钻杆纵-扭耦合振动的试验研究

Experimental research on coupled axial-torsional vibration of drill strings

提出了一种新型的钻杆纵-扭耦合振动模拟测试系统。基于该系统设计了单因素试验,研究了驱动转速、进给速度、钻头直径、岩样强度和钻杆刚度对钻杆振动的影响规律,并通过正交试验探究了以上各因素对钻杆振动的影响程度。单因素试验结果表明,随着转速的增加,纵向振动幅值先减小后增大,但扭转振动幅值逐渐减小;随着进给速度的增大,纵向振动幅值逐渐减小,但扭转振动的幅值逐渐增大;转速增加导致扭矩和钻压下降,而进给速度增加导致扭矩和钻压上升;采用小直径钻头,低强度岩样,低刚度钻杆均有助于减小钻杆纵向振动幅值,但均导致扭转振动幅值增加。正交试验结果表明,转速对纵向振动的影响程度最大,进给速度对扭转振动的影响程度最大。试验结果与已有钻杆纵-扭耦合振动两自由度模型的数值仿真结果基本吻合。

In this paper,a new test system for simulating the axial-torsional coupling vibration of drill strings was proposed.Based on this system,a single-factor experiment was designed,and the influence of driving speed,feed speed,drill bit diameter,rock sample strength and drill string stiffness on drill string vibration was studied,and the influence of the above factors on drill string vibration was explored through orthogonal experiments.The single-factor experimental results show that with the increase of rotational speed,the axial vibration amplitude first decreases and then increases,but the torsional vibration amplitude gradually decreases.With the increase of feed speed,the amplitude of axial vibration gradually decreases,but the amplitude of torsional vibration gradually increases.The increase in speed leads to decrease in torque and drilling pressure,while an increase in feed speed leads to increase in torque and drilling pressure.The use of small diameter drill bits,low strength rock samples,and low stiffness drill strings all help to reduce the axial vibration amplitude of the drill strings,but all lead to increase in the torsional vibration amplitude.The orthogonal experimental results show that the speed has the greatest influence on the axial vibration,and the feed speed has the greatest influence on the torsional vibration.The experimental results are basically consistent with the prediction results of the numerical simulation of the axial-torsional coupling model of two-degree-of-freedom drill strings.