锥形PDC齿耐磨性能试验研究

Wear Resistance Test of Conical PDC Cutter

犁削型PDC钻头采用异于常规PDC复合片的锥形PDC齿作为切削单元,具备钻进硬地层的能力。利用VTL机床对锥形齿进行了磨损试验,研究了不同切削角和不同齿形对锥形PDC齿耐磨性能的影响,优选出耐磨性能好的齿形及切削角,并与常规PDC齿的耐磨性能进行对比。研究结果表明,当锥顶角一定时,随着正切削角由5°增大到21°,锥形PDC齿的耐磨性能呈现由弱变强,再由强变弱的趋势,正切削角在12°~17°时锥形PDC齿的耐磨性能最好;当正切削角一定时,在锥顶角由68°增大到75°的过程中,锥形PDC齿的耐磨性能下降。为提高锥形PDC齿的耐磨性能,应设计适合锥形PDC齿的具有较大合成腔室的顶压机,同时对钻头水力参数进行优化。

Ploughing cutting type of PDC bit is capable of drilling hard formations by using conical PDC cutter which is different from the conventional PDC cutter. The conical PDC cutter has been conduct wear resistance test u- sing VTL machine to study the effects of cutting angle, cutter shape on the wear resistance of PDC cutter. A better wear-resistance cutter has been gained by optimizing the cutter shape and the cutting angle, and compared with the conventional PDC cutter. The results show that, given the same taper angle, the wear resistance performance in- creases but then decreases with the cutting angle increasing from 5° to 21°, and the best wear resistance perform- ance will be achieved between the cutting angle of 12° - 17°. Given the same cutting angle, the wear resistance performance decreased with the taper angle increasing from 68° to 75°. To improve the wear resistance of conical PDC cutter, a hinge press with larger compound chamber should be designed, and the drilling hydraulic parame- ters should also be optimized.