Abstract
Under certain conditions of deep drilling with PDC bits, violent stick-slip torsional vibrations take place in the drilling strueture. In the classical approach used to analyze this problem, it is assumed that stick-slip events arc triggered by a bit-rock interaction law, characterized by a decrease of the torque with angular velocity (which is formally equivalent to a decreasing apparent friction coefficient with angular velocity). Based on laboratory data, we argue that this relationship is not an intrinsic characteristic of the bit-rock interaction. We then elaborate on the coupling between vertical and torsional vibrations at the bit as a possible primary cause of stick-slip. Preliminary results obtained with this model indicate that such coupling is sufficient to generate stick-slip without the need to assume a decreasing friction coefficient.
Original language | English (US) |
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Title of host publication | 4th North American Rock Mechanics Symposium, NARMS 2000 |
Publisher | American Rock Mechanics Association (ARMA) |
Pages | 33-40 |
Number of pages | 8 |
ISBN (Print) | 9058091554, 9789058091550 |
State | Published - 2000 |
Event | 4th North American Rock Mechanics Symposium, NARMS 2000 - Seattle, United States Duration: Jul 31 2000 → Aug 3 2000 |
Publication series
Name | 4th North American Rock Mechanics Symposium, NARMS 2000 |
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Other
Other | 4th North American Rock Mechanics Symposium, NARMS 2000 |
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Country/Territory | United States |
City | Seattle |
Period | 7/31/00 → 8/3/00 |
Bibliographical note
Publisher Copyright:© 2000 Balkema, Rotterdam.