... in a wellbore of 3D profile. The model suggests possible contact/lift-off of drill pipes with/from the wellbore wall. The interaction of lateral, torsional, and axial vibrations is taken into account. The relation between the normal component of contact force and the deformation of the wellbore wall is taken...

... ( 2007, KHIMERA04, Version 1.1, Motorola Inc ; Novoselov et al., 2002, “CHIMERA: A Software Tool for Reaction Rate Calculations and Kinetics and Thermodynamics Analysis,” J. Comput. Chem., 23, pp. 1375–1389 ), contributions from energies, harmonic vibrational frequencies, and moments of inertia were...

... the forces developed at the bit-rock interface and the modes of vibration of the drill string. Although existing testing facilities are adequate for characterizing bit performance in various formations and operating conditions, they lack the necessary drill string attributes to characterize the interaction...

...Don W. Allen; Dean L. Henning; Li Lee Current tank tests have been performed on two equal-diameter, flexible cylinders in tandem with various end spacings or separation distances. While the cylinders experienced transverse vortex-induced vibration in only the first mode, the test Reynolds numbers...

...M. A. Elsayed Drill strings are used in oil and gas production as well as geothermal wells. They experience destructive vibrations, many of which are highly dependent on drill string modes. In this paper, we show that the lowest frequency modes are not necessarily the most critical and we delineate...

...Ahmet S. Yigit; Andreas P. Christoforou 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...

...Jason R. Graves; Don W. Dareing This paper presents a direct method for determining natural frequencies of lateral modes of vibration for marine risers in deep water. This method applies to marine risers that are vertical, relatively straight, and attached at both ends. The method is particularly...

...Joa˜o Carlos R. Pla´cido; He´lio M. R. Santos; Yadira Diaz Galeano Wellbore instability can be attributed to several causes. The ones thought to be most important include: chemical interaction with the drilling fluid, high tectonic stresses, and insufficient mud weight. Drillstring vibration...

...Pushkar N. Jogi; John D. Macpherson; Michael Neubert Vibrations generated in a drill string while drilling generally lead to a reduction in drilling efficiency and often cause premature failure of drill string components and bit damage. It is also known that lateral vibrations, in particular...

...Robert R. Reynolds, Assistant Professor, Mem. ASME; Jack H. Cole, Professor, Mem. ASME; Zhen Yuan, Formerly, Graduate Research Assistant The influence of geometry on the pressure field within the confined, water-filled annulus between a central, vibrating cylinder and an outer, rigid enclosure...

.... Wolf, S. F., Zacksenhouse, M., and Arian, A., 1985, “Field Measurement of Downhole Drillstring Vibrations,” 60st Annual Technical Conference and Exhibition of the SPE, Las Vegas, NV , Paper SPE 14675. Aldred, W. D., and Sheppard M. C., 1992, “Drillstring Vibrations: A New Generation Mechanism...