Nonlinearity and spectrum analysis of drill strings with component mass unbalance

F. Abdul Majeed, H. Karki, Y. Abdel Magid, Mansour Karkoub

Research output: Contribution to journalArticle

1 Citation (Scopus)


This paper analyses the non linear properties exhibited by a drill string system under various un balanced mass conditions. The drill string is affected by continuous friction in the form of drill bit and well bore hole interactions. This paper proves the origin of limit cycling and increase of non linearity with increase in speed of the drilling in the presence of friction. The spectrum of the frequency response is also studied to detect the presence of vibration abnormalities arising during the drilling process.

Original languageEnglish
Pages (from-to)459-462
Number of pages4
JournalWorld Academy of Science, Engineering and Technology
Publication statusPublished - Jan 2011



  • Drill strings
  • Nonlinear
  • Spectrum analysis
  • Unbalanced mass

ASJC Scopus subject areas

  • Engineering(all)

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