Deep drilling is used to develop oil, gas and geothermal energy resources. A drill string is set in rotation by a drilling rig, at the end of which is a bit that breaks the rock. The cuttings are removed by a drilling fluid that also stabilizes the borehole. Given its length of several kilometers, a deep drill string is a very flexible structure in which axial, lateral, and torsional vibrations occur during the drilling process. These vibrations, which can be caused by bit-rock interactions, imbalances or shocks, not only reduce the efficiency of the drilling process, but can also cause damage to the drill string components, such as cracking or even failure. The goal is to reduce the effects of vibration to ensure safe and fast deep drilling.
The goal of this project, which is being carried out in cooperation with Baker Hughes INTEQ GmbH, is to characterize and understand the vibrations that occur. To this end, measurement data recorded during the drilling process are evaluated and compared with drill string models that represent drill string dynamics and phenomena such as whirling and shocks. From this, load profiles can be derived for the drill string and its components, allowing conclusions to be drawn about reliability and service life. Since measurement data, parameters and models are all subject to uncertainties, uncertainty quantification methods are used to determine a distribution of parameters and to analyze the sensitivity of individual parameters. The aim is to increase the efficiency and safety of the drilling process in the long term.
