In response to the failure problem of axial-torsional coupling vibration of drill string in oil & gas wells, an axial-torsional coupling nonlinear vibration model of drill string is established using the finite element method, which can effectively simulate the coupling vibration of actual wellbore drill string multi-body systems and the real-time rock breaking effect. Moreover, the correctness and effectiveness of the theoretical model verified by a similar experiment of tubing vibration. Finally, the influences of feed rate and rotary drilling speed on the nonlinear behavior of the vibration of the drill string are investigated. The results obtained demonstrate that, the axial vibration response of the drill string system shows an overall trend of quasi-periodic-chaotic change with the increase of feed rate, and the torsional vibration of the drill string shows the trend of quasi periodic-chaotic. When the feed rate is high, the vibration of the drill string system is mainly for the irregular and complex hybrid motion. Therefore, the appropriate reduction of feed speed can increase the stability of the drill string on-site, and reduce the jump drilling and stick-slip vibration of the drill string. When the rotary drilling speed is 90–210 rpm, the torsional vibration response of the drill string shows a chaotic-quasi-periodic trend and the complexity of the torsional vibration of the drill string decreases with the increase of rotary drilling speed. The axial vibration response of the drill string shows a chaotic-quasi-periodic-chaotic trend with the increase of the rotary drilling speed. When the rotary drilling speed increases to 400–410 rpm, the axial vibration of the drill string becomes a quasi-periodic motion. Therefore, increasing the rotary drilling speed within a certain range can reduce the complexity of the vibration of the drill string and reduce the skip and stick-slip vibration of the drill string.

中文翻译：

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油气井轴扭耦合振动模型及钻柱系统非线性行为


针对油气井钻柱轴扭耦合振动的失效问题，采用有限元方法建立了钻柱轴扭耦合非线性振动模型，可有效模拟实际井筒钻柱多体系统的耦合振动和实时破岩效果。此外，通过类似的油管振动实验验证了理论模型的正确性和有效性。最后，研究了进给速度和旋转钻孔速度对钻柱振动非线性行为的影响。所得结果表明，钻柱系统的轴向振动响应随进给速率的增加呈现准周期性-混沌变化的总体趋势，钻柱的扭转振动表现出准周期性-混沌的趋势。当进给速度较高时，钻柱系统的振动主要针对不规则和复杂的混合运动。因此，适当降低进给速度可以增加钻柱在现场的稳定性，减少钻柱的跳钻和粘滑振动。当旋转钻孔速度为 90–210 rpm 时，钻柱的扭转振动响应呈现混沌-准-周期性的趋势，钻柱扭转振动的复杂度随着旋转钻孔速度的增加而降低。钻柱的轴向振动响应随旋转钻孔速度的增加呈混沌-准-周期-混沌趋势。当旋转钻孔速度增加到 400-410 rpm 时，钻柱的轴向振动变为准周期运动。 因此，在一定范围内提高旋转钻进速度，可以降低钻柱振动的复杂度，减少钻柱的跳滑振动。