kuwait
Search for other works by this author on:
Ahmet S. Yigit
Ahmet S. Yigit is the Director of the Office of Academic Assessment at the College of Engineering and Petroleum, Kuwait University. He is also a Professor at the Department of Mechanical Engineering. He received a Ph.D. in Mechanical Engineering from the University of Michigan. His research interests include dynamics and control of rigid and flexible systems, vibrations of machinery, drilling dynamics, impact dynamics, and engineering education.
Andreas P. Christoforou
Andreas P. Christoforou is a Professor of Mechanical Engineering at Kuwait University. He received his Ph.D. in Mechanical Engineering from the University of Utah. His research interests are in failure prediction, impact dynamics, and damage of composite materials and structures. In his research work he has utilized experimental, analytical, and numerical methods. He has also been active in engineering education research, specifically in the assessment of educational objectives and outcomes.
J. Energy Resour. Technol. Dec 2006, 128(4): 268-274 (7 pages)
Published Online: February 19, 2006
Article history
Received:
June 5, 2005
Revised:
February 19, 2006
