Results 91 to 100 of about 1,054 (134)
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Investigation on random vibration of a drillstring
Journal of Sound and Vibration, 2017Abstract This paper investigates the axial-torsional coupled vibration of a drill-string under combined deterministic and random excitations. Finite element method (FEM) is used to model the system. The random excitation at the bit-rock interaction, which is considered in the bit axial direction, is treated as Gaussian white noise.
Hongyuan Qiu +3 more
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Self-Excited Vibrations in Drillstrings
SPE Annual Technical Conference and Exhibition, 1987Abstract Vibrations created by drag bits can cause premature failure of drillstring components and fracture cutters. Unfortunately, there has been no theory that adequately explains how drag bits excite drillstrings. Our paper shows that these vibrations are self excited by the interaction of drillstring, bit, and formation. Results show
C.A. Zamudio, J.L. Tlusty, D.W. Dareing
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New Mechanism in Drillstring Vibration
Offshore Technology Conference, 1990ABSTRACT In deep well drilling for oil and gas, it has been observed and recorded that severe vibrations build up and die down periodically. The beating phenomenon is a frequent occurrence, particularly, during all startup tests and on most of those exhibiting the low frequency torsional vibration.
Yao Qun Lin, Yu Hwa Wang
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Stabilization of torsional vibration in oilwell drillstring system
European Journal of Control, 2017zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Toumi, Samir +3 more
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COUPLED AXIAL AND TRANSVERSE VIBRATIONS OF OILWELL DRILLSTRINGS
Journal of Sound and Vibration, 1996Abstract Transverse vibrations of drillstrings caused by axial loading and impact with the wellbore wall is studied. The drillstring is modeled as a slender beam with a simply-supported lower part. The Assumed Modes Method is used to obtain the governing equations of motion.
Christoforou, A.P., Yigit, AHMET SALİH
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Drillstring Vibrations and Wellbore Quality: Where Drillstring Design Meets Geomechanics
Abu Dhabi International Petroleum Exhibition & Conference, 2018Abstract Wellbore quality might not always be the top priority from a drilling perspective due to the misconception that quality comes at the expense of drilling efficiency. This is indeed a misconception since a compromised wellbore quality, which can be defined as non-uniform wellbore shape due to the presence of enlargements and tight
Hussain AlBahrani, Abdullah Al-Yami
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ANALYSIS OF DRILLSTRING VIBRATIONS USING ACTIVE CIRCUITS
2006 GSW Proceedings, 2022Comment: 18 ...
Chaitanya Kancharla +2 more
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Field Measurements of Downhole Drillstring Vibrations
SPE Annual Technical Conference and Exhibition, 1985ABSTRACT NL's Wire Telemetry System was used in the field to provide high-data-rate measurements of downhole forces, accelerations, pressures and formation properties. This paper describes, and briefly discusses, downhole longitudinal and lateral vibrations and their correlation with formation characteristics.
S.F. Wolf, M. Zacksenhouse, A. Arian
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Control of Stick-Slip Vibration in Drillstrings with Multiple Frequencies
2020 American Control Conference (ACC), 2020Torsional vibration is a common phenomenon, known as stick-slip in oil-well drilling, that causes poor drilling performance, downhole tool failure, and bit wear. It is observed that stick-slip vibration- generally occur at multiple frequencies. To help mitigate torsional vibration, a dynamic model of drillstring is first studied where analytical ...
Zhijie Sun, Sujian Huang
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Predictive control of torsional drillstring vibrations
2016 20th International Conference on System Theory, Control and Computing (ICSTCC), 2016In this paper, the control problem of torsional vibrations occurring along a rotary drillstring system is approached. This task is performed using a predictive control strategy, based on a discrete-time model of the system, taking into account the constraint on control input.
Andreea Soimu, Florin Stinga
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