Differential Stuck Pipe Events – Development of Digital Best Practices for NPT Prevention

Andreas Ortner

Research output: ThesisMaster's Thesis


Stuck pipe events are operational challenges which contribute to non-productive time (NPT) and increase the associated drilling costs. It is estimated, that the costs of stuck pipe events sum up to hundreds of million US dollars annually. Approximately 25 % of the non-productive time during the drilling operation is caused by stuck pipe events. 30,5% of all those stuck pipe events are associated to be differential sticking. A drill string or bottom hole assembly can get stuck due to differential pressures if part of the string is subjected to a different pressure (formation pressure) than the hydrostatic pressure in the wellbore. However, it is claimed that differential stuck pipe can be prevented when certain best practices are applied strictly. Incorrect operational parameters, incorrect procedures, unknown formation properties, and BHA design can lead to differential stuck pipe events. Once a pipe got stuck it might take enormous effort to free the string again which increases non-productive time, increases the drilling costs and might cause safety issues. There exist several best practices for avoiding differential stuck pipe and for relieving the pipe once it occurred. Detecting an upcoming stuck pipe event relies on the experience of the operating personnel and their interpretation of the drilling parameters. The aim of the thesis is to use a state-of-the-art drilling simulator to create realistic training cases based on best practices. Students and professionals can train on this simulator to improve their skills. Further, the reduction of NPT due to training should reduce drilling costs and increase safety.
Translated title of the contributionFestwerden des Bohrstrangs aufgrund von Differenzdrücken - Entwicklung Digitaler Best-Practice Lösungswege für die Verhinderung von Unproduktiver Zeit
Original languageEnglish
Awarding Institution
  • Montanuniversität
  • Thonhauser, Gerhard, Supervisor (internal)
  • Lettner, Anton, Co-Supervisor (internal)
Award date22 Sept 2020
Publication statusPublished - 2020

Bibliographical note

embargoed until 07-05-2025


  • Differential sticking
  • eDrilling
  • Drilling simulator
  • NPT

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