Results 101 to 110 of about 1,054 (134)
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COUPLED TORSIONAL AND BENDING VIBRATIONS OF ACTIVELY CONTROLLED DRILLSTRINGS
Journal of Sound and Vibration, 2000Abstract The dynamics of actively controlled drillstrings is studied. The equations of motion are derived using a lumped parameter model in which the coupling between torsional and bending vibrations is considered. The model also includes the dynamics of the rotary drive system which contains the rotary table, the gearbox and an armature controlled ...
Yigit, AHMET SALİH, Christoforou, A.P.
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A Modal Approach for Chaotic Vibrations of a Drillstring
Volume 1: 22nd Biennial Conference on Mechanical Vibration and Noise, Parts A and B, 2009The purpose of this paper is to present a methodology to predict vibrations of drilllstrings for oil recovery service. The paper extends a previous model in the literature to include drill collar flexibility utilizing a modal coordinate condensed, finite element approach.
Kathira Mongkolcheep +3 more
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Method and apparatus for suppressing drillstring vibrations
The Journal of the Acoustical Society of America, 2003Apparatus and methods are described for isolating in a drillstring a device from acoustic noise by introducing between the device and a source of acoustic vibration an noise isolating apparatus, wherein the noise isolating apparatus has adjacent zones of different acoustic impedance.
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Lateral Drillstring Vibrations in Extended-Reach Wells
IADC/SPE Drilling Conference, 2000Abstract Drillstring dynamics and hole cleaning problems are some of the most important limiting factors in extended reach applications. Here, long sections of the drillstring lie on the low side of the wellbore while rotating. When the rotary speed exceeds a critical threshold the drillstring starts to "snake", sliding up and down the ...
G. Heisig, M. Neubert
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Torsional Vibration Analysis of Drillstrings in Blasthole Drilling
Volume 11: Mechanical Systems and Control, 2008Reducing vibrations in well drilling has a significant effect on improving the overall performance of the drilling process. Vibrations may affect the drilling process in different ways, i.e., reducing durability of the drillstring’s elements, reducing the rate of penetration, and deviating the drilling direction.
Omid Aminfar, Amir Khajepour
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A Review of Coupled Vibration Models of Drillstring
2018Drilling is a significant constituent part in the process of the exploration and exploitation of oil and gas. Capital expenditure spent on the drilling process make up large portion of the entire cost, and so much of the reason causing this consequence depends on the unwanted vibrations of drillstring. Unwanted vibrations may cause premature failure of
Fu-shen Ren, Bao-jin Wang
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Experimentally-Tuned Mathematical Model for Drillstring Vibrations
Volume 5: 6th International Conference on Multibody Systems, Nonlinear Dynamics, and Control, Parts A, B, and C, 2007Field experience manifests that drillstring vibration is one of the major causes for a deteriorated drilling performance. It is crucial to understand the complex vibrational mechanisms experienced by a drilling system in order to better control its functional operation and improve its performance.
Y. A. Khulief, F. A. Al-Sulaiman
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A Field Method for Controlling Drillstring Torsional Vibrations
IADC/SPE Drilling Conference, 1992Abstract Torsional vibrations are detrimental to the life of drillstring components (1,2,3,4). Although methods of controlling them have been proposed (1,3,4), their general dependence on strain gauges to measure drillstring torque make them unsuitable for the drilling environment. In this paper we describe a new, practical, system which
Prasert Sananikone +2 more
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Consequences and Relevance of Drillstring Vibration on Wellbore Stability
Proceedings of SPE/IADC Drilling Conference, 1999Abstract Historically, wellbore instability problems have been mainly attributed to the physico-chemical interaction between the rock and the drilling fluid, especially when this is a water-based fluid (WBM). However, recent studies have shown that these chemical effects may be irrelevant in comparison with other energetic events which ...
Helio Santos +2 more
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Effect of Process Damping on Longitudinal Vibrations in Drillstrings
Journal of Energy Resources Technology, 1994This paper shows the effect of process damping—caused by the interference between the cutter and the previously cut surface—on the stability of drillstrings. The method of including process damping in the calculation of the stability diagram is outlined.
M. A. Elsayed +3 more
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