Numerical wellbore stability analysis using discrete element models

E. Jamshidi, M. Amani

Research output: Contribution to journalArticle

2 Citations (Scopus)


Wellbore instability, which is considered as failure of borehole wall, is a complex and time-consuming analysis. Numerous factors such as well path, rock mechanical properties, in situ stress regimes, pore pressure, mud weight, bedding planes, and fractures play a role in borehole instability. Many wellbore stability analyses methods consider only a few of mentioned parameters and majority of them are based on continuum mechanics. However, most of the methods presented for wellbore stability analyses do not consider the impact of fractures. In the present work discrete element models (DEM) are used for numerical wellbore stability analysis of horizontal wells, while the presence of fractures is considered. In this study the effect of mud cyclic loading, hole length, stress regimes, and fluid pressures in fracture plane are examined. The results of analyses showed that direction of minimum horizontal stress is the optimum drilling direction. To evaluate the effects of mud cyclic loadings and open hole lengths, two other models are also considered. These models reveal that mud cyclic loading reduces the stability of borehole. Moreover, it was concluded that mud weight must be increased as open hole length increases and it should not exceed the upper mud weight limit.

Original languageEnglish
Pages (from-to)974-982
Number of pages9
JournalPetroleum Science and Technology
Issue number8
Publication statusPublished - 18 Apr 2014
Externally publishedYes



  • cyclic loadings
  • discrete element models
  • fractures
  • wellbore instability

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Fuel Technology
  • Energy Engineering and Power Technology
  • Geotechnical Engineering and Engineering Geology

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