A comparative review of modelling and controlling torsional vibrations and experimentation using laboratory setups

Improved drilling performance enables us to drill a high quality well at less cost per foot in the lowest time possible. Drillstring vibration is one of the limiting factors maximizing drilling performance. Also, it has become necessary for drilling oil/gas/geothermal wells in order to optimize surface drilling parameters and to reduce downhole dynamics while drilling. Operating a drillstring above or below the critical speed will definitely reduce vibrations and the probability of premature catastrophic failure of downhole components. Hence, it is necessary to carry out pre-drilling analysis as well as real time analysis of drillstring dynamics. The complexity of the drilling phenomenon makes it impractical to derive models having worldwide acceptability. Modeling the entire drillstring system and validating the results using the laboratory experiments or the field data have been the best practice. Most of the times, the parameters affecting the model's sensitivity are either unknown or insufficiently studied during the modeling which makes the study more challenging. The first part of the current review article summarizes the work carried out by the researcher in the field of modeling and controlling torsional vibrations. The second part highlights the experimental studies carried out in laboratories in order to reproduce modes of vibrations in the laboratory. Based on the past development, further efforts can be outlined in this field in order to improve the quality of reproduction of torsional vibrations in the laboratory. The present article reviews the information which needs to be considered while modeling a complete drilling system and developing a laboratory model to reproduce torsional vibrations. (C) 2013 Elsevier B.V. All rights reserved.