Study On Torsional Vibration Characteristics Of Coal Seam Drilling Drill Bods

As the main source of my country,now,with the increase in the depth of coal mines,gas content is gradually increased,gas disaster is increasing,preventing and curbing major gas accidents is the main task of current coal mine safety production.The torsional vibration of the drill pipe will result in the failure of the drilling.For example,the drilling equipment is worn,and the drilling cycle is less efficient,so the research on the punching vibration of the drill pipe system is very necessary.By reasonably simplifying and assuming the drill pipe system,this paper establishes a mechanical model of a two-degree-of-freedom drill pipe system,which fully considers the interaction between the drill bit and the formation,analyzes the stick-slip vibration model,and derives the drill pipe The differential equation of motion for system stick-slip vibration.Use MATLAB software programming to solve and analyze the stick-slip vibration response.Take a 300 m drill pipe system as an example to study and analyze the four-stage response law of angular displacement,angular velocity,resistance torque,driving torque,relative motion phase trajectory,and stick-slip vibration.A detailed introduction is given to further obtain the stick-slip vibration response law of the drill pipe system.The motion parameters of the drill pipe system have a huge impact on the stick-slip vibration response law.Therefore,by changing the system parameters(such as drill pipe length,weight on bit,drilling speed of the drill power head),according to the motion equation of the stick-slip vibration of the drill bit,the stick-slip vibration The sliding vibration response equation is solved and analyzed.The results show that when the length of the drill pipe and the weight on bit are larger,the rotation speed of the power head of the drill rig is smaller,and the stick-slip vibration of the drill pipe system is more likely to occur.When the stick-slip vibration of the drill pipe system occurs,the angular velocity of the drill bit will alternately cyclically move between the viscous phase and the sliding stage,and the phase trajectory curve at the drill bit will show a stable limit cycle.When the drill pipe system does not experience stick-slip vibration When,the angular velocity of the drill bit will keep rotating at a constant speed,and the phase trajectory curve will appear in the shape of a spiral ring.According to the similarity theory,the drill pipe model of the gas drainage site is reduced to a certain scale,and the torsional vibration test bench of the gas drainage drill pipe is built.The torsional vibration experiment of the drill pipe system under different working conditions such as rotation speed,rod length and load is carried out.The results show that as the length of the drill rod,the speed of the power head of the drill rig and the load increase,the standard deviation of the time history data becomes larger and the torsional vibration of the drill rod becomes more severe...