Dynamic Characteristics of Downhole Bit Load and Analysis of Conversion Efficiency of Drill String Vibration Energy

The longitudinal vibration of the drill pipe contains considerable energy which can be used to improve rock-breaking efficiency during drilling. It is very important development drilling speed-up tools have a comprehensive understanding conversion downhole string vibration. In this paper, characteristics bit load and under different conditions were studied in experiment, analysis method from spring potential was proposed. experimental showed that fluctuation reduced by 10%–90% after installed bottom hole assembly. rotation rate elastic stiffness had significant positive influence on amplitude load. Meanwhile, acceleration peaked at 1 kN/mm. closer position was, more severe above component was. severity available mechanical range about 200–420 kW. work power increased sharply then decreased with increasing stiffness. came optimal value when between kN/mm 2 Increasing rate, keeping below 134.5 kN installing near are beneficial for improving This paper reveals main factors affecting their influencing laws, determines WOB, speed, obtain best efficiency.