Inter-mode patterns in bundengan string vibrations

2021 ◽  
Vol 149 (4) ◽  
pp. A98-A98
Author(s):  
Gea O. Parikesit
Keyword(s):  
String Vibrations

Drill String Vibrations Due to Intermittent Contact of Bit Teeth

1963 ◽  
Vol 85 (2) ◽  
pp. 187-194 ◽  
Author(s):  
P. R. Paslay ◽  
D. B. Bogy
Keyword(s):  
Experimental Data ◽  
Penetration Rate ◽  
Drill String ◽  
String Vibrations ◽  
Order Of Magnitude ◽  
Intermittent Contact ◽  
Maximum Penetration ◽  
Sufficient Magnitude ◽  
Force Excitation ◽  
Practical Measurement

An analysis of the longitudinal forces and the resulting longitudinal motions of an idealized drill string is presented. The only external force excitation considered occurs at the bit and is due to the intermittent contact of the teeth with the bottom of the hole. Attention has been restricted to the following two salient possibilities: 1 - Excitation at the bit may develop oscillating forces at the bit with amplitudes of the same order of magnitude as those of the bit load. 2 - Appreciable bit load variation may be detected by instruments which measure the motion of the drill string near its top. The first possibility is important if maximum penetration rate is to be achieved, and the second possibility is important in implementing practical measurement of the phenomenon. From the results of the specific example considered in this report, it is concluded that possibilities 1 and 2 may occur in sufficient magnitude to be influential, but experimental data on the actual bit motion and the damping will be required to evaluate the effect. The analysis is presented in such form that the influence of the various parts of the system can easily be evaluated.

The Study on Harmonic Vibration of Drill String in Horizontal Well

2010 ◽  
Vol 139-141 ◽  
pp. 2397-2400
Author(s):  
Chun Jie Han ◽  
Tie Yan
Keyword(s):  
Horizontal Well ◽  
Drill String ◽  
Harmonic Vibration ◽  
Well Drilling ◽  
Harmonic Vibrations ◽  
String Vibrations ◽  
Resonance Frequencies ◽  
Set Up ◽  
Drill Tool ◽  
Modal Vibration

During exploitation of horizontal well drilling engineering, the problem of drill string failure is very serious, there are many reasons, and drill string vibrations are main reasons. In this paper drill string of horizontal well is object being studied. The models about various vibrations are set up. The vibration rule of drill string is obtained under different situation; the axial and lateral frequency of drill string vibration in free state is studied. The analysis of modal vibration of drill string is the basis of the analysis of harmonic vibration of drill string. The harmonic vibrations rules of drill string of horizontal well are studied. All sorts of resonance frequencies are obtained practicability. This study can prove basic method for optimizing drill tool of horizontal well and reducing drill string failure.

scholarly journals String vibrations in hammered dulcimers

1994 ◽  
Vol 95 (5) ◽  
pp. 3002-3002
Author(s):  
David R. Peterson
Keyword(s):  
String Vibrations
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