The Working Mechanism And Experimental Research Of The Torque Impactor

With the development and popularity of the deep well and ultra-deep well, the stick-slip and sticking phenomenon in the drilling process has been the most important problems to be resolved. Aiming at this problem, many domestic and international scholars have made a large number of researches. Based on the study of the stick-slip phenomenon, it can be found that there is no method to settle this phenomenon essentially unless the drill string’s force is changed. To change the force of drill string system, a new downhole tool named torsion oscillator is presented, which is analyzed by the method of mechanics, mathematics, calculation and experiment.The structure design and working principle of the torsion oscillator are induced particularly, which provides the basis of its movement behavior analysis. According to the torsion oscillator structure, the characteristics of the performance are researched. From the analysis results, the part of hydraulic energy of the drilling fluid can be transformed into mechanical energy through the torsion oscillator. And the periodical and reciprocating torque acted on the drill bit changes the force of drill string system and improves the rock-breaking efficiency and rate of penetration (ROP).In accordance with the difference of the kinetic characteristics, the key components of the torsion oscillator are studied respectively, which the emphasis are impact frequency of the torsion oscillator, angular velocity and angular displacement of hydraulic hammer, fork switch and valve body. The torque of the torsion oscillator is researched based on its regular and the average torque is obtained as well as its vibration model under ideal conditions. Combined with specific conditions, the vibration model of the drill string with the torsion oscillator and the wear model of the cutting teeth of polycrystalline diamond compact (PDC) are researched. It can be seen that the curve regulation of the angular velocity and angular displacement are zigzag under the drill string vibration influence of the torkbuste, and the wear is smaller compared with the general downhole tool.In order to verify the accuracy of this method, the experimental research of torsion is conducted in this paper. The bench experiments verify the accuracy of the collision frequency and average torque of the torsion oscillator. The downhole experiments verify the actual effect of improving the ROP and reducing the wear of cutting teeth with the torsion oscillator. These two experiments provide a certain theoretical basis for the mechanism research and field application of the torsion oscillator.In conclusion, the structural design and performance analysis of the torsion oscillator and the kinematics of its key component are mainly researched, as well as the effects of the important performance index, including the inlet flow and collision frequency. Based on the kinematic model, the torque model of the torlbuster is established, and the influence of drill string vibration and wear mechanism of the cutting teeth. On this basis, the downhole experiment of torsion oscillator are conducted, which verify the accuracy of theoretical model and field application and provide certain reference significance to improve the theory on downhole tools.