?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F246%2F&rft.title=Underreamer+mechanics&rft.creator=Jones%2C+Marvin&rft.creator=Barton%2C+David&rft.creator=Hall%2C+Cameron&rft.creator=Coskun%2C+Erhan&rft.creator=Lacey%2C+Andrew&rft.creator=Lorenz%2C+Maike&rft.creator=Maringer%2C+Johannes&rft.creator=Please%2C+Colin&rft.creator=Richardson%2C+Giles&rft.subject=Energy+and+utilities&rft.description=In+the+oil+and+gas+industry%2C+an+underreamer+is+a+tool+used+to+extend+and+enlarge+the+diameter+of+a+previously-drilled+bore.+The+problem+proposed+to+the+Study+Group+is+to+obtain+appropriate+mathematical+models+of+underreamer+dynamics%2C+in+forms+that+will+lead+to+feasible+computation.+The+modes+of+dynamics+of+interest+are+torsional%2C+lateral+and+axial.%0D%0A%0D%0AThis+report+describes+some+initial+models%2C+two+of+which+are+developed+in+more+detail%3A+one+for+the+propagation+of+torsional+waves+along+the+drill+string+and+their+reflection+from+contact+points+with+the+well+bore%3B+and+one+for+the+dynamic+coupling+between+the+underreamer+and+the+drill+bit+during+drilling.&rft.date=2009&rft.type=Study+Group+Report&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F246%2F1%2FSmartReamer-Underreamer.pdf&rft.identifier=++Jones%2C+Marvin+and+Barton%2C+David+and+Hall%2C+Cameron+and+Coskun%2C+Erhan+and+Lacey%2C+Andrew+and+Lorenz%2C+Maike+and+Maringer%2C+Johannes+and+Please%2C+Colin+and+Richardson%2C+Giles++(2009)+Underreamer+mechanics.++%5BStudy+Group+Report%5D+++++