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Load fluctuation characteristics have a great influence on drilling performance. So, study the influence of drilling kinematic parameters on the load fluctuation characteristics of PDC bit becomes more and more important. Gas drainage drilling experiment table was built and Gas drainage drilling experiment was carried out under different feed speed, different rotation speed and same drilling thickness with different feed speed and rotation speed. The results indicate that drilling torque decreases with the increase of rotation speed; vibration amplitude of drilling torque increases with increase of rotation speed. Vibration amplitude of feed resistance decreases from 90 r/min to about 240 r/min and then increases. The value of 240 r/min is minimum. Feed resistance and drilling torque increase with the increase of feeding speed. Vibration amplitude of drilling torque and feeding resistance increases with the increase of feeding speed. Feed resistance and drilling torque are almost equal with the same drilling thickness; meanwhile, vibration amplitude of drilling torque and feed resistance increases with the increase of feeding speed. It provides a good basis for setting the appropriate feeding speed and rotation speed in actual work.

Study of Load Fluctuation Characteristics of PDC Bit during Gas Extraction Borehole in Soft Coal Seam