TY - GEN
T1 - Bit-bounce and stick-slip in drill-string dynamics
AU - Nandakumar, K.
AU - Wiercigroch, Marian
AU - Pearson, Chris
N1 - We thank the BG Group for financial assistance to carry out a research project on the modeling of drill-string dynamics of which this work forms a part. KN thanks Pankaj Wahi for technical discussions that gave initial directions to this work.
PY - 2013/1/1
Y1 - 2013/1/1
N2 - A recently proposed two degrees-of-freedom model for axial and torsional vibrations of drill-string elsewhere is here revisited. Themodel involves statedependent time delay, with discontinuous cutting and friction force nonlinearities. The original model is, here, enhanced by introducing axial and torsional damping, and axial stiffness. Stability analysis, which is relatively recent for systems with state-dependent delays, is conducted on the enhanced model. For representative parameter values, it is concluded from the analysis that the original model (with no damping) had no stable operating regime, while the enhanced model possesses some practically relevant stable operating regime. The steady drilling state corresponding to the enhancedmodel is, however, still unstable for a major portion of the operating regime leading to stick-slip and bit-bounce situations.
AB - A recently proposed two degrees-of-freedom model for axial and torsional vibrations of drill-string elsewhere is here revisited. Themodel involves statedependent time delay, with discontinuous cutting and friction force nonlinearities. The original model is, here, enhanced by introducing axial and torsional damping, and axial stiffness. Stability analysis, which is relatively recent for systems with state-dependent delays, is conducted on the enhanced model. For representative parameter values, it is concluded from the analysis that the original model (with no damping) had no stable operating regime, while the enhanced model possesses some practically relevant stable operating regime. The steady drilling state corresponding to the enhancedmodel is, however, still unstable for a major portion of the operating regime leading to stick-slip and bit-bounce situations.
KW - Axial and torsional damping
KW - Delay differential equations
KW - Drill-string dynamics
KW - Stick-slip
UR - http://www.scopus.com/inward/record.url?scp=85032670430&partnerID=8YFLogxK
U2 - 10.1007/978-94-007-5742-4_25
DO - 10.1007/978-94-007-5742-4_25
M3 - Published conference contribution
AN - SCOPUS:85032670430
SN - 9789400757417
SN - 9789400794511
T3 - IUTAM Bookseries
SP - 323
EP - 335
BT - IUTAM Symposium on Nonlinear Dynamics for Advanced Technologies and Engineering Design
A2 - Wiercigroch, Marian
A2 - Rega, Giuseppe
PB - Springer
T2 - IUTAM Symposium on Nonlinear Dynamics for Advanced Technologies and Engineering Design, 2010
Y2 - 27 July 2010 through 30 July 2010
ER -