钻柱黏滑振动动力学研究

The Simulation and Analysis of Drillstring Stick-slip Vibration

以四自由度钻柱动力学方程为基础,结合钻头–岩石的相互作用规律,分析了钻柱在直井眼内的动力学特征,研发了多自由度钻柱粘滑振动仿真软件。利用该软件开展了钻柱动力学行为影响的单因素分析,得出了管柱、钻头和转盘的刚度与转动惯量,以及钻压、转速等对钻柱动力学行为的影响规律,获得了钻柱运动的4种状态特征。通过对实际钻柱动力学参数的仿真分析,表明钻杆越长,钻铤越短,钻柱越容易处于黏滑振动状态。另外,改变钻柱的内外直径不可能有效抑制黏滑振动。研究成果对现场钻井作业具有非常实用的指导意义。

In this paper,based on dynamical equation of the drillstring of four degrees of freedom and bit-rock interaction law, we analyzed the dynamic characteristics of drillstring in straight borehole. And the systemic simulation software of a multi-DOF drillstring stick-slip vibration is developed. Using this software,we made the simulation research on the influence of single factor on the dynamic behavior of the drillstring. And we also derived the influence of the stiffness and the moment of inertia of the drillstring,the bit and the rotary table,and WOB,speed,etc. on the dynamic behavior of the drillstring. In addition, the four state characteristics of the movement of the drillstring are obtained. Further practical dynamic parameter simulation of the drillstring,reveals that the longer the drillpipes are,or the shorter the drillcollars,the more likely the drillstring is in a stick-slip vibration state. In addition,changing the inner and outer diameters of the drillstring is unlikely to effectively suppress the stick-slip effect. Obviously,these results have very practical significance for on-site drilling process.